Spinal cord presentation. Presentation in physiology on the topic of the spinal cord. Spinal nerve injury
Lesson Plan Date Grade ____ 8th
Lesson 14 biology
Teacher
Lesson topic: FROM pin brain. Gray and white matter of the spinal cord, central canal. Nerves leaving the spinal cord. The value of the spinal cord, its reflex and conductive functions(slide 1).
Lesson type: combined
The purpose of the lesson: To acquaint students with the features of the structure and functions of the spinal cord.
Lesson objectives.
Educational: expand knowledge about the structure and functions of the nervous system; to form knowledge about the features of the external and internal structure of the spinal cord; consider the functions of the spinal cord;
Developing: continue to develop the ability to think logically, draw conclusions, compare, generalize;
Educational: continue to shape the scientific worldview of students.
Equipment: table "Spinal cord", "Electronic manualin biology. Grade 8 "Volkova T.V. (ISBN978-601-7438-01-2),presentation, flash videos "Brain substances", "Reflex arc of the knee jerk" .
During the classes
Lesson stage
MO
FOPD
Preparation for EAEA, UNT
Tasks for the development of functional literacy
Individual correctional work
I . Org. moment
Organizational and psychological attitude.
Greetings. Preparing the class for work. The presence of students.
Collective
II . Examination
d/z:
BUT). Orally:
1. The role of the nervous system in the human body.
2. What cells form the nervous tissue? What are its properties and meanings?
3. Why a neuron is considered a structural and functional unit of the nervous system.
4. What is the structure of a neuron?
5. List the neurons by function and what is their significance?
6. What is a reflex? What reflexes do you know?
7. List the main links of the reflex arc.
8. What does the somatic nervous system innervate?
9. How does the function of the autonomic nervous system differ from the somatic nervous system?
B). Strategy "Hot chair" over the concepts on the topic "Structure and functions of the nervous system. Reflex and reflex arc"(neuron, axon, dendrites, myelin sheath, nerves, ganglions, neuroglia, synapse, neurotransmitter, nerve impulse, reflex, reflex arc).
AT). Biological tasks (slide 2).
Working in groups, discuss and come to a common solution to the biological problem on the topic “Nervous system:
1 group
A leaf reaches for the light, a worm crawls into the dark, a frog seeks wet places, a dog answers a call, a person withdraws his hand from a hot object. Why?
2 group:
The man was walking barefoot, stepped on a sharp object and his foot immediately pulled back; suddenly the phone rings and you reach out to the handset; when a light is turned on in a dark room, a person closes his eyes;in a dog eating, the sight of a cat causes a cessation of salivation; the newborn firmly grasps any object that falls into his hands.Which of the proposed examples relate to unconditioned reflexes, and which to conditioned? Explain the answer.
3rd group:
A mosquito landed on the sleeping man's face. He pushed the insect away with his hand without waking up. Why and how did such a reaction occur if the hand was at some distance from the face?
4th group:
In newborns (especially premature babies), the Robinson reflex is manifested. The child firmly grasps any object that falls into his hands. Explain the meaning of this reflex. What happens to this reflex in a child in the future and why?
PP
state of emergency
Frontal
Individual
Group work
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III. And learning new material.
The nervous system is formed by the brain and spinal cord, as well as all their branches - nerves and nerve nodes. The nervous system consists of more than ten billion cells, neurons, working together in a coordinated manner.
The oldest and most durable part of the human nervous system isspinal cord.
Today in the lesson you will get acquainted with the structural features and functions of the spinal cord.
BUT). Location of the spinal cord (slide 3).
The spinal cord is a section of the nervous system that originally arose in non-cranial chordates.
Spinal cord located in the spinal canal and in adults it is a long (45 cm in men and 41-42 cm in women) cylindrical cord, weighing 30-40 g and about 1 cm in diameter.Above, it passes into the medulla oblongata, and below, at the levelI- IIlumbar vertebrae, ends.
B). Shells of the brain (slide 4).
The spinal cord is surrounded by three membranes:hard - the most external;gossamer– average, softly aya - the innermost is located inside the solid and is protected by the spine.
Shell functions:
serve to protect the nervous tissue from mechanical damage;
are a barrier that prevents the penetration of microbes and various substances into the brain;
contains blood vessels involved in the secretion of cerebrospinal fluid.
AT). The structure of the spinal cord (slide 5).
On the anterior and posterior sides, the spinal cord has deepanterior and posterior longitudinal grooves. They divide it into right and left parts.
The spinal cord is made up ofwhite matter located at the edges, andgray matter , located in the center and looking like butterfly wings (flash video "Brain Substances".in the gray matter arebodies of nerve cells , ain white - their processes .
Cross section of the spinal cord shows thatnarrow central canal , filledcerebrospinal fluid (120 - 150 ml per day) .
Significance of cerebrospinal fluid (slide 6):
carrying nutrients to the cells of the spinal cord;
shock absorber;
takes part in the removal of metabolic products;
has bactericidal properties;
can be updated up to 6 times a day.
The gray matter of the spinal cord is made up offront, lateral and posterior horns (slide 7).
in the anterior horns gray matter arebodies of motor neurons , axons
which formfront spine.
In the back horns locatedinsertion (intermediate, contact) neurons , which carry out the connection between centripetal and centrifugal neurons.The back spine is formed sensory cell fibers , body which are locatedin spinal cords.
Through the posterior roots, excitation is transmitted from the periphery to the spinal cord - these are sensitive roots. Through the anterior roots, excitation is transmitted from the spinal cord to the muscles and other organs - these are motor roots.
Surrounding the gray matter is white matter, formed by long processes of neurons. They formpathways spinal cord.
departs from the spinal cord31 mixed spinal nerves (8 pairs of cervical, 12 pairs of thoracic, 5 - lumbar, 5 - sacral and 1-2 coccygeal). Each pair of spinal nerves begins with two roots: posterior (axons of sensory neurons) and anterior (axons of motor neurons)(slide 8).
8. Spinal Cord Functions : reflex and conductive(slides 9-11).
1. Conductor
Conducting impulses from organs and tissues;
There is a connection between the spinal cord and the brain.
2 .Reflex (View flash - video "Reflex arc of the knee jerk" with a discussion).
Regulation of the work of internal organs;
The centers of many unconditioned reflexes are located;
Performs voluntary movements.
Spinal cord injuries (slide number 9)
The spinal cord is very sensitive to injury. Unlike other parts of the body, the spinal cord is unable to repair itself if damaged. Spinal cord injuries can occur due to trauma, circulatory disorders, compression, tumors, infections.
Full Damage: there is a complete loss of sensation and muscle function below the level of damage.
Partial damage: body functions are partially preserved below the level of damage.
In most cases, with spinal cord injury, both sides of the body are affected equally. Injuries to the upper cervical spinal cord can cause paralysis in both arms and both legs. If the spinal cord injury occurs in the lower back, it can cause paralysis in both legs.
R
IP
state of emergency
BUT
Collective
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IV .
Anchoring
BUT). Orally (slide number 12):
1. Where is the spinal cord located?
2. What is the gray (white) matter of the brain, where is it located in the spinal cord, what functions does it perform?
3. What are the spinal nerves, their anterior and posterior roots formed by?
4. How are the reflex and conduction functions of the spinal cord carried out?
5. What is the cause of spinal cord injury? What types of spinal cord injuries do you know?
B). At the blackboard:
Sign what is indicated in the picture "Structure of the spinal cord" numbers 1-11 (slides 13-14).
AT). Insert missing words (slide number 15):
The spinal cord looks like a cord with a diameter of about ... and a length of about 42-45 cm. It starts from ... ... and is located inside ... .... On the front and back sides of the spinal cord there are two deep ..., which divide it into the right and left parts. In the center of the spinal cord is a narrow ... ..., running along its entire length. It is filled with... liquid. The spinal cord consists of ... a segment. From each of them a couple departs ... .... They start with two ... - front and rear.
Answer:
1cm, oblong, spinal canal, sulci, spinal canal, spinal cord, 31, spinal nerves, roots.
state of emergency
Frontal
Individual
Individual
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v.
Summarizing
Spinal cord (slide number 16):
cylindrical cord located in the spinal canal;
surrounded by three shells: hard, cobweb and soft;
31 pairs of spinal nerves depart;
the anterior roots of the spinal nerves are formed by the axons of motor neurons, and the posterior roots are formed by the axons of sensory neurons;
provides movement of all parts of the body, limbs, innervating skeletal muscles, causes skin sensitivity;
performs conductive and reflex functions.
The work of the spinal cord is carried out under the control of the brain.
Collective
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VI. D/W:
(slide number 17):
Section 14
Answer the following question in writing:
There is an opinion that taking cerebrospinal fluid from the spine is a very dangerous procedure. Confirm or refute this point of view. For what purpose do neuropathologists analyze this fluid?
PP
Individual
VII.
Reflection
(slide number 18):
Today in class I...
learned...
it was interesting …
it was difficult …
my feelings...
liked the most…
Individual
Literature and Internet sources:
R.Alimkulova., R.Sagimbekov, A.Soloviev. Biology. 8th grade. Almaty "Atamura", 2008, 288s.
E.A. Rezanova, I.P. Antonova, A.A. Rezanov. Human biology in tables and diagrams, "Izdat - School", M., 1998, 204s.
T.L. Bogdanova, E.A. Solodova. Biology, M., "AST - PRESS", 2001, 815.
A.G. Khripkova, D.V. Kolesov. Biology. Man and his health. M., "Enlightenment", 1997, 208s.
G.L. Bilich, V.A. Kryzhanovsky. Biology for entering universities. M., "Onyx", 2008, 1088s.
A.M. Tsuzmer, O.L. Petrishina. Biology. Man and his health, M., "Enlightenment", 1990, 240p.
M.R. Sapin, Z.G. Bryskina. Human anatomy and physiology, M., Enlightenment, 1998, 256p.
A.G. Khripkova. Human physiology. M., "Enlightenment", 1971, 159p.
R.G. Zayats, I.V. Rachkovskaya, V.M. Stambrovskaya Biology, Minsk, Higher School, 2000, 524p.
O.A. Pepelyaeva, I.V. Suntsova. Pourochnye developments in biology (Man). "WAKO", M., 2005, 416s.
G.M.Murtazin. Active forms and methods of teaching biology. M., "Enlightenment", 1989, 193p.
V.A. Lipchenko, R.P. Samusev. Atlas of normal human anatomy. M., "Medicine", 1988, 320s.
Z.A.Vlasova. Biology. Student's handbook. M., 1995, 574s.
I.D.Zverev. Reading book on human anatomy, physiology and hygiene, M., Enlightenment, 1978, 239s
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slide 1
Lesson plan: Functions of the nervous system. Parts of the nervous system. 3. Spinal cord and its location. 4. The structure of the spinal cord. 5. Functions of the spinal cord. 6. Damage to the spinal cord.slide 2
Functions of the nervous system Nervous tissue and neurons Ensures the coordinated work of all organs and systems of the body Carries out the orientation of the body in the external environment and adaptive reactions to its changes. It forms the material basis of mental activity: speech, thinking, social behavior.
slide 3
Nervous system Central Peripheral Spinal cord Brain Nerve endings Nerve nodes Nerves The nervous system is a collection of special structures. Uniting and coordinating the activity of all organs and systems of the body in constant interaction with the external environment
slide 4
The spinal cord (lat. Medulla spinalis) is the tail part of the central nervous system of vertebrates, located in the spinal canal formed by the neural arches of the vertebrae from the I cervical vertebra to the I - II lumbar. Length about 45 cm. Thickness about 1 cm.
slide 5
SECTIONS OF THE SPINAL CORD Nerve ganglion Spinal nerve root Lumbar cauda equina Spinal nerve Sciatic nerve
slide 6
The spinal cord (lat. medulla spinalis) has a relatively simple structural principle and a pronounced segmental organization. It provides connections between the brain and the periphery and carries out segmental reflex activity.
Slide 7
1 - central channel; 2 - posterior root of the spinal nerve; 3 - anterior root of the spinal nerve; 4 - vertebral ganglion; 5 - spinal nerve; 6 - gray matter ("butterfly"); 7 - white matter; 8 - anterior median sulcus.
Slide 8
The pathways of the central nervous system (tractus sistematis nervosi centralis) are groups of nerve fibers that are characterized by a common structure and functions and connect various parts of the brain and spinal cord.
Slide 9
Conductive Reflex 1 - sensitive (afferent) neuron; 2 - intercalary (conductor) neuron; 3 - motor (efferent) neuron; 4 - nerve fibers of the thin and wedge-shaped bundles; 5 - fibers of the cortical-spinal tract.
slide 10
Injury "diver" Myelopathy - compression of the spinal cord (reasons: trauma, inflammation of the Vertebrae, circulatory disorders) Herniated discs
STUDENTS 205 P BABENKO DARIA DMITRIEVNA
Slide 2: The spinal cord (lat. Medulla spinalis) -
organ of the central nervous system of vertebrates located in the spinal canal. Inside the spinal cord there is a cavity called the central canal (lat. Canalis centralis). The spinal cord is protected by the pia, arachnoid and dura mater. The spaces between the membranes and the spinal canal are filled with cerebrospinal fluid. The space between the outer hard shell and the bone of the vertebrae is called the epidural and is filled with adipose tissue and venous network.
slide 3
slide 4
The CM is a band of uneven thickness, compressed from front to back, 45 cm long in men and 41-42 cm in women. Near the upper edge of the atlas, the SM without sharp boundaries passes into the medulla oblongata, and at the level of the 2nd lumbar vertebra it ends with a medullary cone, the thin top of which passes into the terminal thread (filum terminale), which is attached to the 2nd coccygeal vertebra.
slide 5
slide 6
The length of the spinal cord in an adult ranges from 40 to 45 cm, the width is from 1.0 to 1.5 cm, and the mass is on average 35 g. in the anterior and posterior The anterior median fissure and the posterior median sulcus divide the spinal cord into two symmetrical halves.
Slide 7
Slide 8
The spinal cord does not have the same diameter throughout. Its thickness increases slightly from bottom to top. The largest size in diameter is noted in two spindle-shaped thickenings: in the upper section - this is the cervical thickening (lat. intumescentia cervicalis), corresponding to the exit of the spinal nerves going to the upper limbs, and in the lower section - this is the lumbosacral thickening (lat. intumescentia lumbosacralis) , - the place of exit of nerves to the lower extremities. The cervical thickening begins at the level of the III-IV cervical vertebra, reaches the II thoracic vertebra, reaching the greatest width at the level of the V-VI cervical vertebra. The lumbosacral thickening extends from the level of the IX-X thoracic vertebra to the 1st lumbar, its greatest width corresponds to the level of the XII thoracic vertebra (at the height of the 3rd lumbar spinal nerve).
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slide 12
The CM segment is the segment of the CM corresponding to each pair (right and left) of the spinal nerves. In SM, a trace is distinguished. segments: 1. Neck segments - 8 (С 1 -С 8); 2. Thoracic segments -12 (Th 1 -Th 12); 3. Lumbar -5 (L 1 -L 5); 4. sacral - 5 (S 1 -S 5); 6. Coccygeal –1 (C o 1) during embryonic development, the spinal column grows faster.
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slide 13
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Slide 14
There is Shipo's rule about the ratio of segments of the spinal cord and the spinal column. In the cervical and upper thoracic regions, the segments of the spinal cord are located one vertebra above their corresponding vertebra. In the middle chest - two vertebrae higher, in the lower chest - three vertebrae higher. Therefore, the spinal cord ends at the level of the 2nd lumbar vertebra. Below this level, the spinal cord forms a cauda equina (cauda equina), which consists of the roots of the spinal nerves L 1 - C o 1, descending down to the corresponding intervertebral foramina.
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slide 15
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Slide 16: NEURONS OF THE SPINAL CORD. HISTOLOGY
The human spinal cord contains about 13 million neurons, of which 3% are motor neurons, and 97% are intercalary. Functionally, neurons of the spinal cord can be divided into 4 main groups: 1) motoneurons, or motor, - cells of the anterior horns, the axons of which form the anterior roots; 2) interneurons - neurons that receive information from the spinal ganglia and are located in the posterior horns. These neurons respond to pain, temperature, tactile, vibrational, proprioceptive stimuli; 3) sympathetic, parasympathetic neurons are located mainly in the lateral horns. The axons of these neurons exit the spinal cord as part of the anterior roots; 4) associative cells - neurons of the spinal cord's own apparatus, establishing connections within and between segments.
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Slide 19
On the cross section of the spinal cord, white and gray matter are distinguished. The gray matter is in the center, looks like a butterfly or the letter “H”, is formed by neurons (their diameter does not exceed 0.1 mm), thin myelinated and non-myelinated fibers. The gray matter is subdivided into anterior, posterior, and lateral horns. In the anterior horns (have a round or quadrangular shape) are the bodies of efferent (motor) neurons - motoneurons, the axons of which innervate skeletal muscles. In the posterior horns (they are narrower and longer than the anterior horns) and partly in the middle part of the gray matter, there are bodies of intercalary neurons, to which afferent nerve fibers approach. In the lateral horns from the 8th cervical to the 2nd lumbar segments of the spinal cord are the bodies of neurons of the sympathetic nervous system, from the 2nd to 4th sacral - the bodies of neurons of the parasympathetic nervous system.
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slide 21
White matter surrounds gray, it is formed by myelinated nerve fibers and is subdivided into anterior, lateral and posterior cords. In the posterior funiculi of the spinal cord, there are ascending pathways, in the anterior cords, descending pathways, and in the lateral cords, ascending and descending pathways. These pathways connect different parts of the spinal cord with each other and with different parts of the brain. The spinal cord has a segmental structure (31 segments), on both sides of each segment there is a pair of anterior and a pair of posterior roots. The posterior roots are formed by axons of afferent (sensitive) neurons, through which excitation from receptors is transmitted to the spinal cord, the anterior roots are formed by axons of motor neurons (efferent nerve fibers), through which excitation is transmitted to skeletal muscles. The functions of the roots were studied by Bell and Magendie: with unilateral transection of the posterior roots, the animal loses sensation on the side of the operation, but the motor function is preserved; when transection of the anterior roots, paralysis of the limbs is observed, but sensitivity is completely preserved.
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Associative fibers also pass through the white matter of the spinal cord. They carry out connections between segments of the spinal cord and form anterior, lateral and posterior bundles of their own (Latin fasciculi proprii ventrales, laterales et dorsales), which are adjacent to the gray matter of the spinal cord, surrounding it from all sides. These bundles include: dorsolateral path (lat. tractus dorsolateralis) - a small bundle of fibers located between the top of the posterior gray column and the surface of the spinal cord in close proximity to the posterior root; septal-marginal bundle (lat. fasciculus septomarginalis) - a thin bundle of descending fibers, closely adjacent to the posterior median fissure, can be traced only in the lower thoracic and lumbar segments of the spinal cord, the interfascicular bundle (lat. fasciculus interfascicularis) - is formed by descending fibers located in the medial part of the sphenoid bundle, can be traced in the cervical and upper thoracic segments.
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slide 24
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Slide 25: FUNCTIONS OF THE SPINAL CORD
The spinal cord is connected by afferent and efferent nerve fibers to the trunk and limbs. The axons of afferent neurons enter the spinal cord, bringing impulses from the skin, the motor apparatus (skeletal muscles, tendons, joints), as well as from the internal organs and the entire vascular system. Axons of efferent neurons emerge from the spinal cord, carrying impulses to the muscles of the trunk and limbs, skin, internal organs, and blood vessels. In lower animals there is great independence in the work of the spinal cord. It is known that a frog, while maintaining the medulla oblongata and spinal cord, can swim and jump, and a decapitated chicken can take off. In the human body, the spinal cord loses its autonomy, its activity is controlled by the cerebral cortex.
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slide 26
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Slide 27
The spinal cord performs the following functions: afferent, reflex, conduction.
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Slide 28
The afferent function consists in the perception of stimuli and the conduction of excitation along the afferent nerve fibers (sensory or centripetal) to the spinal cord. The reflex function lies in the fact that in the spinal cord there are reflex centers of the muscles of the trunk, limbs and neck, which carry out a number of motor reflexes, for example, tendon reflexes, body position reflexes, etc. Many centers of the autonomic nervous system are also located here: vasomotor, sweating, urinary , defecation, activity of the genital organs. All reflexes of the spinal cord are controlled by impulses coming to it along descending pathways from various parts of the brain. Therefore, partial or complete injuries of the spinal cord cause sharp disturbances in the activity of the spinal centers.
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Slide 29
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slide 30
The conductor function consists in the transmission of excitation along numerous ascending pathways to the centers of the brain stem and to the cerebral cortex. From the overlying parts of the central nervous system, the spinal cord receives impulses along descending pathways and transmits them to the skeletal muscles and internal organs.
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Slide 31
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Slide 32: ASCENDING WAYS
formed by axons of receptor or intercalary neurons. These include: Gaulle's bundle and Burdakh's bundle. They transmit excitation from proprioceptors to the medulla oblongata, then to the thalamus and cerebral cortex. Anterior and posterior spinal tracts (Govers and Flexig). Nerve impulses are transmitted from proprioreceptors through interneurons to the cerebellum. The lateral spinothalamic pathway transmits impulses from interoreceptors to the thalamus - this is the pathway for information from pain and temperature receptors. - The ventral spinothalamic pathway transmits impulses from interoreceptors and tactile skin receptors to the thalamus.
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Slide 33
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Slide 34: DOWNWARDS
formed by axons of neurons of the nuclei, which are located in different parts of the brain. These include: Corticospinal or pyramidal pathways carry information from pyramidal cells of the cerebral cortex (from motor neurons and autonomic zones) to skeletal muscles (voluntary movements). The reticulo-spinal path - from the reticular formation to the motor neurons of the anterior horns of the spinal cord, maintains their tone. The rubrospinal pathway transmits impulses from the cerebellum, quadrigemina and red nucleus to motor neurons, maintains skeletal muscle tone. The vestibulospinal pathway - from the vestibular nuclei of the medulla oblongata to the motor neurons, maintains the posture and balance of the body.
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Slide 36: SPINAL CORD REFLEXES
The principle of operation of the segmental apparatus of the spinal cord is reflex arcs. The basic scheme of the reflex arc of the spinal cord: information from the receptor goes through the sensitive neuron, it switches to the intercalary neuron, which, in turn, to the motor neuron, which carries information to the effector organ. The reflex arc is characterized by sensory input, involuntariness, intersegmentation, and motor output. Examples of spinal reflexes are: Flexion (flexor) reflex - a protective type reflex aimed at removing a damaging stimulus (withdrawing a hand from a hot one). Stretch reflex (proprioceptive) - preventing excessive stretching of the muscle. A feature of this reflex is that the reflex arc contains a minimum of elements - muscle spindles generate impulses that pass to the spinal cord and cause monosynaptic excitation in α-motor neurons of the same muscle. Tendon, various tonic and rhythmic reflexes. In quadrupeds, an extensor impulse can be observed.
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slide 38: pathology
Spinal cord injury is called myelopathy and can lead, depending on the level of spinal cord injury, to paraplegia or quadriplegia. In the case of a chronic inflammatory reaction, ankylosing spondylitis may develop. Radicular syndrome - neuralgia of the spinal cord.
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Slide 39
"Features of the structure of the brain" - Parts of the diencephalon. Sections of the brain. General information. Lobes of the cerebral cortex. The structure of the big brain. Location of gray and white matter. Dictionary. The location of the brain. Label the parts of the brain. The hypothalamo is the pituitary system. cranial nerves. Functions of the medulla oblongata. The structure of the brain. Brain stem. epiphysis Repeat and remember. Cerebellum. Thalamus.
"Subcortical nuclei of the brain" - Functions of the hypothalamus. Modern ideas about the functions of the hypothalamus. connections of the hypothalamus. Ventroposterior medial nucleus of the VPM. mediators. striopallidary system. Basal ganglia. motor core. Information analysis. afferent influences. Integrative Center. motor nuclei. projection nuclei. Sense centers in the hypothalamus. The thalamus is the highest pain center. The cerebral cortex. Inhibition in the nuclei of the thalamus.
"Departments of the spinal cord" - 31 pairs of spinal nerves. The value of cerebrospinal fluid. Knowledge of the structure and functions of the nervous system. Spinal cord injury. The spinal cord is surrounded by three membranes. Brain. Border of gray and white matter. Spinal cord. Functions of the spinal cord. Consolidation of the studied material. Cylindrical The structure of the spinal cord.
"The structure of the brain" - Absolute mass. Turgenev. Brain. The location of the brain. Brain in numbers. Midbrain. Cerebellum. Brain stem. The human brain. Pons. Functions of the brain. The structure of the brain. Medulla. Sections of the brain. Head. General characteristics. Hemispheres of the brain.
"Human spinal cord" - The spinal cord. The spinal cord of a frog. The spinal cord consists of 31 segments. Intercalary neurons. Functions of the spinal cord. Paralysis of a certain muscle group. Movement becomes impossible. Repetition. Simple motor reflexes. Conduction of impulses. The structure of the spinal cord. Easy experiments. Spinal nerve injury. Nerves. The spinal cord is made up of white matter. Mixed character.
"The brain and its structure" - Axons. Back brain. Neuron. Forebrain. sensory stimuli. Human brain. The human nervous system. Midbrain. The brain and its structure. Cortex. thalamus and hypothalamus. The structure of the brain. bodies of neurons. Brain.
PRESENTATION ON PHYSIOLOGY ON THE TOPIC: "SPINAL CORD". Completed by: Student 205 A group Avakyan A. A. Supervisor: Anointed I. A.
Structure of the spinal cord The spinal cord is located inside the spinal column. It starts from the brain and looks like a white cord with a diameter of about 1 cm. On the front and back sides, the spinal cord has deep anterior and posterior longitudinal grooves. They divide it into right and left parts. On a transverse section, one can see a narrow central canal running along the entire length of the spinal cord. It is filled with cerebrospinal fluid.
The structure of the spinal cord The spinal cord consists of white matter located at the edges, and gray matter located in the center and looking like butterfly wings. In the gray matter are the bodies of nerve cells, and in the white - their processes. Motor neurons are located in the anterior horns of the gray matter of the spinal cord (in the anterior wings of the "butterfly"), and intercalary neurons are located in the posterior horns and around the central canal.
Structure of the spinal cord The spinal cord consists of 31 segments. A pair of spinal nerves depart from each segment, starting with two roots - anterior and posterior. Motor fibers pass in the anterior roots, and sensory fibers enter the spinal cord through the posterior roots and terminate on the intercalary and motor neurons. In the posterior roots there are spinal ganglia, in which clusters of bodies of sensitive neurons are located.
Structure of the spinal cord 1. Anterior root 2. Spinal nerve 3. Spinal ganglion 4. Posterior root 5. Posterior sulcus 6. Spinal canal 7. White matter 8. Posterior horns 9. Lateral horns 10. Anterior horns 11. Anterior sulcus
Functions of the spinal cord The spinal cord performs two main functions: reflex and conduction. The reflex function lies in the fact that the spinal cord provides for the implementation of skeletal muscle contraction, both simple reflexes, such as extension and flexion of the limbs, hand withdrawal, knee reflex, and more complex reflexes, which, in addition, are controlled by the brain.
FUNCTIONS OF THE SPINAL CORD Reflex Gray matter Conductive White matter Carrying out motor impulses sensitive to the muscles of the body by impulses from the skin, descending conductive tendons, joints, paths of pain and temperature receptors Performs voluntary movements Along ascending paths, connection of the brain and spinal cord
Functions of the spinal cord Nerves depart from the segments of the cervical and upper thoracic parts of the spinal cord to the muscles of the head, upper limbs, organs of the chest cavity, to the heart and lungs. The remaining segments of the thoracic and lumbar parts control the muscles of the trunk and abdominal organs, and the lower lumbar and sacral segments of the spinal cord control the muscles of the lower extremities and lower abdominal cavity.
Nerve impulses from the receptors of the skin, muscles and internal organs are carried along the white matter of the spinal cord to the brain, and impulses from the brain are sent to the executive neurons of the spinal cord. This is the conductive function of the spinal cord.
Spinal Cord Injuries Complete Injury: There is complete loss of sensation and muscle function below the level of injury. Partial Damage: Partially retained body functions below the level of damage. In most cases, with spinal cord injury, both sides of the body are affected equally. Injuries to the upper cervical spinal cord can cause paralysis in both arms and both legs. If the spinal cord injury occurs in the lower back, it can cause paralysis in both legs.
Conducting pathways of the spinal cord Ascending pathways Thin bundle (Gaulle) Sphenoid bundle (Burdakh), passes in the posterior columns, impulses enter the cortex Conscious impulses from the musculoskeletal system spinal cerebellar Dorsal horns Impulses from proprioreceptors of muscles, tendons, ligaments; impulses unconscious spinothalamic Lateral and anterior pain and temperature sensitivity, tactile (touch, pressure)
Descending pathways corticospinal (pyramidal) Lateral and anterior Impulses from the cortex to the skeletal muscles, voluntary movements Red-nuclear spinal cord (Monakova) lateral columns Impulses that maintain the tone of the skeletal muscles Vestibulospinal anterior columns Impulses that maintain the posture and balance of the body Tectospinal anterior columns Impulses that ensure the implementation of visual and auditory motor reflexes (reflexes of the quadrigemina)
conduction of sensitivity (paths of Gaulle and Burdach) spinal cerebellar tracts (path of Flexig and Gowers) pyramidal tracts Extrapyramidal tracts.
The doctrine of reflexes Jiří Prochazka (1749-1820) was the first to extend the concept of a reflex to the entire activity of the nervous system, and not just its lower divisions. He believed that a living organism selectively reacts to external influences, evaluating them in relation to the needs of the organism: “External impressions arising in sensory nerves spread very quickly along their entire length to the very beginning. There they are reflected according to a certain law, pass to certain motor nerves corresponding to them, and are extremely quickly sent along them to the muscles, through which they produce precise and strictly limited movements.
Classification of reflexes 1) according to biological significance: a) vital (food, defensive, homeostatic, energy saving, etc.) b) zoosocial (sexual, children's and parental, territorial, schooling) c) self-development (research, play, freedom, imitative); 2) depending on the type of irritated receptors: exteroceptive, interoceptive, proprioceptive; 3) by the nature of the response: 1 - motor or motor (to the muscles), 2 - secretory (to the glands), 3 - vasomotor (to the vessels).
Reflex - the reaction of the body to changes in the external or internal environment, carried out with the participation of the central nervous system (R. Descartes). Monosynaptic Polysynaptic afferent Intercalary efferent neuron According to modern concepts, reflexes are "looped" because the result of the action affects the receptor that triggers this reflex (functional systems).
Examples of reflex arcs Monosynaptic, as a result of a sharp stretching of the proprioreceptors of the quadriceps muscle, the lower leg is extended. But: even the simplest reflexes do not work separately. (Here: interaction with the inhibitory chain of the antagonist muscle)
Examples of reflex arcs Defensive reflex Polysynaptic Irritation of skin receptors leads to coordinated activation of interneurons of one or different segments of the spinal cord
Examples of reflex arcs Reciprocal inhibition of the muscles of antagonists § is the mutual (conjugated) inhibition of the centers of antagonistic reflexes, which ensures the coordination of these reflexes. The phenomenon is functional, i.e. muscles are not always antagonistic
Examples of reflex arcs 4 - disinhibition 4 1 3 2 A. continuous excitation of the motor centers of the central nervous system is divided into successive acts of excitation of the right and left legs. (reciprocal + reciprocal inhibition) B. control of movement with the help of a postural reflex (reciprocal inhibition)
Examples of reflex arcs Muscle receptors: 1. muscle spindles (intrafusal fibers) Gamma loop (control of movement) 2. Golgi tendon complexes
Conditioned reflexes - a combination of an indifferent (unconditioned) reflex with a conditioned stimulus (IP Pavlov) Essence: An indifferent stimulus (U) causes an orienting reflex (activation of a large number of nerve centers). If at the same time (or a little later) the salivation reflex is activated (unconditioned - B), a temporary connection (association) will form.