What is in lipoproteins in a blood test. Lipoproteins (lipoproteins): all types. Alpha and beta cholesterol - what is it

The organs of our body (internal organs), such as the heart, intestines, and stomach, are regulated by parts of the nervous system known as the autonomic nervous system. The autonomic nervous system is part of the peripheral nervous system and regulates the function of many muscles, glands, and organs in the body. We are usually completely unaware of the functioning of our autonomic nervous system because it functions in a reflex and involuntary manner. For example, we don't know when our blood vessels have changed size, and we (usually) don't know when our heartbeat has accelerated or slowed down.

What is the autonomic nervous system?

The autonomic nervous system (ANS) is an involuntary part of the nervous system. It consists of autonomic neurons that conduct impulses from the central nervous system (brain and/or spinal cord), to glands, smooth muscles, and to the heart. ANS neurons are responsible for regulating the secretion of certain glands (eg, salivary glands), regulating heart rate and peristalsis (contractions of smooth muscles in the digestive tract), and other functions.

Role of the VNS

The role of the ANS is to constantly regulate the functions of organs and organ systems, in accordance with internal and external stimuli. The ANS helps maintain homeostasis (regulation of the internal environment) by coordinating various functions such as hormone secretion, circulation, respiration, digestion, and excretion. The ANS always functions unconsciously, we do not know which of the important tasks it performs every minute of every day.
The ANS is divided into two subsystems, SNS (sympathetic nervous system) and PNS (parasympathetic nervous system).

Sympathetic Nervous System (SNS) - triggers what is commonly known as the "fight or flight" response

Sympathetic neurons usually belong to the peripheral nervous system, although some of the sympathetic neurons are located in the CNS (central nervous system)

Sympathetic neurons in the CNS (spinal cord) communicate with peripheral sympathetic neurons through a series of sympathetic nerve cells in the body known as ganglia.

Through chemical synapses within the ganglia, sympathetic neurons attach peripheral sympathetic neurons (for this reason, the terms "presynaptic" and "postsynaptic" are used to refer to spinal cord sympathetic neurons and peripheral sympathetic neurons, respectively)

Presynaptic neurons release acetylcholine at synapses within the sympathetic ganglia. Acetylcholine (ACh) is a chemical messenger that binds nicotinic acetylcholine receptors in postsynaptic neurons.

Post-synaptic neurons release norepinephrine (NA) in response to this stimulus.

Continued excitation response can cause adrenaline to be released from the adrenal glands (particularly from the adrenal medulla)

Once released, norepinephrine and epinephrine bind to adrenoreceptors in various tissues, resulting in a characteristic "fight or flight" effect.

The following effects are manifested as a result of the activation of adrenergic receptors:

Increased sweating
weakening of peristalsis
increase in heart rate (increase in conduction velocity, decrease in refractory period)
dilated pupils
increased blood pressure (increased number of heartbeats to relax and fill up)

Parasympathetic Nervous System (PNS) - The PNS is sometimes referred to as the "rest and digest" system. In general, the PNS operates in the opposite direction to the SNS, eliminating the consequences of the "fight or flight" response. However, it is more correct to say that SNA and PNS complement each other.

The PNS uses acetylcholine as the main neurotransmitter
When stimulated, presynaptic nerve endings release acetylcholine (ACh) into the ganglion
ACh, in turn, acts on nicotinic receptors of postsynaptic neurons
postsynaptic nerves then release acetylcholine to stimulate the target organ's muscarinic receptors

The following effects are manifested as a result of activation of the PNS:

Decreased sweating
increased peristalsis
decrease in heart rate (decrease in conduction velocity, increase in refractory period)
pupillary constriction
lowering blood pressure (reducing the number of heartbeats to relax and fill up)

SNS and PNS conductors

The autonomic nervous system releases chemical vehicles to influence its target organs. The most common are norepinephrine (NA) and acetylcholine (ACH). All presynaptic neurons use ACh as a neurotransmitter. ACh also releases some sympathetic postsynaptic neurons and all parasympathetic postsynaptic neurons. The SNS uses HA as the basis of the postsynaptic chemical messenger. HA and ACh are the best known ANS mediators. In addition to neurotransmitters, several vasoactive substances are released by automatic postsynaptic neurons that bind to receptors on target cells and affect the target organ.

How is SNS conduction carried out?

In the sympathetic nervous system, catecholamines (norepinephrine, epinephrine) act on specific receptors located on the cell surface of target organs. These receptors are called adrenergic receptors.

Alpha-1 receptors exert their action on smooth muscle, mainly in contraction. Effects may include constriction of arteries and veins, decreased mobility in the GI (gastrointestinal tract), and constriction of the pupil. Alpha-1 receptors are usually located postsynaptically.

Alpha 2 receptors bind epinephrine and norepinephrine, thereby reducing the influence of alpha 1 receptors to some extent. However, alpha 2 receptors have several independent specific functions, including vasoconstriction. Functions may include coronary artery contraction, smooth muscle contraction, vein contraction, decreased intestinal motility, and inhibition of insulin release.

Beta-1 receptors act primarily on the heart, causing an increase in cardiac output, contraction rate, and an increase in cardiac conduction, resulting in an increase in heart rate. It also stimulates the salivary glands.

Beta-2 receptors act mainly on skeletal and cardiac muscles. They increase the speed of muscle contraction, and also dilate blood vessels. The receptors are stimulated by the circulation of neurotransmitters (catecholamines).

How is the conduction of the PNS carried out?

As already mentioned, acetylcholine is the main mediator of the PNS. Acetylcholine acts on cholinergic receptors known as muscarinic and nicotinic receptors. Muscarinic receptors exert their influence on the heart. There are two main muscarinic receptors:

M2 receptors are located in the very center, M2 receptors - act on acetylcholine, stimulation of these receptors causes the heart to slow down (reducing heart rate and increasing refractoriness).

M3 receptors are located throughout the body, activation leads to an increase in nitric oxide synthesis, which leads to relaxation of cardiac smooth muscle cells.

How is the autonomic nervous system organized?

As discussed earlier, the autonomic nervous system is divided into two distinct divisions: the sympathetic nervous system and the parasympathetic nervous system. It is important to understand how these two systems function in order to determine how they affect the body, keeping in mind that both systems work in synergy to maintain homeostasis in the body.
Both the sympathetic and parasympathetic nerves release neurotransmitters, primarily norepinephrine and epinephrine for the sympathetic nervous system, and acetylcholine for the parasympathetic nervous system.
These neurotransmitters (also called catecholamines) transmit nerve signals across the gaps (synapses) created when the nerve connects to other nerves, cells, or organs. Then, neurotransmitters applied either to sympathetic receptor sites or parasympathetic receptors on the target organ exert their influence. This is a simplified version of the functions of the autonomic nervous system.

How is the autonomic nervous system controlled?

The ANS is not under conscious control. There are several centers that play a role in ANS control:

Cerebral cortex - areas of the cerebral cortex control homeostasis by regulating the SNS, PNS and hypothalamus.

Limbic System - The limbic system consists of the hypothalamus, amygdala, hippocampus, and other nearby components. These structures lie on both sides of the thalamus, just below the brain.

The hypothalamus is the hypothalamic region of the diencephalon that controls the ANS. The area of ​​the hypothalamus includes the parasympathetic vagus nuclei as well as a group of cells that lead to the sympathetic system in the spinal cord. By interacting with these systems, the hypothalamus controls digestion, heart rate, sweating, and other functions.

Stem Brain – The stem brain acts as a link between the spinal cord and the brain. Sensory and motor neurons travel through the brainstem to relay messages between the brain and spinal cord. The brainstem controls many autonomic functions of the PNS, including respiration, heart rate, and blood pressure.

Spinal Cord - There are two chains of ganglia on either side of the spinal cord. The outer circuits are formed by the parasympathetic nervous system, while the circuits close to the spinal cord form the sympathetic element.

What are the receptors of the autonomic nervous system?

Afferent neurons, dendrites of neurons that have receptor properties, are highly specialized, receiving only certain types of stimuli. We do not consciously feel impulses from these receptors (with the possible exception of pain). There are numerous sensory receptors:

Photoreceptors - react to light
thermoreceptors - respond to changes in temperature
Mechanoreceptors – respond to stretch and pressure (blood pressure or touch)
Chemoreceptors - respond to changes in the internal chemical composition of the body (i.e., O2, CO2 content) of dissolved chemicals, taste and smell sensations
Nociceptors - respond to various stimuli associated with tissue damage (the brain interprets pain)

Autonomous (visceral) motor neurons of the synapse on neurons, located in the ganglia of the sympathetic and parasympathetic nervous systems, directly innervate the muscles and some glands. Thus, it can be said that visceral motor neurons indirectly innervate the smooth muscles of the arteries and the heart muscle. Autonomic motor neurons work by increasing the SNS or decreasing the PNS of their activity in target tissues. In addition, autonomic motor neurons can continue to function even if their nerve supply is damaged, albeit to a lesser extent.

Where are the autonomic neurons of the nervous system located?

The ANS essentially consists of two types of neurons connected in a group. The nucleus of the first neuron is located in the central nervous system (SNS neurons originate in the thoracic and lumbar regions of the spinal cord, PNS neurons originate in the cranial nerves and sacral spinal cord). The axons of the first neuron are located in the autonomic ganglia. From the point of view of the second neuron, its nucleus is located in the autonomic ganglion, while the axons of the second neurons are located in the target tissue. The two types of giant neurons communicate using acetylcholine. However, the second neuron communicates with the target tissue via acetylcholine (PNS) or noradrenaline (SNS). So the PNS and SNS are connected to the hypothalamus.

	Sympathetic	Parasympathetic
Function	Protecting the body from attack	Heals, regenerates and nourishes the body
Overall effect	Catabolic (destroys the body)	Anabolic (builds the body)
Activation of organs and glands	Brain, muscles, pancreatic insulin, thyroid and adrenal glands	Liver, kidneys, pancreatic enzymes, spleen, stomach, small and large intestines
Increase in hormones and other substances	Insulin, cortisol and thyroid hormone	Parathyroid hormone, pancreatic enzymes, bile and other digestive enzymes
It activates body functions	Increases blood pressure and blood sugar, increases heat energy production	Activates digestion, immune system and excretory function
Psychological qualities	Fear, guilt, sadness, anger, willfulness and aggressiveness	Serenity, satisfaction and relaxation
Factors that activate this system	Stress, fear, anger, anxiety, overthinking, increased physical activity	Rest, sleep, meditation, relaxation and the feeling of true love

Overview of the Autonomic Nervous System

Autonomic functions of the nervous system for life support, have control over the following functions / systems:

Heart (control of heart rate by contraction, refractory state, cardiac conduction)
Blood vessels (constriction and dilation of arteries/veins)
Lungs (relaxation of the smooth muscles of the bronchioles)
digestive system (gastrointestinal motility, saliva production, sphincter control, insulin production in the pancreas, and so on)
Immune system (mast cell inhibition)
Fluid balance (renal artery narrowing, renin secretion)
Pupil diameter (constriction and expansion of the pupil and ciliary muscle)
sweating (stimulates the secretion of sweat glands)
Reproductive system (in men, erection and ejaculation; in women, contraction and relaxation of the uterus)
From the urinary system (relaxation and contraction of the bladder and detrusor, urethral sphincter)

The ANS, through its two branches (sympathetic and parasympathetic), controls energy expenditure. The sympathetic is the mediator of these costs, while the parasympathetic serves a general strengthening function. All in all:

The sympathetic nervous system causes an acceleration of bodily functions (i.e. heart rate and respiration) protects the heart, shunts blood from the extremities to the center

The parasympathetic nervous system causes a slowdown in bodily functions (i.e. heart rate and breathing) promotes healing, rest and recovery, and coordinates immune responses

Health can be adversely affected when the influence of one of these systems is not established with the other, resulting in disturbed homeostasis. The ANS affects changes in the body that are temporary, in other words, the body must return to its basic state. Naturally, there should not be a rapid excursion from the homeostatic baseline, but a return to the original level should occur in a timely manner. When one system is stubbornly activated (increased tone), health may suffer.
The departments of an autonomous system are designed to oppose (and thus balance) each other. For example, when the sympathetic nervous system begins to work, the parasympathetic nervous system begins to act to bring the sympathetic nervous system back to its original level. Thus, it is not difficult to understand that the constant action of one department, can cause a constant decrease in tone in another, which can lead to poor health. A balance between these two is essential for health.
The parasympathetic nervous system has a faster ability to respond to changes than the sympathetic nervous system. Why have we developed this path? Imagine if we had not developed it: the impact of stress causes tachycardia, if the parasympathetic system does not immediately begin to resist, then the increase in heart rate, heart rate can continue to rise to a dangerous rhythm, such as ventricular fibrillation. Because the parasympathetic is able to react so quickly, a dangerous situation like this cannot occur. The parasympathetic nervous system is the first to indicate changes in the state of health in the body. The parasympathetic system is the main factor influencing respiratory activity. Regarding the heart, parasympathetic nerve fibers synapse deep inside the heart muscle, while sympathetic nerve fibers synapse on the surface of the heart. Thus, the parasympathetics are more sensitive to damage to the heart.

Transmission of autonomic impulses

Neurons generate and propagate action potentials along axons. They then signal across the synapse by releasing chemicals called neurotransmitters that stimulate a response in another effector cell or neuron. This process can lead to either stimulation or inhibition of the host cell, depending on the involvement of neurotransmitters and receptors.

Propagation along the axon, propagation of the potential along the axon is electrical and occurs by the exchange of + ions through the axon membrane of sodium (Na +) and potassium (K +) channels. Individual neurons generate the same potential after receiving each stimulus and conduct the potential at a fixed rate along the axon. Velocity depends on the diameter of the axon and how strongly it is myelinated—velocity is faster in myelinated fibers because the axon is exposed at regular intervals (nodes of Ranvier). The impulse "jumps" from one node to another, skipping the myelinated sections.
Transmission is a chemical transmission resulting from the release of specific neurotransmitters from a terminal (nerve ending). These neurotransmitters diffuse across the synapse cleft and bind to specific receptors that are attached to the effector cell or adjacent neuron. The response can be excitatory or inhibitory depending on the receptor. The mediator-receptor interaction must occur and be completed quickly. This allows multiple and rapid activation of the receptors. Neurotransmitters can be "reused" in one of three ways.

Reuptake - neurotransmitters are rapidly pumped back into presynaptic nerve endings
Destruction - neurotransmitters are destroyed by enzymes located near the receptors
Diffusion – neurotransmitters can diffuse into the surroundings and eventually be removed

Receptors - Receptors are protein complexes that cover the cell membrane. Most interact mainly with postsynaptic receptors, and some are located on presynaptic neurons, which allows more precise control of the release of neurotransmitters. There are two main neurotransmitters in the autonomic nervous system:

Acetylcholine is the main neurotransmitter of autonomic presynaptic fibers, postsynaptic parasympathetic fibers.
Norepinephrine is the mediator of most postsynaptic sympathetic fibers.

parasympathetic system

The answer is "rest and assimilation".:

Increases blood flow to the gastrointestinal tract, which contributes to the satisfaction of many metabolic needs of the organs of the gastrointestinal tract.
Constricts bronchioles when oxygen levels are normalized.
Controls the heart, parts of the heart through the vagus nerve and accessory nerves of the thoracic spinal cord.
Constricts the pupil, allows you to control near vision.
Stimulates salivary gland production and speeds up peristalsis to aid digestion.
Relaxation/contraction of the uterus and erection/ejaculation in men

In order to understand the functioning of the parasympathetic nervous system, it would be helpful to use a real-life example:
The male sexual response is under the direct control of the central nervous system. Erection is controlled by the parasympathetic system through excitatory pathways. Excitatory signals originate in the brain through thought, sight, or direct stimulation. Regardless of the origin of the nerve signal, the nerves of the penis respond by releasing acetylcholine and nitric oxide, which in turn sends a signal to the smooth muscle of the penile arteries to relax and fill them with blood. This series of events leads to an erection.

Sympathetic system

Fight or flight response:

Stimulates the sweat glands.
Constricts peripheral blood vessels, shunts blood to the heart where it is needed.
Increases blood supply to skeletal muscles that may be required for work.
Expansion of bronchioles in conditions of low oxygen content in the blood.
Decreased blood flow to the abdomen, decreased peristalsis and digestive activity.
release of glucose stores from the liver increasing blood glucose levels.

As in the section on the parasympathetic system, it is helpful to look at a real-life example to understand how the functions of the sympathetic nervous system work:
An extremely high temperature is a stress that many of us have experienced. When we are exposed to high temperatures, our bodies react in the following way: heat receptors transmit impulses to sympathetic control centers located in the brain. Inhibitory messages are sent along sympathetic nerves to skin blood vessels, which dilate in response. This dilation of blood vessels increases blood flow to the surface of the body so that heat can be lost through radiation from the surface of the body. In addition to dilating the skin's blood vessels, the body also reacts to high temperatures by sweating. It does this by increasing body temperature, which is sensed by the hypothalamus, which sends a signal through the sympathetic nerves to the sweat glands to increase the production of sweat. Heat is lost by evaporation of the resulting sweat.

autonomic neurons

Neurons that conduct impulses from the central nervous system are known as efferent (motor) neurons. They differ from somatic motor neurons in that efferent neurons are not under conscious control. Somatic neurons send axons to skeletal muscles, which are normally under conscious control.

Visceral efferent neurons are motor neurons, their job is to conduct impulses to the heart muscle, smooth muscles and glands. They can originate in the brain or spinal cord (CNS). Both visceral efferent neurons require conduction from the brain or spinal cord to the target tissue.

Preganglionic (presynaptic) neurons - the cell body of the neuron is located in the gray matter of the spinal cord or brain. It ends in the sympathetic or parasympathetic ganglion.

Preganglionic autonomic fibers - can originate in the hindbrain, midbrain, in the thoracic spinal cord, or at the level of the fourth sacral segment of the spinal cord. Autonomic ganglia can be found in the head, neck, or abdomen. Chains of autonomic ganglia also run parallel on each side of the spinal cord.

The postganglionic (postsynaptic) cell body of a neuron is located in the autonomic ganglion (sympathetic or parasympathetic). The neuron ends in a visceral structure (target tissue).

Where preganglionic fibers originate and autonomic ganglia meet helps in differentiating between the sympathetic nervous system and the parasympathetic nervous system.

Divisions of the autonomic nervous system

A summary of the sections of the VNS:

Consists of internal organs (motor) efferent fibers.

Divided into sympathetic and parasympathetic divisions.

Sympathetic CNS neurons exit via spinal nerves located in the lumbar/thoracic region of the spinal cord.

Parasympathetic neurons exit the CNS through the cranial nerves, as well as the spinal nerves located in the sacral spinal cord.

There are always two neurons involved in the transmission of a nerve impulse: presynaptic (preganglionic) and postsynaptic (postganglionic).

Sympathetic preganglionic neurons are relatively short; postganglionic sympathetic neurons are relatively long.

Parasympathetic preganglionic neurons are relatively long, postganglionic parasympathetic neurons are relatively short.

All ANS neurons are either adrenergic or cholinergic.

Cholinergic neurons use acetylcholine (ACh) as their neurotransmitter (including: preganglionic neurons of the SNS and PNS sections, all postganglionic neurons of the PNS sections, and postganglionic neurons of the SNS sections that act on the sweat glands).

Adrenergic neurons use norepinephrine (NA) as do their neurotransmitters (including all postganglionic SNS neurons except those that act on the sweat glands).

adrenal glands

The adrenal glands located above each kidney are also known as the adrenal glands. They are located approximately at the level of the 12th thoracic vertebra. The adrenal glands are made up of two parts, the superficial layer, the cortex, and the inner, medulla. Both parts produce hormones: the outer cortex produces aldosterone, androgen, and cortisol, while the medulla mainly produces epinephrine and norepinephrine. The medulla releases epinephrine and norepinephrine when the body responds to stress (i.e. the SNS is activated) directly into the bloodstream.
The cells of the adrenal medulla are derived from the same embryonic tissue as the sympathetic postganglionic neurons, so the medulla is related to the sympathetic ganglion. Brain cells are innervated by sympathetic preganglionic fibers. In response to nervous excitement, the medulla releases adrenaline into the blood. The effects of epinephrine are similar to norepinephrine.
The hormones produced by the adrenal glands are critical to the normal healthy functioning of the body. Cortisol released in response to chronic stress (or increased sympathetic tone) can harm the body (eg, increase blood pressure, alter immune function). If the body is under stress for a long period of time, cortisol levels can be deficient (adrenal fatigue), causing low blood sugar, excessive fatigue and muscle pain.

Parasympathetic (craniosacral) division

The division of the parasympathetic autonomic nervous system is often referred to as the craniosacral division. This is due to the fact that the cell bodies of preganglionic neurons are located in the nuclei of the brain stem, as well as in the lateral horns of the spinal cord and from the 2nd to 4th sacral segments of the spinal cord, therefore, the term craniosacral is often used to refer to the parasympathetic region.

Parasympathetic cranial output:
Consists of myelinated preganglionic axons that arise from the brainstem in the cranial nerves (lll, Vll, lX and X).
Has five components.
The largest is the vagus nerve (X), which conducts preganglionic fibers, contains about 80% of the total outflow.
Axons end at the end of the ganglia in the walls of the target (effector) organs, where they synapse with ganglionic neurons.

Parasympathetic sacral release:
Consists of myelinated preganglionic axons that arise in the anterior roots of the 2nd to 4th sacral nerves.
Together they form the pelvic splanchnic nerves, with ganglionic neurons synapsing in the walls of the reproductive/excretory organs.

Functions of the autonomic nervous system

The three mnemonic factors (fear, fight, or flight) make it easy to predict how the sympathetic nervous system works. When faced with a situation of intense fear, anxiety or stress, the body reacts by speeding up the heart rate, increasing blood flow to vital organs and muscles, slowing down digestion, making changes in our vision to allow us to see the best, and many other changes. which allow us to react quickly in dangerous or stressful situations. These reactions have allowed us to survive as a species for thousands of years.
As is often the case with the human body, the sympathetic system is perfectly balanced by the parasympathetic system, which brings our system back to normal once the sympathetic department is activated. The parasympathetic system not only restores balance, but also performs other important functions, reproduction, digestion, rest and sleep. Each division uses different neurotransmitters to carry out activities - in the sympathetic nervous system, norepinephrine and epinephrine are the neurotransmitters of choice, while the parasympathetic division uses acetylcholine to perform its duties.

Neurotransmitters of the autonomic nervous system

This table describes the main neurotransmitters from the sympathetic and parasympathetic divisions. There are a few special situations to note:

Some sympathetic fibers that innervate sweat glands and blood vessels within skeletal muscles secrete acetylcholine.
Adrenal medulla cells are closely associated with postganglionic sympathetic neurons; they secrete epinephrine and norepinephrine, as do postganglionic sympathetic neurons.

Receptors of the autonomic nervous system

The following table shows the ANS receptors, including their locations

Receptors	Departments of VNS	Localization	Adrenergic and Cholinergic
Nicotinic receptors	Parasympathetic	ANS (parasympathetic and sympathetic) ganglia; muscle cell	Cholinergic
Muscarinic receptors (M2, M3 affecting cardiovascular activity)	Parasympathetic	M-2 are localized in the heart (with the action of acetylcholine); M3 - found in the arterial tree (nitric oxide)	Cholinergic
Alpha-1 receptors	Sympathetic	mainly located in the blood vessels; mostly located postsynaptically.	Adrenergic
Alpha-2 receptors	Sympathetic	Localized presynaptically on nerve endings; also localized distally to the synaptic cleft	Adrenergic
Beta-1 receptors	Sympathetic	lipocytes; conducting system of the heart	Adrenergic
Beta-2 receptors	Sympathetic	located mainly on arteries (coronary and skeletal muscle)	Adrenergic

Agonists and Antagonists

In order to understand how some drugs affect the autonomic nervous system, it is necessary to define some terms:

Sympathetic agonist (sympathomimetic) - a drug that stimulates the sympathetic nervous system
Sympathetic antagonist (sympatholytic) - a drug that inhibits the sympathetic nervous system
Parasympathetic agonist (parasympathomimetic) - a drug that stimulates the parasympathetic nervous system
Parasympathetic antagonist (parasympatholytic) - a drug that inhibits the parasympathetic nervous system

(One way to keep direct terms is to think of the suffix - mimetic means "imitate", in other words, it mimics the action, Lytic usually means "destruction", so you can think of the suffix - lytic as inhibiting or destroying the action of the system in question) .

Response to adrenergic stimulation

Adrenergic responses in the body are stimulated by compounds that are chemically similar to adrenaline. Norepinephrine, which is released from sympathetic nerve endings, and epinephrine (adrenaline) in the blood are the most important adrenergic transmitters. Adrenergic stimulants can have both excitatory and inhibitory effects, depending on the type of receptor on the effector (target) organs:

Effect on the target organ	Stimulant or inhibitory action
pupil dilation	stimulated
Decreased secretion of saliva	inhibited
Increased heart rate	stimulated
Increase in cardiac output	stimulated
Increase in respiratory rate	stimulated
bronchodilation	inhibited
Increase in blood pressure	stimulated
Decreased motility/secretion of the digestive system	inhibited
Contraction of the internal rectal sphincter	stimulated
Relaxation of the smooth muscles of the bladder	inhibited
Contraction of the internal urethral sphincter	stimulated
Stimulation of lipid breakdown (lipolysis)	stimulated
Stimulation of glycogen breakdown	stimulated

Understanding the 3 factors (fear, fight or flight) can help you imagine the answer you can expect. For example, when you are faced with a threatening situation, it makes sense that your heart rate and blood pressure will rise, glycogen breakdown will occur (to provide needed energy), and your breathing rate will increase. All these are stimulating effects. On the other hand, if you are faced with a threatening situation, digestion will not be a priority, so this function is suppressed (inhibited).

Response to cholinergic stimulation

It is useful to remember that parasympathetic stimulation is the opposite of the effect of sympathetic stimulation (at least on organs that have dual innervation - but there are always exceptions to every rule). An example of an exception is the parasympathetic fibers that innervate the heart - inhibition causes the heart rate to slow down.

Additional actions for both sections

The salivary glands are under the influence of the sympathetic and parasympathetic divisions of the ANS. The sympathetic nerves stimulate the constriction of blood vessels throughout the gastrointestinal tract, resulting in reduced blood flow to the salivary glands, which in turn cause thicker saliva. Parasympathetic nerves stimulate the secretion of watery saliva. Thus, the two departments operate in different ways, but basically complement each other.

Combined impact of both departments

Cooperation between the sympathetic and parasympathetic divisions of the ANS can best be seen in the urinary and reproductive systems:

reproductive system sympathetic fiber stimulates sperm ejaculation and reflex peristalsis in women; parasympathetic fibers cause vasodilation, ultimately leading to an erection of the penis in men and the clitoris in women
urinary system sympathetic fiber stimulates the urinary urge reflex by increasing the tone of the bladder; parasympathetic nerves promote bladder contraction

Organs without dual innervation

Most organs of the body are innervated by nerve fibers from both the sympathetic and parasympathetic nervous systems. There are a few exceptions:

Adrenal medulla
sweat glands
(arrector Pili) muscle that raises the hair
most blood vessels

These organs/tissues are only innervated by sympathetic fibers. How does the body regulate their actions? The body achieves control through an increase or decrease in the tone of the sympathetic fibers (the rate of excitation). By controlling the stimulation of sympathetic fibers, the action of these organs can be regulated.

Stress and ANS

When a person is in a threatening situation, messages from sensory nerves are carried to the cerebral cortex and limbic system (the "emotional" brain), as well as to the hypothalamus. The anterior part of the hypothalamus stimulates the sympathetic nervous system. The medulla oblongata contains centers that control many functions of the digestive, cardiovascular, pulmonary, reproductive, and urinary systems. The vagus nerve (which has sensory and motor fibers) provides sensory input to these centers through its afferent fibers. The medulla oblongata itself is regulated by the hypothalamus, the cerebral cortex, and the limbic system. Thus, there are several areas involved in the body's response to stress.
When a person is exposed to extreme stress (a terrifying situation that happens without warning, such as the sight of a wild animal about to attack you), the sympathetic nervous system can become completely paralyzed so that its functions cease completely. The person may freeze in place and be unable to move. May lose control of his bladder. This is due to the overwhelming number of signals that the brain has to "sort" and the corresponding huge surge of adrenaline. Fortunately, most of the time we are not subjected to stress of this magnitude and our autonomic nervous system functions as it should!

Obvious Impairments Related to Autonomic Participation

There are numerous diseases/conditions that are the result of dysfunction of the autonomic nervous system:

orthostatic hypotension- symptoms include dizziness/lightheadedness with position changes (i.e. going from sitting to standing), fainting, visual disturbances, and sometimes nausea. It is sometimes caused with a failure of the baroreceptors to sense and respond to low blood pressure caused by pooling of blood in the legs.

Horner's syndrome Symptoms include decreased sweating, drooping of the eyelids, and constriction of the pupil, affecting one side of the face. This is due to the fact that the sympathetic nerves that pass to the eyes and face are damaged.

Disease– Hirschsprung is called congenital megacolon, this disorder has an enlarged colon and severe constipation. This is due to the absence of parasympathetic ganglia in the colon wall.

Vasovagal syncope– a common cause of fainting, vasovagal syncope occurs when the ANS responds abnormally to a trigger (anxious stares, straining to have a bowel movement, standing for long periods of time) by slowing the heart rate and dilating the blood vessels in the legs, allowing blood to pool in the lower extremities, which leads to a rapid drop in blood pressure.

Raynaud phenomenon This disorder often affects young women, resulting in changes in the color of the fingers and toes, and sometimes the ears and other areas of the body. This is due to extreme vasoconstriction of the peripheral blood vessels as a result of hyperactivation of the sympathetic nervous system. This often occurs due to stress and cold.

spinal shock Caused by severe trauma or injury to the spinal cord, spinal shock can cause autonomic dysreflexia characterized by sweating, severe hypertension, and loss of bowel or bladder control as a result of sympathetic stimulation below the level of spinal cord injury, which is not detected by the parasympathetic nervous system.

Autonomic Neuropathy

Autonomic neuropathies are a set of conditions or diseases that affect sympathetic or parasympathetic neurons (or sometimes both). They can be hereditary (from birth and passed down from affected parents) or acquired at a later age.
The autonomic nervous system controls many bodily functions, so autonomic neuropathies can lead to a range of symptoms and signs that can be detected through a physical examination or laboratory tests. Sometimes only one ANS nerve is affected, however, physicians should watch for symptoms due to involvement in other areas of the ANS. Autonomic neuropathy can cause a wide variety of clinical symptoms. These symptoms depend on the ANS nerves that are affected.

Symptoms can be variable and can affect almost every system in the body:

Integumentary system - pale skin, inability to sweat, affect one side of the face, itching, hyperalgesia (skin hypersensitivity), dry skin, cold feet, brittle nails, worsening of symptoms at night, lack of hair growth on the legs

Cardiovascular system - flutter (interruptions or missed beats), tremor, blurred vision, dizziness, shortness of breath, chest pain, ringing in the ears, discomfort in the lower extremities, fainting.

Gastrointestinal tract - diarrhea or constipation, feeling full after eating small amounts (early satiety), difficulty swallowing, urinary incontinence, decreased salivation, gastric paresis, fainting while using the toilet, increased gastric motility, vomiting (associated with gastroparesis) .

Genitourinary system - erectile dysfunction, inability to ejaculate, inability to achieve orgasm (in women and men), retrograde ejaculation, frequent urination, urinary retention (bladder overflow), urinary incontinence (stress or urinary incontinence), nocturia, enuresis, incomplete emptying of the bladder bubble.

Respiratory system - decreased response to a cholinergic stimulus (bronchostenosis), impaired response to low blood oxygen levels (heart rate and gas exchange efficiency)

Nervous system - burning in the legs, inability to regulate body temperature

Vision system - Blurred/aging vision, photophobia, tubular vision, decreased tearing, focusing difficulties, loss of papillae over time

Causes of autonomic neuropathy can be associated with numerous diseases/conditions after the use of drugs used to treat other diseases or procedures (eg, surgery):

Alcoholism - chronic exposure to ethanol (alcohol) can lead to disruption of axonal transport and damage to the properties of the cytoskeleton. Alcohol has been shown to be toxic to peripheral and autonomic nerves.

Amyloidosis - in this state, insoluble proteins are deposited in various tissues and organs; autonomic dysfunction is common in early hereditary amyloidosis.

Autoimmune diseases - acute intermittent and non-persistent porphyria, Holmes-Adie syndrome, Ross syndrome, multiple myeloma and POTS (Postural Orthostatic Tachycardia Syndrome) are all examples of diseases that have a putative cause of an autoimmune component. The immune system misidentifies body tissues as foreign and attempts to destroy them, resulting in extensive nerve damage.

Diabetic neuropathy usually occurs in diabetes, affecting both sensory and motor nerves, diabetes being the most common cause of LN.

Multiple system atrophy is a neurological disorder that causes degeneration of nerve cells, resulting in changes in autonomic function and problems with movement and balance.

Nerve damage – nerves can be damaged by trauma or surgery, resulting in autonomic dysfunction

Medications – Drugs used therapeutically to treat various conditions can affect the ANS. Below are some examples:

Drugs that increase the activity of the sympathetic nervous system (sympathomimetics): amphetamines, monoamine oxidase inhibitors (antidepressants), beta-adrenergic stimulants.
Drugs that reduce the activity of the sympathetic nervous system (sympatholytics): alpha and beta blockers (i.e. metoprolol), barbiturates, anesthetics.
Drugs that increase parasympathetic activity (parasympathomimetics): anticholinesterase, cholinomimetics, reversible carbamate inhibitors.
Drugs that reduce parasympathetic activity (parasympatholytics): anticholinergics, tranquilizers, antidepressants.

Obviously, people cannot control their several risk factors that contribute to autonomic neuropathy (i.e., hereditary causes of VN.). Diabetes is by far the largest contributor to VL. and puts people with the disease at high risk for VL. Diabetics can reduce their risk of developing LN by carefully monitoring their blood sugar to prevent nerve damage. Smoking, regular alcohol consumption, hypertension, hypercholesterolemia (high blood cholesterol) and obesity can also increase the risk of developing it, so these factors should be controlled as much as possible to reduce the risk.

Treatment of autonomic dysfunction largely depends on the cause of LN. When treatment for the underlying cause is not possible, doctors will try a variety of treatments to alleviate symptoms:

Integumentary system - itching (pruritis) can be treated with medication or you can moisturize the skin, dryness can be the main cause of itching; skin hyperalgesia can be treated with medications such as gabapentin, a drug used to treat neuropathy and nerve pain.

Cardiovascular system - symptoms of orthostatic hypotension can be improved by wearing compression stockings, increasing fluid intake, increasing salt in the diet, and drugs that regulate blood pressure (ie fludrocortisone). Tachycardia can be controlled with beta-blockers. Patients should be counseled to avoid sudden changes in condition.

Gastrointestinal system - Patients may be advised to eat often and in small portions if they have gastroparesis. Medications can sometimes be helpful in increasing mobility (ie Raglan). Increasing fiber in your diet can help with constipation. Bowel retraining is also sometimes helpful for treating bowel problems. Antidepressants sometimes help with diarrhea. A diet low in fat and high in fiber can improve digestion and constipation. Diabetics should strive to normalize their blood sugar.

Genitourinary – Bladder training, overactive bladder medications, intermittent catheterization (used to completely empty the bladder when incomplete emptying of the bladder is a problem) and erectile dysfunction medications (i.e., Viagra) may be used to treat sexual problems.

Vision issues – Medications are sometimes prescribed to reduce vision loss.

The central nervous system of a person exercises control over the activities of his body and is divided into several departments. The brain sends and receives signals from the body and, after processing them, has information about the processes. The nervous system is divided into autonomic and somatic nervous systems.

Differences between the autonomic and somatic nervous systems

somatic nervous system regulated by human consciousness and can control the activity of skeletal muscles. All components of a person's reaction to external factors are under the control of the cerebral hemispheres. It provides sensory and motor reactions of a person, controlling their excitation and inhibition.

autonomic nervous system controls the peripheral activity of the body and is not controlled by consciousness. It is characterized by autonomy and generalized effects on the body in the complete absence of consciousness. The efferent innervation of the internal organs allows it to control the metabolic processes in the body and to ensure the trophic processes of the skeletal muscles, receptors, skin and internal organs.

The structure of the vegetative system

The work of the autonomic nervous system is controlled by the hypothalamus, which is located in the central nervous system. The autonomic nervous system has a metasegmental structure. Its centers are in the brain, spinal cord and cerebral cortex. Peripheral sections are formed by trunks, ganglia, plexuses.

In the autonomic nervous system, there are:

• Sympathetic. Its center is located in the thoracolumbar region of the spinal cord. It is characterized by paravertebral and prevertebral ganglia of the ANS.
• Parasympathetic. Its centers are concentrated in the middle and medulla oblongata, sacral spinal cord. mostly intramural.
• Metasympathetic. Innervates the gastrointestinal tract, blood vessels, internal organs of the body.

It includes:

1. Nuclei of nerve centers located in the brain and spinal cord.
2. Vegetative ganglia, which are located on the periphery.

Reflex arc of the autonomic nervous system

The reflex arc of the autonomic nervous system consists of three links:

• sensitive or afferent;
• intercalary or associative;
• effector.

Their interaction is carried out without the participation of additional intercalary neurons, as in the reflex arc of the central nervous system.

sensitive link

The sensory link is located in the spinal ganglion. This ganglion has nerve cells formed in groups, and their control is exercised by the nuclei of the central brain, the cerebral hemispheres and their structures.

The sensitive link is represented by partially unipolar cells that have one incoming or outgoing axon, and they belong to the spinal or cranial nodes. As well as nodes of the vagus nerves, which have a structure similar to spinal cells. This link includes type II Dogel cells, which are components of the autonomic ganglia.

insert link

The intercalary link in the autonomic nervous system serves to transmit through the lower nerve centers, which are the autonomic ganglia, and this is done through synapses. It is located in the lateral horns of the spinal cord. There is no direct connection from the afferent link to the preganglionic neurons for their connection, there is the shortest path from the afferent neuron to the associative and from it to the preganglionic neuron. Transmission of signals and from afferent neurons in different centers is carried out with a different number of intercalary neurons.

For example, in the arc of the spinal autonomic reflex between the sensory and effector link, there are three synapses, two of which are located in and one in the vegetative node, in which the efferent neuron is located.

Efferent link

The efferent link is represented by effector neurons, which are located in the vegetative nodes. Their axons form non-myelinated fibers, which, together with mixed nerve fibers, innervate the internal organs.

The arcs are located in the lateral horns.

The structure of the nerve node

A ganglion is an accumulation of nerve cells that look like nodular extensions about 10 mm thick. In its structure, the vegetative ganglion is covered on top with a connective tissue capsule, which forms a stroma of loose connective tissue inside the organs. Multipolar neurons, which are built from a rounded nucleus and large nucleoli, consist of one efferent neuron and several divergent afferent neurons. These cells are similar in type to brain cells and are motor. They are surrounded by a loose shell - the mantle glia, which creates a constant environment for the nervous tissue and ensures the full functioning of the nerve cells.

The autonomic ganglion has a diffuse arrangement of nerve cells and many processes, dendrites, and axons.

The spinal ganglion has nerve cells that are arranged in groups, and their arrangement is conditioned.

Autonomic nerve ganglia are divided into:

• Sensory neurons that are located close to the dorsal or central region of the brain. The unipolar neurons that make up this ganglion are an afferent or afferent process. They serve for afferent transmission of impulses, and their neurons form a bifurcation during the branching of processes. These processes transmit information from the periphery to the central afferent neuron - this is the peripheral process, the central one - from the body of the neuron to the brain center.
• consist of efferent neurons, and depending on their position they are called paravertebral, prevertebral.

Sympathetic ganglia

Paravertebral chains of ganglia are located along the spinal column in sympathetic trunks, which run in a long line from the base of the skull to the coccyx.

The prevertebral nerve plexuses are closer to the internal organs, and their localization is concentrated in front of the aorta. They form the abdominal plexus, which consists of the solar, inferior and superior mesenteric plexuses. They are represented by motor adrenergic and inhibitory cholinergic neurons. Also, the connection between neurons is carried out by preganglionic and postganglionic neurons, which use the mediators acetylcholine and norepinephrine.

Intramural ganglions have three types of neurons. Their description was made by the Russian scientist Dogel A.S., who, studying the histology of neurons of the autonomic nervous system, identified such neurons as long-axon efferent cells of the first type, equal-length afferent cells of the second type and associative cells of the third type.

Ganglion receptors

Afferent neurons perform a highly specialized function, and their role is to perceive stimuli. Such receptors are mechanoreceptors (response to stretching or pressure), photoreceptors, thermoreceptors, chemoreceptors (responsible for reactions in the body, chemical bonds), nociceptors (the body's response to pain stimuli is skin damage and others).

In the sympathetic trunks, these receptors transmit information through a reflex arc to the central nervous system, which serves as a signal of damage or disturbances in the body, as well as its normal functioning.

Functions of the ganglia

Each ganglion has its own location, blood supply, and its functions are determined by these parameters. The spinal ganglion, which has innervation from the nuclei of the brain, provides a direct connection between the processes in the body through a reflex arc. From these structural components of the spinal cord, the glands, the smooth muscles of the muscles of the internal organs, are innervated. The signals coming through the reflex arc are slower than in the central nervous system, and they are fully regulated by the autonomic system, it also has a trophic, vasomotor function.

In order for the body to receive the energy it needs, a whole complex of complex chemical reactions is necessary - this process is called fat or lipid metabolism. If it is disturbed, fats are either misused or stored in excess, which leads to the development of a variety of diseases. One of the most common is atherosclerosis. Beta lipoproteins or beta lipoproteins are substances that are essential in the development of this dangerous disease.

Why are lipoproteins needed?

In human blood plasma, among other components, there are several types of fats and fat-like elements. But they are not in free form, but are always associated with a carrier protein - apoprotein. Such compounds are called lipoproteins. They are susceptible to dissolution in water, and therefore can move freely along with the bloodstream throughout the body. What does it mean?

Fat cells can be in the composition of such compounds:

1. Chylomicrons are the largest elements of fat, they consist of triglycerides, cholesterol, a small amount of protein and phospholipids. They are synthesized in the small intestine after the digestion of food rich in fats. Then they enter the bloodstream, are transferred to the liver, where its cells carry out subsequent processing and transformation. Chylomicrons do not have atherogenic properties - in other words, they do not cause atherosclerosis. This is due to their large size - this does not allow them to penetrate through the membranes of vascular cells.
2. Prebeta, into lipoproteins are low and very low density lipoproteins. They usually provoke the development of atherosclerosis. They contain up to 45% cholesterol, they are small in size and can penetrate into vascular cells. They carry particles of fat to various cells and organs. In a way, these are energy suppliers for them, but if some metabolic processes are disturbed, they become a factor provoking atherosclerosis.

If there are too many lipoproteins in the blood, they are deposited on the walls of blood vessels in the form of loose fatty deposits. Then the deposits thicken, begin to grow and block the lumen of the vessel - partially or completely. This is how an atherosclerotic plaque is formed - a pathology that leads to a variety of complications from the heart and blood vessels, significantly worsen a person's well-being and even cause his death. The number of plaques is not calculated in units, there can be a lot of them. To reduce the risk of atherosclerosis, reduce the intake of animal fats.

There are also alpha lipoproteins. Of all the fat particles, they are the smallest and differ in a board-like shape. They are synthesized by the liver, then they enter the bloodstream, where they begin to attract particles of fat from all surfaces. When alpha lipoprotein is completely filled with fat molecules, its shape becomes spherical. After that, it returns to the liver again and is transformed into other substances. These are high-density lipoproteins, they do no harm to blood vessels and are often referred to as good cholesterol. But if, according to the results of the analyzes, they are reduced, the best consequences should not be expected.

Who needs to be tested

An increase in the level of beta and prebet lipoproteins are the main prerequisites for the formation of an atherosclerotic plaque. If the patient has a predisposition to atherosclerosis or a tendency to pathologies of the heart and blood vessels, then he should regularly monitor the level of these substances in the blood.

A blood test for the content of beta lipoproteins is recommended in such cases:

1. If, during a planned or random examination of a patient, an increased concentration of cholesterol in the blood plasma was established. To get a complete picture of how lipid metabolism proceeds in the body of a patient, an analysis of the lipid spectrum is prescribed. After receiving the results of the study, the doctor will recommend the necessary measures to adjust the diet, lifestyle, and, if necessary, prescribe certain medications.
2. If the patient has already been diagnosed with angina pectoris, coronary heart disease, or has suffered a myocardial infarction.
3. If there was an acute violation of blood circulation in the brain - a stroke.
4. If the patient has pathologically high blood pressure - myocardial infarction.

Also, this analysis to control a person’s condition can be prescribed to those who are at risk or have a genetic predisposition to pathologies of the heart and blood vessels. The risk group includes people over forty years of age, anyone who is obese or diabetic, regularly drinks alcohol or smokes.

Donating blood for beta lipoproteins and total blood cholesterol is recommended for everyone once every five years after reaching the age of 25.

Such a measure allows you to identify possible deviations in time and prevent the development of a serious pathology. In this case, it will be enough just to adjust the diet and determine moderate physical activity. If a person is at risk, then he needs to take such an analysis at least once every twelve months.

Preparation for analysis

It is very important to properly prepare for blood sampling for this study, otherwise you can get a distorted picture and miss the beginning of the development of a disease. The fact is that the level of beta lipoproteins can change under the influence of a variety of factors, and they do not always indicate the presence of pathology. Increase the concentration of these compounds:

1. Pregnancy. When a woman carries a child, the level of beta lipoproteins in her blood plasma increases by 1.5-2 times. Indicators return to normal a few weeks after childbirth. If this does not happen, the patient will need additional examination and, probably, appropriate treatment. During pregnancy, elevated levels of lipoproteins are a normal physiological phenomenon.
2. Smoking - the intake of nicotine in the body changes the composition of the blood.
3. If the blood was taken when the person was standing.
4. Taking hormone-containing drugs, anabolics.

There are also factors that, on the contrary, can lower the level of beta lipoproteins in the blood and thereby violate the reliability of the analysis. These include:

1. Physical activity before blood sampling.
2. Horizontal position during the procedure.
3. Strict diet, malnutrition.
4. Taking certain drugs, in particular, antifungal agents or those containing estrogen, colchicines, statins.

That is why it is so important to properly prepare for the analysis and not violate the doctor's recommendations - usually such a study is carried out in a planned manner, and the doctor gives all the necessary instructions. The preparation is as follows:

• for two weeks before the analysis, it is recommended not to deviate from the usual way of life, to adhere to the previous diet in order to get a reliable picture of what is happening in the body;
• an analysis for beta lipoproteins is not given if a person has recently had a serious illness;
• Do not eat anything immediately before blood sampling. The last meal should be no later than eight hours before the analysis;
• You need to donate blood in the morning only on an empty stomach. Do not drink tea, coffee, juice or water with gas;
• do not smoke at least half an hour before blood sampling;
• before the analysis, you need to sit quietly for a few minutes. Blood is given strictly in a sitting position, it is taken from a vein.

Of course, no one is immune from the oversight of a laboratory assistant who will examine biological raw materials. But medical errors are extremely rare. And proper preparation for analysis minimizes the likelihood of distorting the picture. The study itself is carried out using photometric and colorimetric methods, you can get the results in a day.

Blood lipoproteins are measured in millimoles per liter. If the analysis shows deviations from the norm, the patient will be referred for consultation and examination to narrow specialists - a neuropathologist, cardiologist, endocrinologist.

Norms for men and women

Metabolic processes in the female and male organisms proceed differently. That is why in medicine there are pathologies that are considered “male” or “female”. Young women are very rarely diagnosed with atherosclerosis. This is due to the active production of the hormone estrogen - it reliably protects the woman's vessels from accumulations of harmful cholesterol. The male hormone is not able to protect blood vessels, so you need to take tests more often, lowering cholesterol levels if it is elevated.

With age, estrogen production decreases, and after the onset of menopause it stops altogether. Therefore, after 40-45 years, both men and women are equally at risk of getting any diseases of the cardiovascular system and their accompanying complications.

The indicators will vary not only depending on the gender, but also the age of the patient. The content of lipoproteins of very low density and low density is estimated. The first is a combination of fats and proteins, which has the shape of a sphere. They contain mainly cholesterol and are the main provocateurs of atherosclerosis. If there are a lot of them, cholesterol plaques begin to form on the walls of blood vessels. Here are the standards set for the content of this substance:

1. Age up to 19 years - for men from 1.54 to 3.60 mmol / liter, for women from 1.54 to 3.87 mmol / liter.
2. From 20 to 30 years - for men from 1.52 to 4.49 mmol / liter and for women from 1.54 to 4.12 mmol / liter.
3. From 31 to 40 years - for men from 2.09 to 4.91 mmol / liter and for women from 1.84 to 4.35 mmol / liter.
4. From 41 to 50 years - for men from 2.30 to 5.32 mmol / liter, for women from 2.04 to 4.90 mmol / liter.
5. From 51 to 60 years - for men from 2.31 to 5.30 mmol / liter and for women from 2.30 to 5.64 mmol / liter.
6. From 61 to 70 years - for men from 2.31 to 5.56 mmol / liter and for women from 2.44 to 5.54 mmol / liter.

The established norms for the level of very low density lipoproteins are the same for both males and females. Indicators vary from 0.1 to 1.4 mmol / liter. At the same time, medicine has not yet established exactly what function this fraction performs in the human body. If low density lipoproteins directly affect the formation of cholesterol plaques and the development of atherosclerosis, then very low density lipoproteins do not have this property.

It is believed that these compounds initially belong to the harmful decay products after fat metabolism and the body does not need them. A number of studies confirm this assumption. That is why there are no clearly established norms for the content of very low density lipoproteins in human blood. Their decrease or increase usually does not affect the overall clinical picture of the disease and the patient's well-being.

Why is the level rising?

A similar phenomenon is not uncommon in the results of analyzes of people whose age exceeds 40-50 years. How can it be explained, what factors influence the change in the content of these substances in human blood?

1. Stagnation of bile in the liver or bile ducts in pathologies such as hepatitis, cirrhosis, cholecystitis, tumors of various nature.
2. Kidney dysfunction leading to kidney failure.
3. Diseases of the endocrine system, in particular, hypothyroidism.
4. Sugar disease of uncompensated form.
5. Metabolic disorder, obesity.
6. Alcohol abuse.
7. Oncological diseases of the pancreas or prostate.
8. Unbalanced diet with a predominance of fatty foods.

Beta lipoproteins are deposited on the walls of blood vessels gradually. Therefore, a person may not have any complaints at all for a long time.

But when their concentration becomes too high, the first symptoms of atherosclerosis begin to appear:

• with rare exceptions, weight gain;
• the appearance of wen on the body and face. These are small seals under the skin, filled with cholesterol, they are localized along the lines of the tendons. In medicine, such formations are called xanthomas and xanthelases;
• aching pain behind the sternum is a symptom of developing coronary heart disease and angina pectoris. Unpleasant sensations can be given to the neck, shoulder, arms, at first they are easy to remove if you take nitroglycerin preparations. But with the progression of the disease, the pain becomes more frequent, the attacks become longer and are poorly suppressed by medications;
• forgetfulness, absent-mindedness, decreased performance;
• numbness of the lower extremities, a change in gait - this indicates that there is a lesion of the vessels responsible for the blood supply to the legs.

If there is a significant proliferation of atherosclerotic plaques, leading to a narrowing of the vascular lumens, life-threatening complications such as myocardial infarction or stroke can develop.

What is an acute myocardial infarction? if insufficient blood is supplied to the heart muscle along with all the necessary substances, its cells gradually die off. This is an irreversible process. If measures are not taken in time, complete necrosis of the tissues of a certain area of ​​​​the heart muscle occurs - this is what is called myocardial infarction. Pathology develops rapidly, sometimes within a few minutes. At first, a person experiences a sharp, sharp pain behind the sternum, which does not allow to move or take a deep breath. Nitroglycerin does not help with these symptoms. It is necessary to lay the patient horizontally with a raised head, provide access to fresh air and immediately call an ambulance.

A stroke occurs when there is an acute violation of intracerebral circulation. Brain tissues begin to die for the same reason - an acute deficiency of oxygen and nutrients. Stroke can manifest itself in different ways:

• partial paralysis of the limbs or one half of the face;
• speech disorders;
• pelvic dysfunction - involuntary urination and defecation.

In this case, the threat to the life of the patient is also very high, so he needs urgent hospitalization.

Such complications can be avoided if complex treatment is carried out in time, aimed at reducing the level of beta lipoproteins in the blood. It consists of the following activities:

1. Eating a diet low in fat and simple carbohydrates.
2. Complete cessation of smoking and alcohol.
3. Feasible physical activity - sports such as swimming, walking, yoga, Pilates are suitable.

You can not do without medication. To reduce cholesterol in the body, combinations of statins, sequestrants and fibrates are used, they must be taken to obtain a tangible result for at least three months. Accordingly, every three months the patient takes a control blood test for the content of lipoproteins in order to track the dynamics of the disease and evaluate the effectiveness of the ongoing drug therapy. All appointments are made only by a doctor, who also adjusts the treatment regimen based on the results of the tests and the general condition of the patient.

Decrease in beta lipoproteins in the blood test

This phenomenon is much less common and does not have significant significance in the diagnosis of certain diseases. The following pathologies and conditions can provoke a decrease in the level of lipoproteins in the blood:

• genetic predisposition;
• severe decompensated liver failure;
• oncological diseases of the bone marrow;
• severe burns;
• hyperthyroidism;
• arthritis of an autoimmune nature, various arthrosis;
• infectious diseases in the acute stage;
• bronchial asthma.

Treatment should be aimed at eliminating the underlying disease, no special medications are needed to increase the level of beta lipoproteins and lipoprotein fractions in order to normalize their normal rate.

The level of lipoproteins in the blood is important for the normal functioning of the body. At the same time, few people know that not only an increase, but also a decrease in blood cholesterol can cause harm. Today we will analyze what kind of substance it is, as well as what threatens to violate the norms of cholesterol in the blood. Learn what to do if β-lipoproteins are lowered. Let's talk about the most common medicinal and folk methods of regulation in the blood.

Cholesterol is lipoproteins, some of which are synthesized directly in the body (80%), and some comes from food (20%). They are insoluble in water, but highly soluble in fats. Transportation of cholesterol is carried out through the vessels.

So what are the types:

1. High-density lipoproteins (or α-lipoproteins) - the so-called "good" cholesterol. This substance helps to control the level of LDL and VLDL in the blood. HDL capture molecules of "bad" cholesterol and transfer them for further processing to the liver. After which they are excreted from the body.
2. Low-density lipoproteins (or β-lipoproteins), popularly called "bad" cholesterol. In fact, it is this substance that affects many life processes. LDL is part of cell membranes, making them more elastic. The substance affects the synthesis of hormones (for example, testosterone) and vitamins of group D. But, it is worth remembering that with an excess of LDL, the likelihood of cholesterol plaques is high.
3. Very low density lipoproteins - the density of this substance is even lower than that of LDL. This is another important factor influencing the development of atherosclerosis, and as a consequence of diseases of the cardiovascular system.
4. Chomicrons are a lipid substance composed of 87% triglycerides, 5% cholesterol, 2% protein, plus phospholipids. Their size is quite large - 75 nm.

Lipoproteins are complex protein-lipid complexes that are part of all living organisms and are a necessary part of cellular structures. Lipoproteins perform a transport function. Their content in the blood is an important diagnostic test, signaling the degree of development of diseases of the body systems.

This is a class of complex molecules, which can simultaneously include free, fatty acids, neutral fats, phospholipids and in various quantitative ratios.

Lipoproteins deliver lipids to various tissues and organs. They consist of non-polar fats located in the central part of the molecule - the core, which is surrounded by a shell formed from polar lipids and apoproteins. The similar structure of lipoproteins explains their amphiphilic properties: simultaneous hydrophilicity and hydrophobicity of the substance.

Functions and meaning

Lipids play an important role in the human body. They are found in all cells and tissues and are involved in many metabolic processes.

lipoprotein structure

• Lipoproteins are the main transport form of lipids in the body.. Since lipids are insoluble compounds, they cannot fulfill their purpose on their own. Lipids bind in the blood to proteins - apoproteins, become soluble and form a new substance called lipoprotein or lipoprotein. These two names are equivalent, abbreviated - LP.

Lipoproteins occupy a key position in the transport and metabolism of lipids. Chylomicrons transport fats that enter the body with food, VLDL deliver endogenous triglycerides to the site of disposal, cholesterol enters cells with the help of LDL, HDL have antiatherogenic properties.

• Lipoproteins increase the permeability of cell membranes.
• LP, the protein part of which is represented by globulins, stimulate the immune system, activate the blood coagulation system and deliver iron to the tissues.

Classification

LP of blood plasma is classified by density(using the ultracentrifugation method). The more lipids are contained in the LP molecule, the lower their density. Allocate VLDL, LDL, HDL, chylomicrons. This is the most accurate of all existing drug classifications, which was developed and proven using an accurate and rather painstaking method - ultracentrifugation.

The size of the LP is also heterogeneous. The largest molecules are chylomicrons, and then in decreasing size - VLDL, HDL, LDL, HDL.

Electrophoretic classification LP is very popular among clinicians. Using electrophoresis, the following classes of LP were identified: chylomicrons, pre-beta lipoproteins, beta lipoproteins, alpha lipoproteins. This method is based on the introduction of an active substance into a liquid medium using a galvanic current.

Fractionation LP is carried out in order to determine their concentration in blood plasma. VLDL and LDL are precipitated with heparin, while HDL remains in the supernatant.

Kinds

Currently, the following types of lipoproteins are distinguished:

HDL (high density lipoprotein)

HDL transports cholesterol from body tissues to the liver.

1. An increase in HDL in the blood is noted with obesity, fatty hepatosis and biliary cirrhosis, alcohol intoxication.
2. A decrease in HDL occurs with hereditary Tangier disease, caused by the accumulation of cholesterol in tissues. In most other cases, a decrease in the concentration of HDL in the blood is a sign.

HDL levels are different for men and women. In males, the LP value of this class ranges from 0.78 to 1.81 mmol / l, the norm for women HDL is from 0.78 to 2.20, depending on age.

LDL (low density lipoprotein)

LDL are carriers of endogenous cholesterol, triglycerides and phospholipids from the liver to tissues.

This class of LP contains up to 45% cholesterol and is its transport form in the blood. LDL is formed in the blood as a result of the action of the enzyme lipoprotein lipase on VLDL. With its excess, they appear on the walls of the vessels.

Normally, the amount of LDL is 1.3-3.5 mmol / l.

• The level of LDL in the blood rises with hypothyroidism, nephrotic syndrome.
• A reduced level of LDL is observed with inflammation of the pancreas, hepatic-renal pathology, acute infectious processes, pregnancy.

infographics (click to enlarge) - cholesterol and LP, role in the body and norms

VLDL (very low density lipoproteins)

VLDL are formed in the liver. They carry endogenous lipids synthesized in the liver from carbohydrates into tissues.

These are the largest LPs, second in size only to chylomicrons. They are more than half made up of triglycerides and contain a small amount of cholesterol. With an excess of VLDL, the blood becomes cloudy and acquires a milky hue.

VLDL is a source of "bad" cholesterol, from which plaques form on the vascular endothelium. Gradually plaques increase, joins with the risk of acute ischemia. VLDL is elevated in patients with kidney disease.

Chylomicrons

Chylomicrons are absent in the blood of a healthy person and appear only in violation of lipid metabolism. Chylomicrons are synthesized in the epithelial cells of the small intestine mucosa. They deliver exogenous fat from the intestine to peripheral tissues and the liver. Most of the transported fats are triglycerides, as well as phospholipids and cholesterol. In the liver, under the influence of enzymes, triglycerides break down and fatty acids are formed, some of which are transported to muscles and adipose tissue, and the other part binds to blood albumins.

what do major lipoproteins look like

LDL and VLDL are highly atherogenic- containing a lot of cholesterol. They penetrate the wall of the arteries and accumulate in it. When metabolism is disturbed, the level of LDL and cholesterol rises sharply.

The most safe against atherosclerosis are HDL. Lipoproteins of this class remove cholesterol from cells and contribute to its entry into the liver. From there, it enters the intestines with bile and leaves the body.

Representatives of all other classes of LP deliver cholesterol to cells. Cholesterol is a lipoprotein that is part of the cell wall. It is involved in the formation of sex hormones, the process of bile formation, the synthesis of vitamin D, which is necessary for the absorption of calcium. Endogenous cholesterol is synthesized in the liver tissue, adrenal cells, intestinal walls, and even in the skin. Exogenous cholesterol enters the body along with animal products.

Dyslipoproteinemia - a diagnosis in violation of lipoprotein metabolism

Dyslipoproteinemia develops when two processes are disturbed in the human body: the formation of LP and the rate of their excretion from the blood. H violation of the ratio of LP in the blood is not a pathology, but a factor in the development of a chronic disease, in which the arterial walls are compacted, their lumen narrows and the blood supply to the internal organs is disturbed.

With an increase in the level of cholesterol in the blood and a decrease in the level of HDL, atherosclerosis develops, leading to development of deadly diseases.

Etiology

Primary dyslipoproteinemia is genetically determined.

Causes secondary dyslipoproteinemias are:

1. hypodynamia,
2. Diabetes,
3. Alcoholism,
4. kidney dysfunction,
5. hypothyroidism,
6. hepatic-renal failure,
7. Long-term use of certain medications.

The concept of dyslipoproteinemia includes 3 processes - hyperlipoproteinemia, hypolipoproteinemia, alipoproteinemia. Dyslipoproteinemia is quite common: every second inhabitant of the planet has similar changes in the blood.

Hyperlipoproteinemia is an increased content of LP in the blood due to exogenous and endogenous causes. The secondary form of hyperlipoproteinemia develops against the background of the underlying pathology. In autoimmune diseases, LP are perceived by the body as antigens, to which antibodies are produced. As a result, antigen-antibody complexes are formed, which are more atherogenic than the drugs themselves.

Alipoproteinemia is a genetically determined disease with autosomal dominant inheritance. The disease is manifested by an increase in the tonsils with an orange coating, hepatosplenomegaly, lymphadenitis, muscle weakness, decreased reflexes, and hyposensitivity.

Hypolipoproteinemia – low blood levels of lipoproteins, often asymptomatic. The causes of the disease are:

1. Heredity,
2. malnutrition,
3. Passive lifestyle,
4. Alcoholism,
5. Pathology of the digestive system,
6. Endocrinopathy.

Dyslipoproteinemias are: organ or regulatory , toxigenic, basal - a study of the level of LP on an empty stomach, induced - a study of the level of LP after a meal, drugs or exercise.

Diagnostics

It is known that excess cholesterol is very harmful for the human body. But the lack of this substance can lead to dysfunction of organs and systems. The problem lies in hereditary predisposition, as well as in lifestyle and nutritional habits.

Diagnosis of dyslipoproteinemia is based on the history of the disease, complaints of patients, clinical signs - the presence of xanthoma, xanthelasma, lipoid arch of the cornea.

The main diagnostic method of dyslipoproteinemia is a blood test for lipids. Determine the coefficient of atherogenicity and the main indicators of the lipid profile - triglycerides, total cholesterol, HDL, LDL.

Lipidogram is a laboratory diagnostic method that reveals lipid metabolism disorders that lead to the development of diseases of the heart and blood vessels. Lipidogram allows the doctor to assess the patient's condition, determine the risk of developing atherosclerosis of the coronary, cerebral, renal and hepatic vessels, as well as diseases of the internal organs. Blood is taken in the laboratory strictly on an empty stomach, at least 12 hours after the last meal. The day before the analysis exclude the intake of alcohol, and an hour before the study - smoking. On the eve of the analysis, it is desirable to avoid stress and emotional overstrain.

The enzymatic method for studying venous blood is the main one for determining lipids. The device fixes samples previously stained with special reagents. This diagnostic method allows you to conduct mass examinations and obtain accurate results.

It is necessary to take tests to determine the lipid spectrum for prophylactic purposes, starting from adolescence, once every 5 years. Persons over the age of 40 should do this annually. Conduct a blood test in almost every district clinic. Patients suffering from hypertension, obesity, diseases of the heart, liver and kidneys are also prescribed a lipid profile. Burdened heredity, existing risk factors, monitoring the effectiveness of treatment are indications for prescribing a lipid profile.

The results of the study may be unreliable after eating on the eve of food, smoking, stress, acute infection, during pregnancy, taking certain medications.

Diagnosis and treatment of pathology is carried out by an endocrinologist, a cardiologist, a therapist, a general practitioner, a family doctor.

Treatment

plays a huge role in the treatment of dyslipoproteinemia. Patients are advised to limit the intake of animal fats or replace them with synthetic ones, eat up to 5 times a day in small portions. The diet must be enriched with vitamins and dietary fiber. You should give up fatty and fried foods, replace meat with sea fish, eat a lot of vegetables and fruits. Restorative therapy and sufficient physical activity improve the general condition of patients.

figure: useful and harmful “diets” in terms of LP balance

Lipid-lowering therapy and antihyperlipoproteinemic drugs are designed to correct dyslipoproteinemia. They are aimed at lowering the level of cholesterol and LDL in the blood, as well as increasing the level of HDL.

Of the drugs for the treatment of hyperlipoproteinemia, patients are prescribed:

• - Lovastatin, Fluvastatin, Mevacor, Zokor, Lipitor. This group of drugs reduces the production of cholesterol by the liver, reduces the amount of intracellular cholesterol, destroys lipids and has an anti-inflammatory effect.
• Sequestrants reduce the synthesis of cholesterol and remove it from the body - Cholestyramine, Colestipol, Cholestipol, Cholestan.
• I reduce the level of triglycerides and increase the level of HDL - "Fenofibrate", "Ciprofibrat".
• B group vitamins.

Hyperlipoproteinemia requires treatment with hypolipidemic drugs "Cholesteramine", "Nicotinic acid", "Miscleron", "Clofibrate".

Treatment of the secondary form of dyslipoproteinemia is to eliminate the underlying disease. Patients with diabetes are advised to change their lifestyle, regularly take sugar-lowering drugs, as well as statins and fibrates. In severe cases, insulin therapy is required. With hypothyroidism, it is necessary to normalize the function of the thyroid gland. For this, patients undergo hormone replacement therapy.

Patients suffering from dyslipoproteinemia are recommended after the main treatment:

1. Normalize body weight
2. Dose physical activity,
3. Limit or eliminate alcohol consumption
4. Avoid stress and conflict as much as possible
5. Give up smoking.

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