The tree of Life

The tree of Life

Lesson topic:

Spinal cord structure.

Basic terms and concepts:

Neurons are nerve cells that have different shapes.

Processes of neurons - axons (long) and dendrites (short).

Synapses (contacts) are the junctions of nerve cells.

Nerves are bundles of long processes of nerve cells.

Nerve nodes are accumulations of neuronal bodies outside the central nervous system.

LET'S REPEAT: neuron structure

dendrites

LET'S GET TO KNOW: types of neurons:

Sensitive

Executive

Carry out

information from

body surface

and internal

organs in the brain

Carry signals

from the brain

to the organs.

Interlocking

(mixed)

Analyze

information and

develop

solutions

LET'S BE SURPRISED:

synapse - the place of contact of neurons with each other and with other cells

Checking ourselves:

The structure of the nervous system

Nervous system

Peripheral

nervous system

Central

nervous

system (CNS)

nerves

Nervous

knots

Nervous

endings

Dorsal

brain

Head

brain

Spinal cord (back view)

The spinal cord lies in the spinal canal. It is a strand with a diameter of about 1 cm. At the top it passes into the brain, at the bottom it ends in the lumbar region. The spinal cord is located in the cerebrospinal fluid. 31 pairs of spinal nerves depart from it.

Reflex arc - the path along which nerve impulses are conducted during the exercise of the reflex

Spinal cord functions:

• Reflex - here are the centers of unconditioned reflexes.
• Conductive - the white matter of the spinal cord provides communication between all parts of the central nervous system.

BRAIN

REGULATES THE SPINAL WORK !!!

Group 5. Knee reflex

1- receptors

2 - sensitive neuron of the spinal cord

3 - motor neuron

4 - axon of the motor neuron

5 - nerve endings in the muscles

Group 4. Cross section of the spinal cord

1 - white matter

2 - gray matter

3 - spinal canal

4 - nerve node

6 - roots of the spinal nerves

Group 1 . Right answers: 2, 3.

Group 2: Insert the missing words.

The spinal cord is a long, cylindrical cord located in the vertebral canal. Above, the spinal cord passes into the brain, below it ends at the level of the second lumbar vertebra. The spinal cord is located in the cerebrospinal fluid. The central canal runs in the center of the spinal cord.

Group 3. Spine injury. Why is it dangerous? Why does the Olympic champion not feel her legs after a spinal injury? How to transport a victim with a spinal injury?

Take a position:

"Yes or no"

1. DIVING DOWN HEAD IN WATER IN UNKNOWN LOCATIONS IS VERY DANGEROUS. 2. IN THE HUMAN BODY THERE IS NOT ANY PART OF THE BODY WHERE THERE WERE ARE NO ENDINGS OF NERVES. 3. HOW MUCH INITIES AND WITS THANKS OUR TRAINERS DUROVS! THE BEAR IS A ROPE RIDER, PASSENGER MOUSE AND MANY OTHER "ARTISTS" SHOW THEIR NUMBERS, WHICH ARE DEVELOPED BY THEM BASED ON UNCONDITIONAL REFLEXES. 4. THE SPINAL CORD IS CONNECTED WITH THE HEAD THROUGH THE CEREBELLA.

• Study paragraph 44.

The spinal cord is a cylindrical, elongated cord, somewhat flattened from front to back, located in the spinal canal. The length of the spinal cord in men is about 45 cm, in women, see The mass of the spinal cord is about 30 g, which is 2.3% of the mass of the brain. The upper edge is at the level of the I-th cervical vertebra, the lower one at the level of the I-II-lumbar vertebra. External structure of the spinal cord

The spinal cord is divided into 5 sections: Cervical Thoracic Sacral Coccygeal Each section is divided into segments according to the number of outgoing pairs of spinal nerve roots. The cervical spine has 8 segments (C1-C8), thoracic-12 (Th1-Th12), lumbar-5 (L1-L5), coccygeal-1,2 segments (Co1-Co2). The spinal cord has 2 thickenings throughout its entire length: Cervical - corresponding to the outlet of the spinal nerves going to the upper extremities. Lumbar - corresponding to the output of the nerves that innervate the lower extremities.

Gray matter The gray matter of the spinal cord is formed by the bodies of neurons, myelin-free and thin myelin fibers, and neuroglia. The anterior horns (pillars) contain the bodies of the largest spinal cord neurons (microns in diameter). They form five cores (clusters). These nuclei are the motor (motor) centers of the spinal cord. The axons of these cells make up the bulk of the fibers of the anterior roots of the spinal nerves. The gray matter of the hind horns (pillars) is heterogeneous. In addition to neuroglia, the dorsal horns contain a large number of intercalary neurons, with which part of the axons coming from sensory neurons in the dorsal roots contact.

White matter White matter of the spinal cord and brain - consists mainly of clusters of nerve fibers, processes of nerve cells that have a myelin sheath (hence the white color of fibers and matter). The white matter has a pronounced segmentation. So, the back, front and side grooves are separators that form the so-called cords: Anterior cord. Anatomically, the anterior columns are localized between the anterior horn of the gray matter and the anterior median fissure. Posterior cord. Anatomically, the posterior cords are localized between the posterior and anterior horns of the gray matter of the spinal cord. Lateral cord. Anatomically, it is located between the posterior and anterior horns. In this cord, both ascending and descending paths are located.

Spinal cord meninges The spinal cord is covered by 3 meninges throughout its entire length. The first (inner) lining of the spinal cord is called soft. It carries the arterial and venous vessels that supply the spinal cord with blood. The second (middle) is arachnoid (arachnoid). Between the inner and middle membranes is the subarachnoid (subarachnoid) space containing cerebrospinal fluid (CSF). When performing a lumbar puncture, the needle must fall into this space so that the CSF can be taken for analysis. The third (outer) shell of the spinal cord is hard. The dura mater continues to the intervertebral foramen, accompanying the nerve roots.

Functions of the spinal cord The spinal cord performs two important functions - reflex and conduction. Each of its segments is associated with specific organs, ensuring their functionality. The conductive functions of the spinal cord are to conduct an impulse along the ascending path to the brain, and from there - along the descending path in the form of a return command to some organ. Reflex functions are simple, natural reflexes.

Reflex function The nervous system functions according to reflex principles. A reflex is the body's response to external or internal influences and spreads along a reflex arc. A reflex arc is a chain of nerve cells; a path traversed by nerve impulses when a reflex is exercised. It consists of: A receptor-nerve link that perceives irritation. Afferent link - carries out the transmission of impulses. The central link is the nerve center. Efferent link - carries out transmission from the nerve center to the effector. Effector is an executive organ. Its activity changes as a result of a reflex. Executive body - activates the work of the body. There are 2 types of reflex arc: Monosynaptic two-neuronal reflex arc. Polysynaptic reflex arc (3 or more neurons)

Conductive function The conductive function of the spinal cord is to transmit impulses from the periphery (from the skin, mucous membranes, internal organs) to the center (brain) and vice versa. The conductors of the spinal cord, which make up its white matter, carry out the transmission of information in the ascending and descending directions. An impulse about external influence is sent to the brain, and a certain sensation is formed in a person. The brain receives impulses not only about touch, but also about the position of the body in space, the state of muscle tension, pain, and so on. Downward impulses allow the brain to "direct" the body. Thus, what a person has conceived is carried out with the help of the spinal cord.

Pathologies and traumatic lesions of the spinal cord: Spinal compression: Spinal stroke occurs as a result of vascular blockage, aortic aneurysm, myocardial infarction, tumor processes or vertebral osteochondrosis. Pain symptoms are complemented by impaired sensitivity, pelvic disorders, flaccid paralysis; Myelitis is a spinal inflammation that includes gray and white matter, which occurs with vaccine allergies, spinal injuries, or general infections. Pain and high fever are complemented by paralysis of the limbs; An epidural abscess is characterized by fever, pain, and paralysis; Compression myelopathy is a group of pathologies associated with external factors (osteochondrosis, intervertebral hernias, the effects of radiation, alcoholic or other intoxication). It is manifested by degenerative changes, spinal ischemia, mechanical compression; Myelomatosis is a proliferative growth of myeloma cells, and not only in the spine, but also in other parts of the skeleton. Pain and weakness are complemented by indicators of leukemia in the analyzes; Syringomyelia - destruction of the brain substance with the formation of a fistula, which causes the loss of motor and tactile function in the limbs; Spinal tumors are divided into metastatic (more common) and primary (can be located directly in the medulla or press on it from the outside); A displaced or fractured spinal injury causes pain and paralysis in the area below the injury;

Inflammatory myelopathies Acute myelitis, which occurs primarily on the basis of infection or secondarily as a complication of focal infection in other organs, is accompanied by fever and progressive paralysis; Infectious myelopathy is a consequence of a viral infection, poliomyelitis, or HIV.

Conclusion The spinal cord is a very important anatomical structure. Its normal functioning ensures all human activity. It serves as an intermediate link between the brain and various parts of the body, transmitting information in the form of impulses in both directions. Knowledge of the structure and functioning of the spinal cord is necessary for the diagnosis of diseases of the nervous system.

Slide 1

Slide 2

Slide 3

Slide 4

Slide 5

Slide 6

Slide 7

Slide 8

Slide 9

Slide 10

1 slide

Lesson number 11. Spinal cord: structure, functions Orlova VN, teacher of chemistry and biology, MAOU "Gymnasium Tarasovka", pos. Cherkizovo, Pushkinsky district, Moscow region

2 slide

To study the structure of the spinal cord and the functions that it performs in our body. Stimulate the development of cognitive interest Predict the consequences for a person of dysfunction of the spinal cord Lesson objectives:

3 slide

The spinal cord is located in the spinal canal and in adults is a long (45 cm in men and 41-42 cm in women) cylindrical cord, weighing 30-40 g and a diameter of about 1 cm.The spinal cord begins at the level of the foramen magnum and ends in a conical sharpening, at the level of the 2nd lumbar vertebra. The spinal cord is much shorter than the spine and because of this, the nerve roots extending from the spinal cord form a dense bundle, which is called the “cauda equina”.

4 slide

Structure: Five sections: cervical, thoracic, lumbar, sacral, coccygeal Length 45 cm in men (41-42 in women) Weight 30 g Diameter 1 cm Surrounded by three membranes: Hard Arachnoid Soft Spinal cord Has two thickenings: cervical, associated with innervation arms, and lumbar, associated with the innervation of the legs. The nervous system is formed by the brain and spinal cord, as well as all their branches - nerves and nerve nodes. The nervous system is a huge community of over ten billion well-functioning cells - neurons. The oldest and most durable part of the human nervous system is the spinal cord. Today in the lesson you will get acquainted with the features of the external and internal structure and functions of the spinal cord. The spinal cord is 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 a diameter of about 1 cm. (Slide No. 3) The spinal cord begins at the level of the greater occipital openings of the skull and ends with a conical sharpening, at the level of the 2nd lumbar vertebra. The spinal cord is much shorter than the spine, and because of this, the nerve roots extending from the spinal cord form a dense bundle, which is called the “cauda equina”.

5 slide

Spinal canal - filled with cerebrospinal fluid Gray matter White matter Cross section of the spinal cord: The anterior and posterior longitudinal grooves divide it into two symmetrical halves. The cross section clearly shows that in the center of the spinal cord around the spinal canal are the bodies of neurons that form the gray matter of the spinal cord. Around the gray matter are the processes of the nerve cells of the spinal cord itself, as well as the axons of the neurons of the brain and peripheral nerve nodes entering the spinal cord, which form the white matter of the spinal cord. In cross section, the gray matter looks like a butterfly; it distinguishes front, back and side horns

6 slide

The importance of cerebrospinal fluid Conducting nutrients to the cells of the spinal cord Shock absorber Takes part in the removal of metabolic products Possesses bactericidal properties Cerebrospinal fluid: Amount: 120 - 150 ml per day Can be renewed up to six times a day

7 slide

8 slide

9 slide

10 slide

Motor neurons (motor neurons) Cross section of the spinal cord: The anterior horns contain the bodies of motor neurons (motor neurons), along the axons of which excitation reaches the skeletal muscles of the limbs and trunk, causing them to contract.

11 slide

12 slide

Neurons of the sympathetic division of the autonomic nervous system Cross section of the spinal cord:

13 slide

The spinal cord is divided into segments, from each of which a pair of mixed (i.e., containing motor and sensory fibers) spinal nerves depart. There are 31 such pairs in total. Each segment of the spinal cord innervates a certain part of the human body. The nerves of the cervical and upper thoracic segments innervate the muscles of the neck, upper limbs and organs located in the thoracic cavity. The nerves of the lower thoracic and upper lumbar segments innervate the muscles of the trunk and abdominal organs. The nerves of the lower lumbar and sacral segments control the muscles of the lower extremities and organs located in the pelvic region

14 slide

Functions of the spinal cord Reflexive Gray matter Conductive White matter Carrying out motor impulses to the muscles of the body along the descending pathways Carrying out sensory impulses from the skin, tendons, joints, pain and temperature receptors Carrying out voluntary movements Along the ascending pathways, communication of the brain and spinal cord

15 slide

Spinal Cord Injury Complete injury: There is a complete loss of sensation and muscle function below the level of injury. Partial damage: partial body functions are preserved below the level of damage In most cases, when the spinal cord is injured, both sides of the body are equally affected. Injuries to the upper cervical spinal cord can cause paralysis of both arms and both legs. If spinal cord injury occurs in the lower back, it can cause paralysis in both legs.

Lesson plan Date Class ____ 8th

Lesson 14 biology

Teacher

Lesson topic: FROM pinnacle brain. Gray and white matter of the spinal cord, central canal. Nerves extending from 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 structural features and functions of the spinal cord.

Lesson objectives.

Educational: to 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 function of the spinal cord;

Developing: continue to develop the ability to think logically, draw conclusions, compare, generalize;

Educational: continue to shape the scientific outlook of students.

Equipment: table "Spinal cord", "Electronic manualin biology. Grade 8 "Volkova T.V. (ISBN978-601-7438-01-2), presentation, flash videos "Substances of the brain", "Reflex arc of the knee reflex".

During the classes

Lesson stage

MO

FOPD

Preparation for VOUD, UNT

Assignments for the development of functional literacy

Individual correctional work

I ... Org. moment

Organizational and psychological attitude.

Greeting. Preparing the class for work. The presence of students.

Collection

II ... Check

d / s:

AND). Orally:

1. The role of the nervous system in the human body.

2. What cells form nerve tissue? What are its properties and values?

3. Why a neuron is considered a structural and functional unit of the nervous system.

4. What is the structure of the neuron?

5. List 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). The "Hot stool" strategy over concepts on the topic "Structure and function of the nervous system. Reflex and reflex arc "(neuron, axon, dendrites, myelin sheath, nerves, nerve nodes, neuroglia, synapse, mediator, 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:

1st group

The leaf reaches for the light, the worm crawls into the darkness, the frog looks for wet places, the dog answers the call, the person pulls his hand away from the hot object. Why?

Group 2:

The man walked barefoot, stepped on a sharp object and his leg was instantly retracted; suddenly the phone rang and you reach out to the telephone receiver; when the light is turned on in a dark room, a person closes his eyes;in a dog eating food, the sight of a cat causes salivation to stop; the newborn firmly grabs any object that falls into his hands.Which of the proposed examples relate to unconditioned reflexes, and which to conditioned? Explain the answer.

Group 3:

A mosquito sat on the face of the sleeping man. He drove 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?

4 group:

Newborns (especially premature babies) show the Robinson reflex. The child firmly grabs any object that falls into his hands. Explain the meaning of this reflex. What happens to this reflex in the child in the future and why?

PP

State of emergency

Frontal

Individual

Working in groups

+

+

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 billions of well-functioning cells - neurons.

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.

AND). Spinal cord location (slide 3).

The spinal cord is a division of the nervous system that originally arose in noncranial 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- II lumbar vertebrae ends.

B). Meninges (slide 4).

The spinal cord is surrounded by three membranes:solid - the most external;cobweb - average, softly th - the innermost is located inside from the firm and 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). Spinal cord structure (slide 5).

On the front and back sides, the spinal cord has deepanterior and posterior longitudinal furrows. They divide it into right and left parts.

The spinal cord consists ofwhite matter located at the edges, andgray matter , located in the center and having the form of butterfly wings (flash video "Substances of the brain".In gray matter arenerve cell bodies , andin white - their processes .

The cross section of the spinal cord shows thatnarrow center channel filled withcerebrospinal fluid (120 - 150 ml per day) .

The importance of cerebrospinal fluid (slide 6):

carrying nutrients to the cells of the spinal cord;

shock absorber;

takes part in the removal of exchange products;

possesses bactericidal properties;

can be updated up to 6 times a day.

The gray matter of the spinal cord consists offront, lateral and hind horns (slide 7).

In the front horns gray matter aremotor neuron bodies , axons

which formanterior spine.

In the rear horns located intercalary (intermediate, contact) neurons that provide communication between centripetal and centrifugal neurons.The posterior root is formed fibers of sensitive cells , body which are locatedin the spinal nodes.

Through the posterior roots, excitement 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 the motor roots.

Around the gray matter is a white matter formed by long processes of neurons. They formpathways spinal cord.

From the spinal cord departs31 pairs of mixed spinal nerves (8 pairs of cervical, 12 pairs of chest, 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 reflex" with discussion).

Regulation of the work of internal organs;

The centers of many unconditioned reflexes are located;

Performs arbitrary movements.

Spinal cord injuries (slide 9)

The spinal cord is very sensitive to injury. Unlike other parts of the body, the spinal cord is unable to repair itself if it is damaged. Spinal cord injury can occur as a result of trauma, impaired blood supply, compression, tumor, infection.

Total damage: there is a complete loss of sensitivity and muscle function below the level of injury

Partial damage: body functions are partially preserved below the level of damage.

In most cases, when the spinal cord is injured, both sides of the body are equally affected. Injuries to the upper cervical spinal cord can cause paralysis of both arms and both legs. If spinal cord injury occurs in the lower back, it can cause paralysis in both legs.

R
SP
State of emergency

BUT

Collection

+

+

IV .

Anchoring

AND). 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. How are the spinal nerves, their anterior and posterior roots formed?

4. How are the reflex and conductive functions of the spinal cord carried out?

5. What causes spinal cord injury? What types of spinal cord injuries do you know?

B). At the blackboard:

Sign what is indicated in the picture "The structure of the spinal cord" in 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 ... ..., which runs along its entire length. It is filled with ... liquid. The spinal cord consists of ... a segment. From each of them there is a couple ... .... They begin with two ... - front and back.

Answer:

1cm, oblong, spinal canal, grooves, spinal canal, spinal, 31, spinal nerves, roots.

State of emergency

Frontal

Individual

Individual

+

+

V.

Summarizing

Spinal cord (slide number 16):

cylindrical cord located in the spinal canal;

surrounded by three shells: hard, arachnoid and soft;

leaves 31 pairs of spinal nerves;

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, determines the sensitivity of the skin;

performs conductive and reflex functions.

The spinal cord is controlled by the brain.

Collection

+

+

Vi. D / Z:

(slide number 17):

Paragraph 14

Answer the question in writing:

It is believed 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 the lesson I ...

learned ...

it was interesting …

it was difficult …

my feelings ...

i liked the most ...

Individual

Literature and Internet - sources:

R. Alimkulova., R. Sagimbekov, A. Solovieva. Biology. 8th grade. Almaty "Atamura", 2008, 288s.

E.A. Rezanova, I.P. Antonova, A.A. Rezanov. Human biology in tables and diagrams, "Publishing 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., "Education", 1997, 208s.

G.L.Bilich, V.A.Kryzhanovsky. Biology for university applicants. M., "Onyx", 2008, 1088s.

A.M. Tsuzmer, O.L. Petrishina. Biology. Man and his health, M., "Education", 1990, 240s.

M.R.Sapin, Z.G.Bryskina. Human anatomy and physiology, M., "Education", 1998, 256s.

A.G. Khripkova. Human physiology. M., "Education", 1971, 159s.

RG Zayats, IV Rachkovskaya, VM Stambrovskaya Biology, Minsk, "Higher school", 2000, 524s.

O. A. Pepelyaeva, I. V. Suntsova. Lesson development in biology (Man). "VAKO", M., 2005, 416s.

G.M. Murtazin. Active forms and methods of teaching biology. M., "Education", 1989, 193s.

V.A. Lipchenko, R.P. Samusev. Atlas of Normal Human Anatomy. M., "Medicine", 1988, 320s.

Z.A. Vlasova. Biology. Pupil's reference book. M., 1995, 574s.

I.D. Zverev. A book for reading on human anatomy, physiology and hygiene, M., "Education", 1978, 239s

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