The nervous system performs the following test functions. Nervous system.docx - Biology tests on the topic "Nervous system" (8th grade, biology)
The peripheral part of the auditory analyzer is morphologically combined in humans with the peripheral part of the vestibular analyzer, and morphologists call this structure the organum vestibulo-cochleare. It has three sections:
- external ear (external auditory canal, auricle with muscles and ligaments);
- middle ear (tympanic cavity, mastoid appendages, auditory tube)
- inner ear (membranous labyrinth located in the bony labyrinth inside the pyramid of the temporal bone).
1. The outer ear concentrates sound vibrations and directs them to the external auditory opening.
2. The auditory canal conducts sound vibrations to the eardrum
3. The eardrum is a membrane that vibrates when exposed to sound.
4. The malleus with its handle is attached to the center of the eardrum using ligaments, and its head is connected to the incus (5), which, in turn, is attached to the stapes (6).
Tiny muscles help transmit sound by regulating the movement of these ossicles.
7. The Eustachian (or auditory) tube connects the middle ear to the nasopharynx. When the ambient air pressure changes, the pressure on both sides of the eardrum is equalized through the auditory tube.
8. Vestibular system. The vestibular system in our ear is part of the body's balance system. Sensory cells provide information about the position and movement of our head.
9. The cochlea is the organ of hearing directly connected to the auditory nerve. The name of the snail is determined by its spirally convoluted shape. This is a bone canal that forms two and a half turns of a spiral and is filled with fluid. The anatomy of the cochlea is very complex, and some of its functions are still unexplored.
The organ of Corti consists of a number of sensory, hair-bearing cells (12) that cover the basilar membrane (13). Sound waves are picked up by hair cells and converted into electrical impulses. These electrical impulses are then transmitted along the auditory nerve (11) to the brain. The auditory nerve consists of thousands of tiny nerve fibers. Each fiber starts from a specific part of the cochlea and transmits a specific sound frequency. Low-frequency sounds are transmitted through fibers emanating from the apex of the cochlea (14), and high-frequency sounds are transmitted through fibers connected to its base. Thus, the function of the inner ear is to convert mechanical vibrations into electrical ones, since the brain can only perceive electrical signals.
Outer ear is a sound-collecting device. The external auditory canal conducts sound vibrations to the eardrum. The eardrum, which separates the outer ear from the tympanic cavity, or middle ear, is a thin (0.1 mm) partition shaped like an inward funnel. The membrane vibrates under the action of sound vibrations coming to it through the external auditory canal.
Sound vibrations are picked up by the ears (in animals they can turn towards the sound source) and transmitted through the external auditory canal to the eardrum, which separates the outer ear from the middle ear. Catching sound and the entire process of listening with two ears - so-called binaural hearing - is important for determining the direction of sound. Sound vibrations coming from the side reach the nearest ear a few ten-thousandths of a second (0.0006 s) earlier than the other. This insignificant difference in the time of arrival of sound to both ears is enough to determine its direction.
Middle ear is a sound-conducting device. It is an air cavity that connects through the auditory (Eustachian) tube to the cavity of the nasopharynx. Vibrations from the eardrum through the middle ear are transmitted by 3 auditory ossicles connected to each other - the hammer, incus and stapes, and the latter, through the membrane of the oval window, transmits these vibrations to the fluid located in the inner ear - perilymph.
Due to the peculiarities of the geometry of the auditory ossicles, vibrations of the eardrum of reduced amplitude but increased strength are transmitted to the stapes. In addition, the surface of the stapes is 22 times smaller than the eardrum, which increases its pressure on the oval window membrane by the same amount. As a result, even the weak sound waves, acting on the eardrum, are able to overcome the resistance of the membrane of the oval window of the vestibule and lead to fluid vibrations in the cochlea.
During strong sounds, special muscles reduce the mobility of the eardrum and auditory ossicles, adapting the hearing aid to such changes in the stimulus and protecting the inner ear from destruction.
Thanks to the connection of the air cavity of the middle ear with the cavity of the nasopharynx through the auditory tube, it becomes possible to equalize the pressure on both sides of the eardrum, which prevents its rupture during significant changes in pressure in the external environment - when diving under water, climbing to a height, shooting, etc. This is the barofunction of the ear .
There are two muscles in the middle ear: the tensor tympani and the stapedius. The first of them, contracting, increases the tension of the eardrum and thereby limits the amplitude of its vibrations during strong sounds, and the second fixes the stapes and thereby limits its movements. The reflex contraction of these muscles occurs 10 ms after the onset of a strong sound and depends on its amplitude. This automatically protects the inner ear from overload. In case of instantaneous strong irritations (impacts, explosions, etc.), this protective mechanism does not have time to work, which can lead to hearing impairment (for example, among bombers and artillerymen).
Inner ear is a sound-perceiving apparatus. It is located in the pyramid of the temporal bone and contains the cochlea, which in humans forms 2.5 spiral coil. The cochlear canal is divided by two partitions, the main membrane and the vestibular membrane into 3 narrow passages: upper (scala vestibular), middle (membranous canal) and lower (scala tympani). At the top of the cochlea there is an opening that connects the upper and lower canals into a single one, going from the oval window to the top of the cochlea and then to the round window. Its cavity is filled with fluid - peri-lymph, and the cavity of the middle membranous canal is filled with a fluid of a different composition - endolymph. In the middle channel there is a sound-perceiving apparatus - the organ of Corti, in which there are mechanoreceptors of sound vibrations - hair cells.
The main route of delivery of sounds to the ear is airborne. The approaching sound vibrates the eardrum, and then through the chain of auditory ossicles the vibrations are transmitted to the oval window. At the same time, vibrations of the air in the tympanic cavity also occur, which are transmitted to the membrane of the round window. Another way of delivering sounds to the cochlea is tissue or bone conduction . In this case, the sound directly acts on the surface of the skull, causing it to vibrate. Bone pathway for sound transmission becomes of great importance if a vibrating object (for example, the stem of a tuning fork) comes into contact with the skull, as well as in diseases of the middle ear system, when the transmission of sounds through the chain of auditory ossicles is disrupted. In addition to the air path for conducting sound waves, there is a tissue, or bone, path. Under the influence of air sound vibrations, as well as when vibrators (for example, a bone telephone or a bone tuning fork) come into contact with the integument of the head, the bones of the skull begin to vibrate (the bone labyrinth also begins to vibrate) . Based on the latest data (Bekesy and others), it can be assumed that sounds propagating along the bones of the skull only excite the organ of Corti if, similar to air waves, they cause arching of a certain section of the main membrane. The ability of the skull bones to conduct sound explains why to the person himself his voice, recorded on tape, seems foreign when the recording is played back, while others easily recognize it. The fact is that the tape recording does not reproduce your entire voice. Usually, when talking, you hear not only those sounds that your interlocutors also hear (that is, those sounds that are perceived due to air-liquid conduction), but also those low-frequency sounds, the conductor of which is the bones of your skull. However, when listening to a tape recording of your own voice, you hear only what could be recorded - sounds whose conductor is air. Binaural hearing . Humans and animals have spatial hearing, that is, the ability to determine the position of a sound source in space. This property is based on the presence of binaural hearing, or listening with two ears. It is also important for him to have two symmetrical halves at all levels of the auditory system. The acuity of binaural hearing in humans is very high: the position of the sound source is determined with an accuracy of 1 angular degree. The basis for this is the ability of neurons in the auditory system to evaluate interaural (inter-ear) differences in the time of arrival of sound to the right and left ear and the intensity of sound in each ear. If the sound source is located away from the midline of the head, the sound wave arrives at one ear slightly earlier and has greater strength than at the other ear. Assessing the distance of a sound source from the body is associated with a weakening of the sound and a change in its timbre.When the right and left ears are stimulated separately via headphones, a delay between sounds of as little as 11 μs or a 1 dB difference in the intensity of the two sounds results in an apparent shift in the localization of the sound source from the midline towards an earlier or stronger sound. The auditory centers contain neurons that are acutely tuned to a specific range of interaural differences in time and intensity. Cells have also been found that respond only to a certain direction of movement of a sound source in space.
Consists of the outer, middle and inner ear. The middle and inner ear are located inside the temporal bone.
Outer ear consists of the auricle (collects sounds) and the external auditory canal, which ends in the eardrum.
Middle ear- This is a chamber filled with air. It contains the auditory ossicles (hammer, incus and stapes), which transmit vibrations from the eardrum to the membrane of the oval window - they amplify the vibrations 50 times. The middle ear is connected to the nasopharynx via the Eustachian tube, through which the pressure in the middle ear is equalized with atmospheric pressure.
In the inner ear there is a cochlea - a fluid-filled bone canal twisted in 2.5 turns, blocked by a longitudinal septum. On the septum there is an organ of Corti containing hair cells - these are auditory receptors that convert sound vibrations into nerve impulses.
Ear work: When the stapes presses on the membrane of the oval window, the column of fluid in the cochlea moves, and the membrane of the round window protrudes into the middle ear. The movement of the fluid causes the hairs to touch the integumentary plate, causing the hair cells to become excited.
Vestibular apparatus: in the inner ear, in addition to the cochlea, there are semicircular canals and vestibular sacs. Hair cells in the semicircular canals sense fluid movement and respond to acceleration; hair cells in the sacs sense the movement of the otolith pebble attached to them and determine the position of the head in space.
Establish a correspondence between the structures of the ear and the sections in which they are located: 1) outer ear, 2) middle ear, 3) inner ear. Write the numbers 1, 2 and 3 in the correct order.
A) auricle
B) oval window
B) snail
D) stirrup
D) Eustachian tube
E) hammer
Establish a correspondence between the function of the hearing organ and the section that performs this function: 1) middle ear, 2) inner ear
A) conversion of sound vibrations into electrical ones
B) amplification of sound waves due to vibrations of the auditory ossicles
B) equalization of pressure on the eardrum
D) conducting sound vibrations due to the movement of liquid
D) irritation of auditory receptors
1. Establish the sequence of sound wave transmission to the auditory receptors. Write down the corresponding sequence of numbers.
1) vibrations of the auditory ossicles
2) vibrations of fluid in the cochlea
3) vibrations of the eardrum
4) irritation of auditory receptors
2. Establish the correct sequence of passage of a sound wave in the human hearing organ. Write down the corresponding sequence of numbers.
1) eardrum
2) oval window
3) stirrup
4) anvil
5) hammer
6) hair cells
3. Establish the sequence in which sound vibrations are transmitted to the receptors of the hearing organ. Write down the corresponding sequence of numbers.
1) Outer ear
2) Membrane of the oval window
3) Auditory ossicles
4) Eardrum
5) Fluid in the cochlea
6) Hearing receptors
1. Select three correctly labeled captions for the drawing “Structure of the Ear.”
1) external auditory canal
2) eardrum
3) auditory nerve
4) stirrup
5) semicircular canal
6) snail
2. Select three correctly labeled captions for the drawing “Structure of the Ear.” Write down the numbers under which they are indicated.
1) ear canal
2) eardrum
3) auditory ossicles
4) auditory tube
5) semicircular canals
6) auditory nerve
4. Select three correctly labeled captions for the drawing “Structure of the Ear.”
1) auditory ossicles
2) facial nerve
3) eardrum
4) auricle
5) middle ear
6) vestibular apparatus
1. Set the sequence of sound transmission in the hearing analyzer. Write down the corresponding sequence of numbers.
1) vibration of the auditory ossicles
2) vibration of fluid in the cochlea
3) generation of a nerve impulse
5) transmission of nerve impulses along the auditory nerve to the temporal lobe of the cerebral cortex
6) vibration of the oval window membrane
7) vibration of hair cells
2. Establish the sequence of processes occurring in the auditory analyzer. Write down the corresponding sequence of numbers.
1) transmission of vibrations to the membrane of the oval window
2) capturing the sound wave
3) irritation of receptor cells with hairs
4) vibration of the eardrum
5) movement of fluid in the cochlea
6) vibration of the auditory ossicles
7) the occurrence of a nerve impulse and its transmission along the auditory nerve to the brain
3. Establish the sequence of processes of passage of a sound wave in the organ of hearing and a nerve impulse in the auditory analyzer. Write down the corresponding sequence of numbers.
1) movement of fluid in the cochlea
2) transmission of sound waves through the malleus, incus and stapes
3) transmission of nerve impulses along the auditory nerve
4) vibration of the eardrum
5) conduction of sound waves through the external auditory canal
4. Establish the path of the sound wave of a car siren that a person will hear, and the nerve impulse that occurs when it sounds. Write down the corresponding sequence of numbers.
1) snail receptors
2) auditory nerve
3) auditory ossicles
4) eardrum
5) auditory cortex
Choose one, the most correct option. The auditory analyzer receptors are located
1) in the inner ear
2) in the middle ear
3) on the eardrum
4) in the auricle
Choose one, the most correct option. The sound signal is converted into nerve impulses in
1) snail
2) semicircular canals
3) eardrum
4) auditory ossicles
Choose one, the most correct option. In the human body, an infection from the nasopharynx enters the middle ear cavity through
1) oval window
2) larynx
3) auditory tube
4) inner ear
Establish a correspondence between the parts of the human ear and their structure: 1) outer ear, 2) middle ear, 3) inner ear. Write the numbers 1, 2, 3 in the order corresponding to the letters.
A) includes the auricle and external auditory canal
B) includes the cochlea, which contains the initial section of the sound-receiving apparatus
B) includes three auditory ossicles
D) includes the vestibule with three semicircular canals, which contain the balance apparatus
D) a cavity filled with air communicates through the auditory tube with the pharyngeal cavity
E) the inner end is covered by the eardrum
1. Establish a correspondence between structures and analyzers: 1) Visual, 2) Auditory. Write numbers 1 and 2 in the correct order.
A) Snail
B) Anvil
B) Vitreous body
D) Sticks
D) Cones
E) Eustachian tube
2. Establish a correspondence between the characteristics and analyzers of a person: 1) visual, 2) auditory. Write numbers 1 and 2 in the order corresponding to the letters.
A) perceives mechanical vibrations environment
B) includes rods and cones
B) the central section is located in the temporal lobe of the cerebral cortex
D) the central section is located in the occipital lobe of the cerebral cortex
D) includes the organ of Corti
Select three correctly labeled captions for the figure “Structure of the vestibular apparatus.” Write down the numbers under which they are indicated.
1) Eustachian tube
2) snail
3) calcareous crystals
4) hair cells
5) nerve fibers
6) inner ear
Choose one, the most correct option. Pressure on the eardrum equal to atmospheric pressure from the middle ear is provided in humans
1) auditory tube
2) auricle
3) membrane of the oval window
4) auditory ossicles
Choose one, the most correct option. Receptors that determine the position of the human body in space are located in
1) membrane of the oval window
2) eustachian tube
3) semicircular canals
4) middle ear
Choose three correct answers out of six and write down the numbers under which they are indicated. The hearing analyzer includes:
1) auditory ossicles
2) receptor cells
3) auditory tube
4) auditory nerve
5) semicircular canals
6) temporal lobe cortex
Choose three correct answers out of six and write down the numbers under which they are indicated. The middle ear in the human hearing organ includes
1) receptor apparatus
2) anvil
3) auditory tube
4) semicircular canals
5) hammer
6) auricle
Choose three correct answers out of six and write down the numbers under which they are indicated. What should be considered true signs of the human hearing organ?
1) The external auditory canal is connected to the nasopharynx.
2) Sensitive hair cells are located on the membrane of the cochlea of the inner ear.
3) The middle ear cavity is filled with air.
4) The middle ear is located in the labyrinth of the frontal bone.
5) The outer ear detects sound vibrations.
6) The membranous labyrinth amplifies sound vibrations.
© D.V. Pozdnyakov, 2009-2019
For our orientation in the world around us, hearing plays the same role as vision. The ear allows us to communicate with each other using sounds; it has a special sensitivity to the sound frequencies of speech. With the help of the ear, a person picks up various sound vibrations in the air. Vibrations that come from an object (sound source) are transmitted through the air, which plays the role of a sound transmitter, and are captured by the ear. The human ear perceives air vibrations with a frequency of 16 to 20,000 Hz. Vibrations with a higher frequency are considered ultrasonic, but the human ear does not perceive them. The ability to distinguish high tones decreases with age. The ability to pick up sound with both ears makes it possible to determine where it is. In the ear, air vibrations are converted into electrical impulses, which are perceived by the brain as sound.
The ear also houses the organ for sensing movement and position of the body in space - vestibular apparatus. The vestibular system plays a large role in a person’s spatial orientation, analyzes and transmits information about accelerations and decelerations of linear and rotational movement, as well as when the position of the head changes in space.
Ear structure
Based external structure the ear is divided into three parts. The first two parts of the ear, the external (outer) and middle, conduct sound. The third part - the inner ear - contains auditory cells, mechanisms for perceiving all three features of sound: pitch, strength and timbre.
Outer ear- the protruding part of the outer ear is called auricle, its basis is made up of semi-rigid supporting tissue - cartilage. The anterior surface of the auricle has a complex structure and variable shape. It consists of cartilage and fibrous tissue, with the exception of the lower part - the lobule (earlobe) formed by fatty tissue. At the base of the auricle there are anterior, superior and posterior auricular muscles, the movements of which are limited.
In addition to the acoustic (sound-collecting) function, the auricle plays a protective role, protecting the auditory canal into the eardrum from harmful environmental influences (water, dust, strong air currents). Both the shape and size of the ears are individual. The length of the auricle in men is 50–82 mm and width 32–52 mm; in women the sizes are slightly smaller. The small area of the auricle represents all the sensitivity of the body and internal organs. Therefore, it can be used to obtain biologically important information about the condition of any organ. The auricle concentrates sound vibrations and directs them to the external auditory opening.
External auditory canal serves to conduct sound vibrations of air from the auricle to the eardrum. The external auditory canal has a length of 2 to 5 cm. Its outer third is formed by cartilage tissue, and the inner 2/3 is formed by bone. The external auditory canal is arched in the superior-posterior direction, and easily straightens when the auricle is pulled up and back. In the skin of the ear canal there are special glands that secrete a yellowish secretion (earwax), the function of which is to protect the skin from bacterial infection and foreign particles (insects).
The external auditory canal is separated from the middle ear by the eardrum, which is always retracted inward. This is a thin connective tissue plate, covered on the outside with multilayer epithelium, and on the inside with mucous membrane. The external auditory canal serves to conduct sound vibrations to the eardrum, which separates the outer ear from the tympanic cavity (middle ear).
Middle ear, or the tympanic cavity, is a small air-filled chamber that is located in the pyramid of the temporal bone and is separated from the external auditory canal by the eardrum. This cavity has bony and membranous (tympanic membrane) walls.
Eardrum is a low-moving membrane 0.1 microns thick, woven from fibers that run in different directions and are stretched unevenly in different areas. Due to this structure, the eardrum does not have its own period of oscillation, which would lead to amplification of sound signals that coincide with the frequency of its own oscillations. It begins to vibrate under the influence of sound vibrations passing through the external auditory canal. Through an opening on the posterior wall, the tympanic membrane communicates with the mastoid cave.
The opening of the auditory (Eustachian) tube is located in the anterior wall of the tympanic cavity and leads into the nasal part of the pharynx. Thereby atmospheric air may enter the tympanic cavity. Normally, the opening of the Eustachian tube is closed. It opens during swallowing movements or yawning, helping to equalize the air pressure on the eardrum from the side of the middle ear cavity and the external auditory opening, thereby protecting it from ruptures leading to hearing impairment.
In the tympanic cavity lie auditory ossicles. They are very small in size and are connected in a chain that extends from the eardrum to the inner wall of the tympanic cavity.
The outermost bone is hammer- its handle is connected to the eardrum. The head of the malleus is connected to the incus, which movably articulates with the head stirrups.
The auditory ossicles received such names because of their shape. The bones are covered with a mucous membrane. Two muscles regulate the movement of the bones. The connection of the bones is such that it increases the pressure of sound waves on the membrane of the oval window by 22 times, which allows weak sound waves to move the liquid in snail.
Inner ear enclosed in the temporal bone and is a system of cavities and canals located in the bone substance of the petrous part of the temporal bone. Together they form the bony labyrinth, within which is the membranous labyrinth. Bone labyrinth It is a bony cavity of various shapes and consists of the vestibule, three semicircular canals and the cochlea. Membranous labyrinth consists of a complex system of thin membranous formations located in the bony labyrinth.
All cavities of the inner ear are filled with fluid. Inside the membranous labyrinth there is endolymph, and the fluid washing the membranous labyrinth outside is perilymph and is similar in composition to cerebrospinal fluid. Endolymph differs from perilymph (it contains more potassium ions and fewer sodium ions) - it carries a positive charge in relation to perilymph.
Prelude- the central part of the bony labyrinth, which communicates with all its parts. Posterior to the vestibule are three bony semicircular canals: superior, posterior and lateral. The lateral semicircular canal lies horizontally, the other two are at right angles to it. Each channel has an expanded part - an ampoule. It contains a membranous ampulla filled with endolymph. When the endolymph moves during a change in the position of the head in space, the nerve endings are irritated. Excitation is transmitted along nerve fibers to the brain.
Snail is a spiral tube that forms two and a half turns around a cone-shaped bone rod. It is the central part of the hearing organ. Inside the bony canal of the cochlea there is a membranous labyrinth, or cochlear duct, to which the endings of the cochlear part of the eighth cranial nerve approach. Vibrations of the perilymph are transmitted to the endolymph of the cochlear duct and activate the nerve endings of the auditory part of the eighth cranial nerve.
The vestibulocochlear nerve consists of two parts. The vestibular part conducts nerve impulses from the vestibule and semicircular canals to the vestibular nuclei of the pons and medulla oblongata and further to the cerebellum. The cochlear part transmits information along fibers that follow from the spiral (corti) organ to the auditory nuclei of the brainstem and then - through a series of switchings in the subcortical centers - to the cortex of the upper part of the temporal lobe of the cerebral hemisphere.
Mechanism of perception of sound vibrations
Sounds arise due to air vibrations and are amplified in the auricle. The sound wave is then conducted through the external auditory canal to the eardrum, causing it to vibrate. The vibration of the eardrum is transmitted to the chain of auditory ossicles: the malleus, incus and stapes. The base of the stapes is fixed to the window of the vestibule with the help of an elastic ligament, due to which vibrations are transmitted to the perilymph. In turn, through the membranous wall of the cochlear duct, these vibrations pass to the endolymph, the movement of which causes irritation of the receptor cells of the spiral organ. The resulting nerve impulse follows the fibers of the cochlear part of the vestibulocochlear nerve to the brain.
The translation of sounds perceived by the organ of hearing as pleasant and unpleasant sensations is carried out in the brain. Irregular sound waves produce the sensation of noise, while regular, rhythmic waves are perceived as musical tones. Sounds travel at a speed of 343 km/s at an air temperature of 15–16ºС.
A sound wave is a double oscillation of the medium, in which a phase of increasing and decreasing pressure is distinguished. Sound vibrations enter the external auditory canal, reach the eardrum and cause it to vibrate. In the phase of increasing pressure or thickening, the eardrum, together with the handle of the hammer, moves inward. In this case, the body of the anvil, connected to the head of the hammer, due to the suspensory ligaments, moves outward, and the long sprout of the anvil moves inward, thus displacing the stirrup inward. By pressing into the window of the vestibule, the stapes jerkily leads to a displacement of the perilymph of the vestibule. Further propagation of the wave along the staircase of the vestibule transmits oscillatory movements to the Reissner membrane, which in turn sets in motion the endolymph and, through the main membrane, the perilymph of the scala tympani. As a result of this movement of the perilymph, vibrations of the main and Reissner membranes occur. With each movement of the stapes towards the vestibule, the perilymph ultimately leads to a displacement of the membrane of the vestibule towards the tympanic cavity. In the pressure reduction phase, the transmission system returns to its original position.
The air route for delivering sounds to the inner ear is the main one. Another way of conducting sounds to the spiral organ is bone (tissue) conduction. In this case, a mechanism comes into play in which sound vibrations of the air hit the bones of the skull, spread into them and reach the cochlea. However, the mechanism of bone-tissue sound transmission can be twofold. In one case, a sound wave in the form of two phases, propagating along the bone to the liquid media of the inner ear, in the pressure phase will protrude the membrane of the round window and, to a lesser extent, the base of the stapes (taking into account the practical incompressibility of the liquid). Simultaneously with such a compression mechanism, another - inertial option - can be observed. In this case, when sound is conducted through the bone, the vibration of the sound-conducting system will not coincide with the vibration of the skull bones and, therefore, the main and Reissner membranes will vibrate and excite the spiral organ in the usual way. Vibration of the skull bones can be caused by touching it with a sounding tuning fork or telephone. Thus, the bone transmission route becomes of great importance when sound transmission through air is disrupted.
Auricle. The role of the auricle in the physiology of human hearing is small. It has some significance in ototopics and as collectors of sound waves.
External auditory canal. It is shaped like a tube, making it a good conductor of sounds in depth. The width and shape of the ear canal does not play a special role in sound transmission. At the same time, its mechanical blockage prevents the propagation of sound waves to the eardrum and leads to a noticeable deterioration in hearing. In the auditory canal near the eardrum, a constant level of temperature and humidity is maintained, regardless of fluctuations in temperature and humidity in the external environment, which ensures the stability of the elastic media of the tympanic cavity. Due to the special structure of the outer ear, the pressure of the sound wave in the external auditory canal is twice as high as in the free sound field.
Eardrum and auditory ossicles. The main role of the eardrum and auditory ossicles is to transform sound vibrations of large amplitude and low force into vibrations of the fluids of the inner ear with low amplitude and high force (pressure). Vibrations of the eardrum bring the hammer, incus and stirrup into subordination. In turn, the stirrup transmits vibrations to the perilymph, which causes a displacement of the membranes of the cochlear duct. The movement of the main membrane causes irritation of the sensitive hair cells of the spiral organ, as a result of which nerve impulses arise that follow the auditory pathway to the cerebral cortex.
The eardrum vibrates mainly in its lower quadrant with the synchronous movement of the hammer attached to it. Closer to the periphery, its fluctuations decrease. At maximum sound intensity, vibrations of the eardrum can vary from 0.05 to 0.5 mm, with the range of vibrations being larger for low-frequency tones and smaller for high-frequency tones.
The transformation effect is achieved due to the difference in the area of the eardrum and the area of the base of the stapes, the ratio of which is approximately 55:3 (area ratio 18:1), as well as due to the lever system of the auditory ossicles. When converted to dB, the lever action of the auditory ossicular system is 2 dB, and the increase in sound pressure due to the difference in the ratio of the effective areas of the eardrum to the base of the stapes provides a sound amplification of 23 - 24 dB.
According to Bekeshi /I960/, the total acoustic gain of the sound pressure transformer is 25 - 26 dB. This increase in pressure compensates for the natural loss of sound energy that occurs as a result of the reflection of a sound wave during its transition from air to liquid, especially for low and medium frequencies (Wulstein JL, 1972).
In addition to the transformation of sound pressure, the eardrum; also performs the function of sound protection (screening) of the snail window. Normally, sound pressure transmitted through the system of auditory ossicles to the media of the cochlea reaches the window of the vestibule somewhat earlier than it reaches the window of the cochlea through the air. Due to the pressure difference and phase shift, perilymph movement occurs, causing bending of the main membrane and irritation of the receptor apparatus. In this case, the membrane of the cochlear window oscillates synchronously with the base of the stapes, but in the opposite direction. In the absence of the eardrum, this mechanism of sound transmission is disrupted: the next sound wave from the external auditory canal simultaneously in phase reaches the window of the vestibule and the cochlea, as a result of which the effect of the wave cancels out each other. Theoretically, there should be no shift of the perilymph and irritation of the sensitive hair cells. In fact, with a complete defect of the eardrum, when both windows are equally accessible to sound waves, hearing is reduced to 45 - 50. Destruction of the chain of auditory ossicles is accompanied by significant hearing loss (up to 50-60 dB).
The design features of the lever system allow not only to amplify weak sounds, but also to perform a protective function to a certain extent - to weaken the transmission of strong sounds. With weak sounds, the base of the stirrup vibrates mainly around a vertical axis. With strong sounds, slipping occurs in the incus-malleus joint, mainly with low-frequency tones, as a result of which the movement of the long process of the malleus is limited. Along with this, the base of the stirrup begins to vibrate predominantly in the horizontal plane, which also weakens the transmission of sound energy.
In addition to the eardrum and the auditory ossicles, the inner ear is protected from excess sound energy by contracting the muscles of the tympanic cavity. When the stapes muscle contracts, when the acoustic impedance of the middle ear increases sharply, the sensitivity of the inner ear to sounds of mainly low frequencies decreases to 45 dB. Based on this, there is an opinion that the stapedius muscle protects the inner ear from excess energy of low-frequency sounds (Undrits V.F. et al., 1962; Moroz B.S., 1978)
The function of the tensor tympani muscle remains poorly understood. It is believed to have more to do with ventilating the middle ear and maintaining normal pressure in the tympanic cavity than with protecting the inner ear. Both intraauricular muscles also contract when opening the mouth and swallowing. At this moment, the sensitivity of the cochlea to the perception of low sounds decreases.
The sound-conducting system of the middle ear functions optimally when the air pressure in the tympanic cavity and mastoid cells is equal to atmospheric pressure. Normally, the air pressure in the middle ear system is balanced with the pressure of the external environment; this is achieved thanks to the auditory tube, which, opening into the nasopharynx, provides air flow into the tympanic cavity. However, the continuous absorption of air by the mucous membrane of the tympanic cavity creates a slightly negative pressure in it, which requires constant equalization with atmospheric pressure. In a calm state, the auditory tube is usually closed. It opens when swallowing or yawning as a result of contraction of the muscles of the soft palate (which stretches and elevates the soft palate). When the auditory tube closes as a result of a pathological process, when air does not enter the tympanic cavity, sharply negative pressure occurs. This leads to a decrease in hearing sensitivity, as well as to the transudation of serous fluid from the mucous membrane of the middle ear. Hearing loss in this case, mainly for tones of low and medium frequencies, reaches 20 - 30 dB. Violation of the ventilation function of the auditory tube also affects the intralabyrinthine pressure of the fluids of the inner ear, which in turn impairs the conduction of low-frequency sounds.
Sound waves, causing movement of the labyrinthine fluid, vibrate the main membrane on which the sensitive hair cells of the spiral organ are located. Irritation of hair cells is accompanied by a nerve impulse entering the spiral ganglion, and then along the auditory nerve to the central parts of the analyzer.
The process of obtaining sound information includes the perception, transmission and interpretation of sound. The ear captures and transforms auditory waves into nerve impulses, which are received and interpreted by the brain.
There is a lot in the ear that is not visible to the eye. What we observe is only part of the outer ear - a fleshy-cartilaginous outgrowth, in other words, the auricle. The outer ear consists of the concha and the ear canal, ending at the eardrum, which provides communication between the outer and middle ear, where the hearing mechanism is located.
Auricle directs sound waves into the ear canal, similar to how the ancient Eustachian trumpet directed sound into the pinna. The channel amplifies sound waves and directs them to eardrum. Sound waves hitting the eardrum cause vibrations that are transmitted through three small auditory bones: the malleus, the incus and the stapes. They vibrate in turn, transmitting sound waves through the middle ear. The innermost of these bones, the stapes, is the smallest bone in the body.
Stapes, vibrating, strikes a membrane called the oval window. Sound waves travel through it to the inner ear.
What happens in the inner ear?
There is a sensory part of the auditory process. Inner ear consists of two main parts: the labyrinth and the snail. The part, which starts at the oval window and curves like a real cochlea, acts as a translator, turning sound vibrations into electrical impulses that can be transmitted to the brain.
How does a snail work?Snail filled with liquid, in which the basilar (main) membrane seems to be suspended, resembling a rubber band, attached at its ends to the walls. The membrane is covered with thousands of tiny hairs. At the base of these hairs are small nerve cells. When the vibrations of the stapes touch the oval window, the fluid and hairs begin to move. The movement of the hairs stimulates nerve cells, which send a message, in the form of an electrical impulse, to the brain through the auditory, or acoustic, nerve.
Labyrinth is a group of three interconnected semicircular canals that control the sense of balance. Each channel is filled with liquid and located at right angles to the other two. So, no matter how you move your head, one or more channels record that movement and transmit information to the brain.
If you have ever had a cold in your ear or blown your nose too much, so that your ear “clicks”, then you have a guess that the ear is somehow connected with the throat and nose. And that's true. Eustachian tube directly connects the middle ear to the oral cavity. Its role is to allow air into the middle ear, balancing the pressure on both sides of the eardrum.
Impairments and disorders in any part of the ear can impair hearing if they affect the passage and interpretation of sound vibrations.
How does the ear work?
Let's trace the path of the sound wave. It enters the ear through the pinna and is directed through the auditory canal. If the concha is deformed or the canal is blocked, the path of sound to the eardrum is hampered and hearing ability is reduced. If the sound wave successfully reaches the eardrum, but it is damaged, the sound may not reach the auditory ossicles.
Any disorder that prevents the ossicles from vibrating will prevent sound from reaching the inner ear. In the inner ear, sound waves cause fluid to pulsate, moving tiny hairs in the cochlea. Damage to the hairs or the nerve cells to which they are connected will prevent the sound vibrations from being converted into electrical vibrations. But when the sound has successfully turned into an electrical impulse, it still has to reach the brain. It is clear that damage to the auditory nerve or brain will affect the ability to hear.
Why do such disorders and damage occur?
There are many reasons, we will discuss them later. But the most common culprits are foreign objects in the ear, infections, ear diseases, other diseases that cause complications in the ears, head injuries, ototoxic (i.e. poisonous to the ear) substances, changes in atmospheric pressure, noise, age-related degeneration. All of this causes two main types of hearing loss.
The sense of hearing is one of the most important in human life. Hearing and speech together constitute an important means of communication between people and serve as the basis for relationships between people in society. Hearing loss can lead to disturbances in a person's behavior. Deaf children cannot learn full speech.
With the help of hearing, a person picks up various sounds that signal what is happening in the outside world, the sounds of the nature around us - the rustling of the forest, the singing of birds, the sounds of the sea, as well as various pieces of music. With the help of hearing, the perception of the world becomes brighter and richer.
The ear and its function. Sound, or sound wave, is an alternating rarefaction and condensation of air, spreading in all directions from the sound source. And the source of sound can be any oscillating body. Sound vibrations are perceived by our hearing organ.
The organ of hearing is very complex and consists of the outer, middle and inner ear. The outer ear consists of the pinna and the auditory canal. The ears of many animals can move. This helps the animal to detect where even the quietest sound is coming from. The human ears also serve to determine the direction of sound, although they are not mobile. The auditory canal connects the outer ear with the next section - the middle ear.
The auditory canal is blocked at the inner end by a tightly stretched eardrum. A sound wave hitting the eardrum causes it to vibrate and vibrate. The higher the sound, the higher the sound, the higher the vibration frequency of the eardrum. The stronger the sound, the more the membrane vibrates. But if the sound is very weak, barely audible, then these vibrations are very small. The minimum audibility of a trained ear is almost on the border of those vibrations that are created by the random movement of air molecules. This means that the human ear is a unique hearing device in terms of sensitivity.
Behind the eardrum lies the air-filled cavity of the middle ear. This cavity is connected to the nasopharynx by a narrow passage - the auditory tube. When swallowing, air is exchanged between the pharynx and the middle ear. A change in outside air pressure, for example on an airplane, causes an unpleasant sensation - “stuffy ears”. It is explained by the deflection of the eardrum due to the difference between atmospheric pressure and pressure in the middle ear cavity. When swallowing, the auditory tube opens and the pressure on both sides of the eardrum is equalized.
In the middle ear there are three small bones connected in series: the malleus, the incus and the stirrup. The malleus, connected to the eardrum, transmits its vibrations first to the anvil, and then the enhanced vibrations are transmitted to the stirrup. In the plate separating the cavity of the middle ear from the cavity of the inner ear, there are two windows covered with thin membranes. One window is oval, a stirrup “knocks” on it, the other is round.
 |
Behind the middle ear begins the inner ear. It is located deep in the temporal bone of the skull. The inner ear is a system of labyrinths and convoluted canals filled with fluid. There are two organs in the labyrinth: the organ of hearing - the cochlea and the organ of balance - the vestibular apparatus. The cochlea is a spirally twisted bone canal that has two and a half turns in humans. Vibrations of the membrane of the oval window are transmitted to the fluid filling the inner ear. And it, in turn, begins to oscillate with the same frequency. Vibrating, the liquid irritates the auditory receptors located in the cochlea. The cochlear canal is divided in half along its entire length by a membranous septum. Part of this partition consists of a thin membrane - a membrane. On the membrane there are perceptive cells - auditory receptors. Fluctuations in the fluid filling the cochlea irritate individual auditory receptors. They generate impulses that are transmitted along the auditory nerve to the brain. The diagram shows all the sequential processes of converting a sound wave into a nervous signal. Auditory perception. The brain distinguishes between the strength, height and nature of sound, and its location in space. We hear with both ears, and this is of great importance in determining the direction of sound. If sound waves arrive simultaneously in both ears, then we perceive the sound in the middle (front and back). If sound waves arrive a little earlier in one ear than in the other, then we perceive sound either on the right or on the left. |
TESTS on the topic “NERVOUS SYSTEM”
REFLEXES
In the tests, choose one correct answer:
1. Constriction of the pupil in bright light is a reflex:
a) food;
b) indicative;
c) sexual;
d) protective
2. The respiratory center, which regulates the change of inhalation and exhalation, is located in:
a) medulla oblongata;
b) midbrain;
c) diencephalon;
d) cerebellum.
3. The cry of a cat in March is:
a) food reflex;
b) protective reflex;
c) orientation reflex;
d) sexual reflex.
4. When drunkenness gait becomes unsteady. This indicates defeat:
a) hearts;
b) muscle tissue;
c) muscle vessels;
d) nervous system.
5. Salivation when seeing meat is:
a) protective reflex;
b) food reflex;
c) defensive reflex;
d) orientation reflex.
6. During sleep, brain activity:
a) completely absent;
b) is being rebuilt;
c) decreases;
d) increases.
7. Signals travel through interneurons:
a) to the muscles;
b) from receptors;
c) to the walls of the stomach;
d) from neuron to neuron.
8. Signals travel through sensitive neurons:
a) from the brain to the muscles;
b) from muscles to brain;
c) from the sense organs to the neuron;
d) from the brain to the walls of the stomach.
Answers: 1-d, 2-a, 3-b, 4-d, 5-b, 6-c, 7-d, 8-c
SPINAL CORD
9. Average length spinal cord in an adult about:
A. 20 cm B. 150 cm
B. 95 cm D. 45 cm
10. The spinal cord consists of:
A. 20-21 segments B. 31-32 segments
B. 42-43 segments D. 16-17 segments
11. Where are the spinal cord pathways located?
A. In the white matterB. In the central canal
B. In gray matterD. In the mixed spinal nerve
12. Function of the gray matter of the spinal cord:
A. Secretory B. Supporting
B. Reflex G. Provodnikovaya
13. Where are motor neurons located in the spinal cord?
A. In the dorsal rootB. In the anterior root
B. In the median sulcusD. In the central canal
14. What corresponds to the conductive function of the spinal cord
A. Extension of the limbsB. Knee reflex
B. Transmission of nerve impulses from the brain
D. Transmission of a nerve impulse from the spinal cord to the brain.
15. Which neuron processes transmit impulses from the neuron body to the organs?
A. Axon B. Dendrites
B. Axon and dendrites
16. What function do sensory neurons perform?
A. Transmits impulses from the brain to the organs
B.Transmits impulses from organs to the brain
B. Transmits impulses inside the brain from one neuron to another
D. Supportive and nutritional function within the brain
17. What function do motor neurons perform?
(See answers to question 16.)
18. What function do interneurons perform?
A. Nutritional function
B. Conduct impulses inside the brain from one neuron to another
B. Support function
Answers: 9-d, 10-c, 11-a, 12-b, 13-c, 14-c, 15-a, 16-b, 17-a, 18-b
card number 2
Execute test. Choose one correct answer
1. Nervous system performs the following functions:
A. Transports nutrients
B.Carries out humoral regulation
B. Connects the body with the external environment
D. Ensures coordinated activities of bodies
2.
The nervous system consists of nerve cells called:
A. Axons
B. Dendrites
B. Neurons
G Mediators
3. According to function, the entire nervous system is divided into:
A. Somatic and vegetative (autonomous)
B. Sympathetic and parasympathetic
B. Central and peripheral
G. Peripheral and somatic
4. The autonomic nervous system regulates:
A. Movement of skeletal muscles
B. Vascular tone
B. The work of internal organs
D Contractions of the intestinal walls
5. Gray matter is:
A. Cluster of neuron cell bodies
B. Accumulation of long processes of neurons
B. Nerve fibers neurons
D. Choroid
6. Nerve is:
A. Bundles of nerve fibers outside the central nervous system
B.Axon of one neuron
B. Clusters of neuron cell bodies
G. Spinal cord pathways
7. Synapse is:
A. The area of contact of nerve cells with each other or with tissues
B.Substance released due to the action of a nerve impulse
B. Termination of sensory nerve fibers
G."Energy station" of the cell
8. Properties of nervous tissue:
A. Excitability and contractility
B. Excitability and conductivity
B. Contractility
D. Excitability only
9. The peripheral nervous system does not include:
A. Nerves
B. Ganglia
B. Spinal cord
D. Nerve endings
Answers: 1-d, 2-b, 3-c, 4-b, 5-a, 6-a, 7-a, 8-b, 9-c
Card 3.
I) Find a match.
1) Match the part (division) of the nervous system and its functions:
1. Cerebral cortexA) Regulates the functioning of internal organs
2. Spinal cord B) Ensures the implementation of higher mental functions
3. Autonomic nervous system
4. Somatic nervous systemB) Regulates the functioning of skeletal muscles
D) Ensures the implementation of simple reflexes
2) Match the neurons and their location:
1. SensitiveA) Anterior horns of the gray matter of the spinal cord;
2. Motor B) Posterior horns of the gray matter of the spinal cord;
3. Insert B) Lateral horns of the gray matter of the spinal cord;
4. Vegetative D) Spinal ganglia.
3) Correlate the sensitive and motor areas of the cerebral cortex and their location:
1. Visual A) frontal lobe
2. Auditory B) parietal lobe
3. Musculocutaneous B) occipital lobe
4. Flavor D) temporal lobe.
5. Olfactory
II) Prepare short answers to the questions:
1. The structure of nervous tissue.
2. What is a reflex? Name the stages of the reflex.
3. Reflex arc, types of reflex arcs.
4. Divisions of the nervous system.
5. Functions of the spinal cord.
6. Sections of the brain and their significance.
7. Peripheral nervous system. Types of nerves.
8. Comparative characteristics somatic and autonomic nervous system.
brain
card 4.
1. Average weight of the adult brain:
A) less 950 g;
B) 950-1100 g;
B) 1100 – 2000 g
2. The human brain consists of:
A) brain stem and hemispheres;
B) cerebellum and cerebral hemispheres;
B) brainstem, cerebellum, cerebral hemispheres.
3. The medulla oblongata is a continuation of:
A) midbrain;
B) spinal cord;
B) diencephalon.
4. In the brain, the hemispheres and cortex have:
A) midbrain and cerebral hemispheres
B) cerebellum and diencephalon;
B) cerebral hemispheres and cerebellum.
5. Which parts of the brain belong to the brain stem:
A) midbrain;
B) medulla oblongata;
B) cerebellum;
D) diencephalon;
D) bridge
6. Which part of the brain is like a continuation of the spinal cord in the cranial cavity:
A) midbrain;
B) medulla oblongata;
B) diencephalon
7. Which part of the brain contains motor reflex centers that ensure the rotation of the eyeballs:
A) bridge;
B) midbrain;
B) diencephalon.
1. Constriction of the pupil in bright light is a reflex:
a) food;
b) indicative;
c) sexual;
d) protective
2. The respiratory center, which regulates the change of inhalation and exhalation, is located in:
a) medulla oblongata;
b) midbrain;
c) diencephalon;
d) cerebellum.
3. The cry of a cat in March is:
a) food reflex;
b) protective reflex;
c) orientation reflex;
d) sexual reflex.
4. When intoxicated, the gait becomes unstable. This indicates defeat:
a) hearts;
b) muscle tissue;
c) muscle vessels;
d) nervous system.
5. Salivation when seeing meat is:
a) protective reflex;
b) food reflex;
c) defensive reflex;
d) orientation reflex.
6. During sleep, brain activity:
a) completely absent;
b) is being rebuilt;
c) decreases;
d) increases.
7. Signals travel through interneurons:
a) to the muscles;
b) from receptors;
c) to the walls of the stomach;
d) from neuron to neuron.
8. Signals travel through sensitive neurons:
a) from the brain to the muscles;
b) from muscles to brain;
c) from the sense organs to the neuron;
d) from the brain to the walls of the stomach.
Answers: 1-d, 2-a, 3-b, 4-d, 5-b, 6-c, 7-d, 8-c
12. Function of the gray matter of the spinal cord:
A. Secretory B. Supporting
B. Reflex G. Conductive
14. What corresponds to the conductive function of the spinal cord
A. Extension of the limbs B. Knee reflex
B. Transmission of nerve impulses from the brain
D. Transmission of a nerve impulse from the spinal cord to the brain.
15. Which neuron processes transmit impulses from the neuron body to the organs?
A. Axon B. Dendrites
B. Axon and dendrites
16. What function do sensory neurons perform?
A. Transmit impulses from the brain to the organs
B. Transmit impulses from organs to the brain
B. Transmit impulses inside the brain from one neuron to another
D. Supportive and nutritional function within the brain
17. What function do motor neurons perform?
(See answers to question 16.)
A. Nutritional function
B. Conduct impulses inside the brain from one neuron to another
B. Support function
Card 3.
I) Find a match.
1) Correlate the part (division) of the nervous system and its functions:
1. Cerebral cortex A) Regulates the functioning of internal organs
2. Spinal cord B) Ensures the implementation of higher mental functions
3. Autonomic nervous system
4. Somatic nervous system B) Regulates the work of skeletal muscles
D) Ensures the implementation of simple reflexes
2) Match the neurons and their location:
1. Sensitive A) Anterior horns of the gray matter of the spinal cord;
2. Motor B) Posterior horns of the gray matter of the spinal cord;
3. Intercalary B) Lateral horns of the gray matter of the spinal cord;
4. Autonomic D) Spinal ganglia.
3) Correlate the sensitive and motor zones of the cerebral cortex and their location:
1. Visual A) frontal lobe
2. Auditory B) parietal lobe
3. Musculocutaneous B) occipital lobe
4. Gustatory D) temporal lobe.
5. Olfactory
II) Prepare short answers to the questions:
1. The structure of nervous tissue.
2. What is a reflex? Name the stages of the reflex.
3. Reflex arc, types of reflex arcs.
4. Divisions of the nervous system.
6. Sections of the brain and their significance.
7. Peripheral nervous system. Types of nerves.
8. Comparative characteristics of the somatic and autonomic nervous systems.
BRAIN
card 1.
1. Average weight of the adult brain:
A) less than 950 g;
B) 950-1100 g;
B) 1100 – 2000 g
2. The human brain consists of:
A) brain stem and hemispheres;
B) cerebellum and cerebral hemispheres;
B) brainstem, cerebellum, cerebral hemispheres.
3. The medulla oblongata is a continuation of:
A) midbrain;
B) spinal cord;
B) diencephalon.
4. In the brain, the hemispheres and cortex have:
A) midbrain and cerebral hemispheres
B) cerebellum and diencephalon;
B) cerebral hemispheres and cerebellum.
5. Which parts of the brain belong to the brain stem:
A) midbrain;
B) medulla oblongata;
B) cerebellum;
D) diencephalon;
D) bridge
6. Which part of the brain is like a continuation of the spinal cord in the cranial cavity:
A) midbrain;
B) medulla oblongata;
B) diencephalon
7. Which part of the brain contains motor reflex centers that ensure the rotation of the eyeballs:
A) bridge;
B) midbrain;
B) diencephalon.
Answers: 9-d, 10-c, 11-a, 12-b, 13-c, 14-c, 15-a, 16-b, 17-a, 18-b
Card No. 2
Complete the test task. Choose one correct answer
1. The nervous system performs the following functions:
A. Transports nutrients
B. Carries out humoral regulation
B. Connects the body with the external environment
D. Ensures coordinated activities of bodies
2. The nervous system consists of nerve cells, which are called:
A. Axons
B. Dendrites
B. Neurons
G Mediators
3. According to function, the entire nervous system is divided into:
A. Somatic and vegetative (autonomous)
B. Sympathetic and parasympathetic
B. Central and peripheral
G. Peripheral and somatic
4. The autonomic nervous system regulates:
A. Movement of skeletal muscles
B. Vascular tone
B. The work of internal organs
D Contractions of the intestinal walls
5. Gray matter is:
A. Cluster of neuron cell bodies
B. Accumulation of long processes of neurons
B. Nerve fibers of neurons
D. Choroid
6. Nerve is:
A. Bundles of nerve fibers outside the central nervous system
B. Axon of one neuron
B. Clusters of neuron cell bodies
D. Spinal cord pathways
7. Synapse is:
A. The area of contact of nerve cells with each other or with tissues
B. Substance released due to the action of a nerve impulse
B. Termination of sensory nerve fibers
D. "Energy station" of the cell
8. Property of nervous tissue:
A. Excitability and contractility
B. Excitability and conductivity
B. Contractility
D. Excitability only
9. The peripheral nervous system does not include:
B. Ganglia
B. Spinal cord
D. Nerve endings
Answers: 1-d, 2-b, 3-c, 4-b, 5-a, 6-a, 7-a, 8-b, 9-c
Option 1
1. The peripheral nervous system includes:
1) 31 pairs of spinal nerves 2) 12 pairs of cranial nerves 3) medulla oblongata 4) nerve ganglia around the spine 5) segmental department central system 6) cerebellum 7) nerve ganglia of internal organs 8) pons
window. google_render_ad(); A)1,3,5 B)2,4,6 C)6,7,8 D)1,2,4,7 E)3,5,6,8
2. “Nucleus pallidus” and “corpus striatum” - what are they?
A) components of the gray matter of the cerebral hemispheres
B) gray matter of the cerebellum
C) subcortical region of the brain (hypothalamus)
D) inner layer of the medulla oblongata
E) Varoliev bridge
3. Which answer option correctly names the structure of the gray matter of the spinal cord?
1-pair of front horns 2-pair of rear horns 3-pair of lateral horns
a) motor neurons b) sensory neurons c) autonomic neurons
A) 1a, 2b, 3c B) 1b, 2a, 3c C) 1c, 2b, 3a D) 1a, 2c, 3b E) 1b, 2c, 3a
4. Extend your right arm forward. Use your index finger to touch the tip of your nose. Which part of the brain was involved in this movement, coordinating the activity of the arm muscles and determining the trajectory of movement?
A) spinal cord B) medulla oblongata C) cerebellum D) midbrain
E) cerebral cortex
5. The main speech center is located: 1) in the occipital 2) parietal 3) temporal 4) frontal lobe
A) left hemisphere a) right hemisphere of the brain
A)3-A B)1-A C)2-a D)4-A E)4-a
6.Inflammation of sensory nerve fibers is...
A) ganglitis B) neuritis C) neuralgia D) radiculitis E) myelitis
7. The sensory and motor functions of which human organs are provided by the nerve centers of the thoracic segment of the spinal cord?
A) skin and muscles, starting from the 5th rib of the chest to the bladder, internal
hand surface
C) skin and muscles of the head, neck, chest, outer surface of the arms
C) skin and muscles of the palm and fingers
D) tissues and organs of the abdominal cavity
E) skin and muscles of the legs and toes
8. Highlight the physical processes that regulate the thalamus and hypothalamus of the brain:
1) perception of external and internal stimuli through the senses 2) conduction of nerve
impulses to the medulla oblongata and spinal cord 3) regulation of breathing and cardiac activity
4) constancy of body temperature 5) ensuring normal metabolism 6) response to hunger
and saturation 7) protective reflexes - blinking, sneezing, coughing 8) juice and salivation
9) regulation of the activity of the pituitary gland
A)1,4,5,6,9 B)2,3,5,8 C)1,3,5,7 D)2,4,6,8 E)6,7,8
9.Location of the sensitive center of the skin...
A) occipital part of the cerebral cortex B) lower internal part of the frontal part
C) temporal part of the cerebral cortex D) anterior central gyrus of the parietal
E) in the posterior central gyrus of the vertex
10.What develops when the nerve cells of the spinal cord are damaged and the sensory and motor functions of tissues and organs are impaired?
A) hematoma B) neurosis C) paralysis D) aneurysm E) stroke
11. When what nerve centers are damaged, the perception of external and internal stimuli is disrupted?
A) midbrain B) pons C) thalamus D) hypothalamus E) C, D
12.Which receptor impulses are perceived by the associative zone of the cerebral cortex?
A) sensory organs B) muscles and tendons C) has no connection with tissues and organs of the body
D) skin E) joints and bones
13. In what part and what hemisphere of the cerebral cortex is the center that gives melody to human speech located?
A) temporal right hemisphere B) temporal left hemisphere
C) parietal right hemisphere D) frontal right hemisphere
E) frontal left hemisphere
14.What parts of the nervous system regulate the lower functions of the body?
A) spinal cord, pons B) medulla oblongata, cerebellum
C) midbrain, diencephalon D) A, B, C
E) cerebral cortex
15.Which part of the brain is associated with the formation of biologically active substances and the implementation of humoral regulation? Name that department.
A) intermediate B) middle C) medulla D) cerebellum E) forebrain
16. How many parts does the reflex arc consist of?
A) two B) five C) three D) four E) six
17.Which answer correctly indicates the reflexes of the spinal cord?
A) smell, digestion, breathing B) urination, pupil dilation
C) chewing, coughing, salivation D) movement, reading, speaking, learning
E) cry, sense of smell, coordination of movement
18. Determine which organs are controlled by the autonomic nervous system?
A) heart, intestines, endocrine glands, chest muscle metabolism
B) cardiac and neck muscles
C) kidneys, lungs, eye muscles
D) pancreas, chest muscles
E) salivary glands, liver, back muscles
19. Encephalitis is inflammation...
A) membranes surrounding the brain B) brain tissue
C) the membrane surrounding the spinal cord D) the tissue of the spinal cord
E) nerve cells of the spinal cord
20. In what part of the brain is the nerve center located that moves the eye?
A) medulla oblongata B) diencephalon C) midbrain
D) cerebellum E) pons
TESTS ON THE TOPIC: “NERVOUS SYSTEM” Option 2
window. google_render_ad(); 1. What reflexes are provided by the diencephalon: 1) sensation of cold 2) overheating of the body 3) desire to sleep 4) increase in blood sugar 5) blinking 6) cough 7) inhalation and exhalation 8) increase in thyroxine 9) thirst
A)1,2,4,5 B)3,4,5,6 C)4,5,6,7 D)6,7,8,9 E)1,2,3,4,8,9
2.Structure of the gray matter of the spinal cord on cross section has the shape of a butterfly and consists of nerve cells. Find out how many horns the gray matter has and what nerve cells are in them.
A) one pair of anterior horns - motor neurons, one pair of posterior horns - sensory neurons
B) one pair of anterior horns - sensory neurons, one pair of posterior horns - motor neurons
C) one pair of anterior horns - motor neurons, one pair of posterior horns - interneurons, one pair of lateral horns - sensory neurons
D) one pair of anterior horns - all types of neurons, one pair of posterior horns - all types of neurons
E) one pair of anterior horns - motor neurons, one pair of posterior horns - which includes the processes of sensory neurons, one pair of lateral horns - motor neurons of the autonomic nervous system
3. What does the gray matter in the thickness of the white matter of the brain consist of?
A) serotonin B) fats, proteins, carbohydrates C) nucleus pallidum, striatum
D) white matter E) axons and dendrites
4.Where is the main speech center located?
A) in the occipital part B) in the hemispheres C) in the temporal part of the left hemisphere
D) in the midbrain E) in the temporal part of the right hemisphere
5. Inflammation of motor nerve fibers is...
6.The centers of the autonomic nervous system are located...
A) in the spinal cord between 1st thoracic and 3rd lumbar segments
B) in the medulla oblongata C) in the midbrain D) A, B, C
E) in the hypothalamus
7.The human somatic nervous system controls...
A) movements B) sense organs C) heart function D) higher nervous activity
E) the work of the stomach
8.What is the sequence of the excitation pathway when a hand is burned? 1) receptor 2) centrifugal neuron
3) centripetal neuron 4) interneuron 5) gray matter of the spinal cord
6) cerebral cortex 7) muscle
A)1,3,4,6 B)1,2,5,6,3 C)2,4,3 D)1,3,4,2,7 E)3,4,2
9. The influence of which nerves causes increased heart rate and constriction of blood vessels?
A) cranial B) sympathetic C) spinal
D) parasympathetic E) somatic
10. Regulation of chewing, swallowing, sneezing, coughing, as well as protective digestive reflexes are associated with...
A) diencephalon B) nuclei of the medulla oblongata and pons
C) midbrain D) cerebral hemispheres of the forebrain
E) cerebellum
11.What is a reflex?
A) the body’s response to impulses sent and controlled by the central nervous system
B) regulation of the activity of the nervous system
C) nervous and humoral activity of the body
D) the influence of the external environment on the nervous system
E) there is no correct answer
12.Where are the digestive centers located and what nerves increase the functioning of the digestive organs?
A) intermediate, parasympathetic B) cerebral cortex, sympathetic
C) brain stem, sympathetic D) brain stem, parasympathetic
E) oblongata, intermediate, parasympathetic
13. Where are the sensitive and motor functions of the fingers provided?
A) brain B) cervical segment of the spinal cord
C) only in the right hemisphere D) in the elbow joint E) A, B
14. What does human mental activity depend on?
2. What makes up the gray matter of the brain?
A) nucleus pallidum and corpus striatum B) corpus pallidus and nucleus striatum
C) cells of the hypothalamus D) gray body, white nucleus
E) stem cells
3. What is the mass of the human medulla oblongata?
A) 100 g B) 10 g C) 70 g D) 7 g E) 1 g
4. Inflammation of neuromuscular fibers is...
A) ganglitis B) neuritis C) neuralgia D) radiculitis E) myositis
5. Why does spinal cord injury lead to paralysis?
A) ascending pathways are destroyed
C) descending pathways are destroyed
C) the dorsal roots of the spinal nerves are damaged
D) the anterior roots of the spinal nerves are damaged
E) the connection between the spinal cord and brain is interrupted
6. Where is the visual area?
A) in the occipital lobe B) in the parietal lobe C) in the temporal lobe
D) in the frontal lobe E) anterior central sulcus
7. What is the reflex arc path of the knee reflex?
A) muscle-receptor-nerve cell-intercalary cell-motor nerve cell
B) receptor-sensitive cell-intercalary cell-motor cell
C) receptor-sensitive nerve fiber - sensitive nerve cell-
interneuron - motor neuron-motor nerve fiber-muscle
D) sensitive neuron - interneuron - motor cell - sensitive
cell - muscle - receptor
E) muscle - receptor - interneuron - motor neuron - sensory cell -
nerve motor fiber - muscle
8. Indicate the main properties of nervous tissue.
A) excitability, contractility B) elasticity, contractility
C) excitability, conductivity D) automation, conductivity
E) automaticity, excitability
9. Motor nerves are...
A) nerves consisting of dendrites B) nerves consisting of axons and dendrites
C) nerves consisting of axons D) nerves consisting of axons of motor neurons
E) all answers are correct
10. Regulation of chewing, swallowing, sucking, as well as protective digestive reflexes are associated with...
A) diencephalon B) midbrain
C) nuclei of the medulla oblongata D) cerebellum
E) the cerebral hemispheres of the forebrain
11. Neuroglia is...
A) disease of the human nervous system
B) part of the spinal cord
C) cells with processes that are not part of the nervous tissue
D) cells that make up the nervous tissue and are located around the neurons of the brain
and spinal cord
E) cells not related to the nervous system
12.Which part of the brain is the higher nervous activity of higher mammals associated with?
A) middle B) dorsal C) oblong D) intermediate E) cerebral hemispheres
13.What is the segmental part of the central nervous system represented by?
A) spinal cord and lower parts of the brain
B) higher nerve centers and the cortical part of the brain
C) hemispheres of the brain
D) brain and spinal cord E) spinal cord and hemispheres
14.Which nervous system regulates the activity of the endocrine glands?
A) somatic B) vegetative C) peripheral D) central E) suprasegmental
15. What function does the white matter of the spinal cord perform?
A) transmission of impulses of the spinal cord and brain B) motor function
C) regulation of the activity of internal organs D) humoral function
E) regulation of respiratory function
16. Specify diseases of the central nervous system.
A) otitis, paratitis B) hepatitis, osteochondrosis C) myelitis, encephalitis
D) heart attack, ischemia E) gastritis, colitis
17. What is the disease characterized by chorea?
A) involuntary sudden movements of the limbs, blinking of the eyes
C) changes in handwriting, unsteady gait D) decreased pain and heat sensitivity
C) depressed mood, weight loss E) mood swings, decreased muscle tone
18.What zones is the surface of the human cerebral cortex divided into, depending on the functions,
performed by cortical cells?
A) sensitive, auditory, visual B) motor, sensitive, olfactory
C) frontal, parietal, temporal, motor D) sensitive, motor, associative
E) sensitive, visual, muscular
19.What is characterized by paralysis resulting from damage to brain tissue?
A) muscle tone of the limb increases and the limb becomes stiff
C) pain appears in the limb, then it becomes paralyzed and hangs like a whip
C) sensitivity and movement of the limb decreases
D) pain in the skin and muscles, trembling of the arms and legs
E) all answers are correct
20.Where are the centers of the somatic nervous system located?
window. google_render_ad(); A) evenly in all parts of the spinal cord and brain
B) in the lower parts of the brain
C) from the first thoracic to the third lumbar segments of the spinal cord
D) in the sacral part of the spinal cord