Psychiatry and narcology. Study of reflexes. Tendon reflexes. II. Deep reflexes: tendon
Skin reflexes of the spinal cord are caused by dashed skin irritation, in response to which a contraction of one or another muscle or group of them occurs. Unlike tendon reflexes, cutaneous reflexes are not congenital. They occur in children different ages(from 5 months to 3 years). Obviously, their formation is largely due to the development of the cerebral cortex and pyramidal pathways. The double circuit of skin reflexes (in the spinal cord and cerebral cortex) is due to the fact that their absence can be caused by damage to both their spinal reflex arc and the pyramidal pathway, which is an essential link in the efferent part of the skin reflex arc.
Skin reflexes include:
Abdominal reflexes. They are caused by rapid stroke irritation of the skin of the abdomen with the blunt end of the needle or the handle of the hammer. The response consists in contraction of the abdominal muscles on the side of the same name. To evoke the upper abdominal reflex, a stroke irritation is applied on the skin parallel to the costal arch, for the middle abdominal reflex - at the level of the navel in the horizontal direction, for the lower abdominal reflex - parallel to the inguinal fold.
This also includes the bone-abdominal reflex described by V. M. Bekhterev, which consists in the fact that when a hammer strikes the edge of the costal arch medially from the nipple line, the abdominal muscles of the corresponding side contract. These deep (periosteal) abdominal reflexes can be used to compare abdominal reflexes on either side.
Cremaster muscle reflex is caused by applying dashed irritation to the skin of the inner surface of the thigh 1-2 cm below the inguinal fold. The response in this case is expressed in pulling the testicle up.
plantar reflex It is caused by a stroke irritation of the sole, in response to which plantar flexion of the fingers follows.
anal reflex caused by a prick of the skin near the anus. In response, its circular muscle contracts.
A special place is occupied by the so-called articular reflexes. By their nature, they belong to deep reflexes, however, they are closer to skin reflexes by their late appearance and dependence on the pyramidal pathways. With the integrity of the spinal reflex arcs of the articular reflexes, their weakening or disappearance is regarded as a sign of damage to the pyramidal tracts. These include the following reflexes.
Mayer's reflex. It is caused by forced flexion of the main phalanx of the III or IV finger of the supinated hand. In this case, flexion of the main one occurs, as well as adduction and extension of the nail phalanx of the thumb.
Reflex Leri. In the position of the supinated hand and bent fingers, vigorous flexion of the fingers and hand in the wrist joint is performed. In this case, there is a reflex flexion of the arm in the elbow joint.
A decrease or absence of skin and articular reflexes, combined with an increase in tendon reflexes and the appearance of pathological ones, is a reliable sign of damage to the pyramidal tracts. It should be borne in mind that abdominal reflexes are often not evoked if the patient has a flabby abdominal wall with complete intact reflex arcs of these reflexes.
An increase in skin reflexes does not play such a role in the clinic as their decrease or absence. An increase in abdominal and plantar reflexes is often found in functional diseases. nervous system, at general increase her excitability. Usually, in these patients, the study of reflexes itself causes a general emotional reaction (trembling of the whole body, screaming, etc.).
Of some importance in the clinic is an increase in the Mayer articular reflex. It is manifested by the fact that the thumb is adducted and opposed with the slightest flexion of the main phalanges of the III and IV fingers, and also by the fact that additional contractions of the flexors of the forearm and deltoid muscle are caused. An increase in the reflex is sometimes observed with frontal localizations of the process, and on the side of the same name to the focus. Often, an increase in the Mayer reflex accompanies the grasping reflex.
The most important tendon reflex in the lower extremities is knee, or patellar. In this reflex, stimulation of the tendon of the quadriceps femoris causes its contraction.
The method of obtaining it is as follows: the patient sits down and crosses his legs, and the examiner strikes the lig with a hammer. patellae proprium. Due to the reflex contraction of the quadriceps femoris muscle, the lower leg swings forward (Fig. 25).
If the patient cannot sit, then the examiner raises the leg at the knee joint so that the lower leg hangs freely, and then strikes the tendon.
The main condition for obtaining a reflex is that all the muscles of the leg are completely relaxed. Relatively often, this condition is not met: the patient keeps the antagonists tense, as a result of which the reflex is not evoked. Then resort to various artificial methods to eliminate this undesirable phenomenon. There are quite a few of these tricks; the most common are the following: the Iendrassik method. The patient crosses his legs and, bending the fingers of both hands with a hook, grabs them for each other and strongly stretches his arms to the sides; the researcher at this time causes a reflex. Shenborn method (Schonbom). The position of the patient is the same. The doctor extends his left hand to him, makes him grab his forearm and squeeze it with both hands, and at this time he himself causes a reflex with his free right hand. Kronig's method. During the study, the patient is forced to take a strong breath and look at the ceiling at this time. Rosenbach's method. Volnoy during the study is forced to read loudly or say something.
Sometimes, if all attempts to evoke a reflex fail, it is enough to make the patient walk around the room for several minutes, after which the reflex is already called (Kroner's method).
The reflex arc of the knee jerk passes at the level of three spinal segments: the 2nd, 3rd and 4th lumbar (L 2 - L 4), with the 4th lumbar playing the main role.
I will ask you to firmly remember the levels of each reflex, since this plays a very important role in the segmental diagnosis of diseases of the spinal cord.
The knee jerk is one of the most constant reflexes. Its absence, especially one-sided, usually indicates an organic disease of the nervous system. Only in the form of a very rare exception can be observed in completely healthy people such areflexia, and it remains doubtful whether they suffered at an early age any disease associated with damage to the reflex arc.
To quantitatively measure the knee reflex, a number of bulky and impractical devices have been built that record on a rotating drum in the form of a curve the swings of the lower leg or the rises of the quadriceps muscle due to its contraction. So far, such an instrumental study has not yielded any special results.
As a rule, every specialist soon develops his own eye, which helps him to distinguish between gradations of reflexes. To designate these gradations, I advise you to use the following designations.
We are speaking - reflex is evoked when in terms of strength he does not represent anything special; live reflex, when there is a moderate increase; reflex increased, when there is undoubtedly a significant increase in the reflex.
A reflex change in the opposite sense is characterized as follows: sluggish reflex when there is a slight decrease in it; reflex is reduced when the weakening of it is very significant; no reflex when it is not possible to call it by any auxiliary methods.
The next most important tendon reflex is Achilles. In it, irritation of the Achilles tendon gives a contraction of the calf muscle.
It is called like this. The freestyle kneels on a chair so that the feet hang over the edge of the chair, and relaxes the muscles if possible. The examiner strikes the Achilles tendon with a hammer, resulting in plantar flexion of the foot (Fig. 26).
In bed, it is best to examine the Achilles reflex with the patient in the prone position. The doctor raises the patient's shin, holding the foot, which leads to a state of slight dorsiflexion. At the same time, the Achilles tendon is somewhat stretched, and a gift is applied along it with a hammer.
When the patient is on his back, the study is somewhat less convenient, since the blow with the hammer has to be done from the bottom up.
The inhibition of this reflex is much less pronounced, and therefore, as a rule, in practice it is not necessary to use any tricks to evoke it.
The Achilles reflex arc passes through the first and second sacral segments (S 1 - S 2), and the main role belongs to the first sacral.
The Achilles reflex is also one of the most constant. Most likely, every healthy person has it, like a knee, and its absence should be considered a pathological phenomenon. Regarding the sometimes observed absence of it in people who are obviously healthy, one can only repeat what I have already said about the knee jerk.
The quantitative characterization of the Achilles reflex with the help of various instruments gives even less than for the knee reflex, and therefore it is best to evaluate it in the way that I already recommended to you when I spoke about the patellar reflex.
On the hands, most often you have to deal with two tendon reflexes - c m. biceps and with m. triceps.
Biceps reflex
It is called like this. the doctor takes the patient by the forearm, bends him at the elbow at an obtuse angle and hits the biceps tendon with a hammer. As a result, a single flexion at the elbow occurs (Figure 27).
This reflex is very constant, but still not the same as the knee and Achilles. Apparently, it can be absent in a certain percentage of cases or, which is practically the same thing, be expressed extremely weakly.
Its reflex arc passes through the fifth and sixth cervical segments (c 5 - C 6).
Triceps reflex consists in the contraction of this muscle from a blow to its tendon.
The way to call it is as follows: the doctor puts the upper limb of the patient on his left hand, bent at the elbow at an obtuse angle, and hits the tendon of the triceps muscle in the lowest part of the shoulder with a hammer. At the moment of impact, a single extension at the elbow occurs (Fig. 28).
With regard to this reflex, as well as the previous one, it can be said that it is very frequent, but apparently not absolutely constant or may be extremely weakly expressed in a certain percentage of cases.
Its reflex arc passes through the sixth and seventh cervical segments (C 6 - C 7).
On the head, the most popular tendon reflex is reflex with m. masseter.
It is called like this: the patient is asked to open his mouth slightly, put the end of a wooden spatula on his lower jaw teeth, and hold the other end with his left hand. Then the spatula, like a bridge, is hit with a hammer. The mouth is closed.
You can cause the same reflex by hitting the hammer on the chin or at the place of attachment of the upper end of the masticatory muscle on the zygomatic bone.
reflexes of the spinal cord.
The reflexes of the spinal cord are quite simple. Suprasegmental reflexes, along with segmental ones, are carried out only with the help of the cervical region.
Reflex reactions of the spinal cord depend on the strength of stimulation, the area of the irritated reflexogenic zone, the speed of conduction along the afferent and efferent fibers, and, finally, on the influence of the brain. The strength and duration of spinal cord reflexes increase with repetition of stimulation. (summation).
Own reflex activity of the spinal cord is carried out by segmental reflex arcs. From receptive field reflex information about the stimulus along the sensitive fiber of the neuron reaches the spinal ganglion. Then, along the central fiber of the same neuron through the posterior root, it goes directly to the motor neuron of the anterior horn, the axon of which approaches the muscle. This forms a monosynaptic reflex arc, which has one synapse between the afferent neuron of the spinal ganglion and the motor neuron of the anterior horn.
Other spinal reflexes are realized with the participation of interneurons of the posterior horn or the intermediate region of the spinal cord. As a result, there polysynaptic reflex arcs.
The reflexes of the spinal cord can be divided into two groups according to the following signs. First, according to the receptors, the irritation of which causes a reflex: proprioceptive, visceroreceptive and skin reflexes. The latter are protective. Visceroreceptive reflexes arise from interoreceptors (receptors of internal organs) and are manifested in contractions of the muscles of the anterior abdominal wall, chest and back extensors.
Reflexes arising from proprioreceptors are involved in the formation of the act of walking and the regulation of muscle tone.
Features of muscle and tendon receptors, role in the formation of tendon reflexes.
tendon reflexes are caused by a light blow to the tendon and are manifested by a sharp contraction of the muscle attached to this tendon. The sensory stimulus for the occurrence of tendon reflexes is the stretching of the muscle at the moment of impact on its tendon, while the muscle should not strain, so as not to prevent stretching.
There are two types of proprioceptors - muscle (muscle spindles) and tendon (Golgi receptors).
muscle spindles(muscle receptors) - are located in small muscle fibers surrounded by a capsule of connective tissue, are parallel to the skeletal muscle. The capsules are called muscle spindles, and the muscle fibers enclosed in them - intrafusal(fusus - spindle). Muscle spindles with their ends are attached to the connective tissue sheath (perimysium) of the bundle extrafusal muscle fibers with tendon-like strips of connective tissue 0.5-1 mm long. Intrafusal muscle fibers are much thinner and shorter than the rest, i.e. extrafusal, forming the main muscle mass and its contractions. The length of the intrafusal muscle fibers is 4-7 mm, the thickness is 15-30 microns. The length of extrafusal muscle fibers is from a few millimeters to many centimeters, the thickness is 10-100 microns. Around the middle part of the muscle spindle wraps several times the end of one afferent fiber. Closer to the ends of the muscle spindle, motor nerve endings, which are axons of the y-motoneurons of the spinal cord, approach. Their impulsation causes contraction of intrafusal muscle fibers (receptor muscle fibers).
tendon receptors (Golgi receptors)) are enclosed in a connective tissue capsule, localized in the tendons of skeletal muscles, near the tendon-muscle junction. Receptors are unmyelinated endings thick myelin afferent fiber (having approached the capsule of the Golgi receptors, this fiber loses its myelin sheath and is divided into several endings). Tendon receptors are attached sequentially relative to the skeletal muscle, which ensures their irritation when the tendon is pulled.
The mechanism of the tendon reflex.
With an increase in the length of the muscle, the intrafusal fibers stretch, since they are located parallel to the skeletal muscle, and then in the proprioreceptors ( muscle spindles) there is a receptor potential, and after it and action potential. (The tensile strain of the intrafusal muscle fibers serves as an irritant for the onset of PD). The resulting action potentials propagate along the axon of the primary sensory neuron located in the spinal ganglion. As part of the posterior root, the afferent fibers of this neuron enter the spinal cord and terminate directly on the motor neurons, forming monosynaptic reflex arc.
Under natural conditions, muscle lengthening occurs when the muscle relaxes, when the muscle relaxes (lengthens), muscle receptors also stretch, which and leads to their excitement.
At the moment of impact on the tendon of the muscle, a stretch of the muscle also occurs. When stretching (lengthening) the muscles, proprioceptors are excited - muscle spindles, as indicated above.
Impulses from muscle receptors excite the neurons of their center and inhibit the neurons of the antagonist center.
Tendon receptors are attached sequentially relative to the skeletal muscle, which ensures their stimulation when the tendon is pulled (the tendon is pulled when the muscle contracts).
Therefore, tendon receptors send information to the brain that the muscle is contracted (tension and tendon), and muscle receptors that the muscle is relaxed and lengthened. Impulses from tendon receptors inhibit the neurons of their center and excite the neurons of the antagonist center (in flexor muscles, this excitation is less pronounced).
Tendon reflexes are a special case of stretch reflexes, which are a physiological mechanism for regulating muscle length. When a muscle is rapidly stretched, phasic reflex in the form of a quick response muscle contraction, and with slow stretching - tonic reflex to maintain the same length of the muscle with constant stretching. Tonic reflexes are necessary to maintain muscle tone, by which is meant resistance to gravity, stretching the muscles - extensors. Changes in muscle tone allow you to hold and move the load, maintain balance when the body deviates forward, backward or to the side.
It is advisable to combine spinal reflexes by organs.
A. Reflexes of the limbs. If we take the nature of the response as a unifying feature of limb reflexes, then all of them can be combined into four groups: flexion, extensor, rhythmic and postural reflexes.
1. Flexion reflexes of the limbs (phase and tonic). Phase reflexes are a single flexion of a limb with a single irritation of the skin or proprioreceptors. Simultaneously with the excitation of the motor neurons of the flexor muscles, reciprocal inhibition of the motor neurons of the extensor muscles occurs. Reflexes arising from skin receptors are polysynaptic, they have a protective value. For example, immersing the foot of a spinal frog suspended on a hook in a weak solution of sulfuric acid, or pinching the skin of a limb with tweezers causes the limb to withdraw due to flexion at the knee joint, and with stronger irritation, also in the hip joint.
Phase reflexes from proprioreceptors are involved in the formation of the act of walking. According to the severity of phase flexion and extensor reflexes, the state of excitability of the central nervous system and its possible violations are determined. Several flexion phasic reflexes are examined in the clinic:
elbow and Achilles - proprioceptive reflexes, plantar - skin reflex. Elbow reflex expressed in flexion of the arm in the elbow joint, it occurs when the hammer strikes the tendon m. biceps brachii (when the reflex is called, the arm should be slightly bent at the elbow joint), its arc closes in the 5-6th cervical segments of the spinal cord.
Achilles (heel) the reflex is expressed in plantar flexion of the foot as a result of contraction of the triceps muscle of the lower leg, occurs when the hammer strikes the Achilles tendon, the reflex arc closes at the level of the sacral segments.
plantar reflex- flexion of the foot and fingers with stroke stimulation of the sole, the reflex arc also closes at the level of the first sacrum. segments.
The tonic contraction of the skeletal muscles is the background for all motor acts carried out with the help of phasic muscle contractions and ensures the preservation of the posture.
2. Extension reflexes of the limbs, like flexion, there are phasic and tonic, arise from the proprioreceptors of the extensor muscles, are monosynaptic. Phase reflexes arise in response to a single stimulation of muscle receptors, for example, when the tendon of the quadriceps muscle is struck below the patella. In this case, a knee extensor reflex is observed due to contraction of the quadriceps muscle (the motor neurons of the flexor muscles during the extensor reflex are inhibited - postsynaptic reciprocal inhibition with the help of Renshaw intercalary inhibitory cells). The reflex arc of the knee jerk closes in the 2nd-4th lumbar segments. Phasic extensor reflexes, like flexion reflexes, are involved in the formation of the act of walking.
Tonic extensor reflexes are a prolonged contraction of the extensor muscles during prolonged stretching of their tendons. Their role is to maintain posture. In the standing position, tonic contraction of the extensor muscles prevents flexion of the lower extremities and maintains an upright natural posture. The tonic contraction of the back muscles keeps the torso in an upright position, providing a person's posture. Tonic reflexes to muscle stretch (flexors and extensors) are also called myotatic.
Postural reflexes of the limbs- redistribution of muscle tone, which occurs when the position of the body or its individual parts changes. Postural reflexes are carried out with the participation of various parts of the central nervous system. At the level of the spinal cord, cervical postural reflexes are closed, the presence of which was established by the Dutch physiologist R. Magnus (1924) in special experiments on a cat. The reflex is aimed at maintaining the posture, which can be disturbed due to a change in the position of the center of gravity after turning (tilting) the head. The center of gravity shifts in the direction of head rotation - it is on this side that the tone of the extensor muscles of both limbs increases
4. Rhythmic reflexes - repeated repeated flexion and extension of the limbs (reflexes of rubbing, scratching and stepping reflex). The rubbing reflex consists in the fact that after lubricating the skin of the thigh with an acid solution, the spinal frog (a frog whose brain has been removed) repeatedly rubs this area - it tries to free itself from the irritant. A slight irritation of the skin of the lateral surface of the dog's body causes scratching of this area with the hind limb.
B. Abdominal reflexes - upper, middle and lower. All of them are caused by dashed, irritation of the skin of the abdomen, expressed in the reduction of the corresponding sections of the muscles of the abdominal wall; These are protective reflexes. To call the upper abdominal reflex, irritation is applied in parallel | the lower ribs directly below them, the arc of the reflex closes at the level of the thoracic segments of the spinal cord. The middle abdominal reflex is caused by irritation at the level of the navel (horizontally), the arc of the reflex closes at the level of ThIX-Thx. To obtain a lower abdominal reflex, irritation is applied parallel to the inguinal fold (next to it), the arc of the reflex closes at the level of ThXi-ThXM.
B. Reflexes of the pelvic organs. The cremasteric (testicular) reflex consists in the contraction of m. cremaster and lifting the scrotum in response to a dashed irritation of the upper inner surface of the skin of the thigh (skin reflex), this is also a protective reflex; The anal reflex is expressed in the contraction of the external sphincter of the rectum in response to a dashed irritation or prick of the skin near the anus, the arc of the reflex closes at the level of SM-Sv.
THE MECHANISM OF THE STEP REFLEX Locomotion is a set of coordinated movements with the help of which a person actively moves in space.
The movements performed by each leg alternately represent an alternation of two phases:
1) Swing in which the leg bends and comes off the floor
2) An emphasis at which the leg touches the floor and unbends.
At the same time, the movements of the legs are synchronized so that one of them is in the swing phase and the other is in the stop.
The reflex can last for hours, as the influence of the cerebral cortex is eliminated. Alternate contraction and relaxation of the flexor and extensor muscles is carried out as a result of the interaction of the processes of excitation and inhibition in the corresponding centers of the spinal cord under the influence of impulses entering the brain from proprioreceptors. Special Role proprioceptors in the implementation of the stepping reflex is determined by their location.
The element of the stepping reflex - alternate contraction and relaxation of the skeletal muscle under the influence of impulses from proprioreceptors entering its center, is carried out as follows:
When a muscle (flexor or extensor) is relaxed and lengthened, muscle spindles are excited, impulses from them go to their a-motoneurons of the spinal cord and excite them.
As soon as the muscle has contracted, the excitation of the muscle spindles stops or is greatly weakened (they are no longer stretched), tendon receptors begin to be excited. Impulses from the latter also come first to their center in the spinal cord. but to Renshaw's brake cells.
Excitation of inhibitory cells causes inhibition of a-motoneurons of the same skeletal muscle, as a result of which it relaxes. However, its relaxation (lengthening) leads again to the excitation of muscle spindles and a-motor neurons - the muscle contracts again. As a result of its contraction, tendon receptors and inhibitory cells in the spinal cord are excited, which leads to another relaxation of the skeletal muscle, and so on.
The muscle alternately contracts and relaxes as a result of the receipt of impulses from its own receptors to its motor neurons. The described processes apply equally to the flexor and extensor muscles, while relaxation of the skeletal muscle triggers the mechanisms of its contraction, and contraction of the skeletal muscle activates the mechanisms that relax the muscle. To ensure alternate flexion and extension of the limbs during the stepping reflex, the flexor and extensor muscles must contract and relax sequentially one after another, which is achieved by inhibiting the antagonist center when the agonist center is excited, moreover, if the flexors are contracted on one leg, on the other leg the extensors contract, which is ensured by the supply of afferent impulses from muscle and tendon receptors and by alternate excitation and inhibition of the flexor and extensor centers. Stepping coordinated movements are possible in the absence of reverse afferentation from proprioreceptors. They are carried out with the help of intersegmental connections at the level of the spinal cord. The presence of intersegmental connections at the level of the spinal cord is also evidenced by the fact that all four limbs are involved in the stepping reflex with sufficiently long and strong stimulation of one limb with intact afferent pathways.
Regulation of muscle tone
In some cases, with injuries in humans, a complete intersection of the spinal cord occurs. In experiments on animals, this is reproduced to study the influence of the overlying sections of the central nervous system on the underlying ones. After complete transection of the spinal cord, spinal shock(shock-blow), muscular
atony and lack of reflexes. Disturbance of reflex activity after crossing the spinal cord in different animals lasts for different times. spinal shock in
frogs lasts several minutes, in dogs - several days, in humans - about 2 months.
main reason spinal shock is to turn off the influence of the overlying sections of the central nervous system on the spinal cord (repeated transection of the spinal cord below the first re-shock does not cause).
After the disappearance of the spinal shock, the tone of the muscles innervated by the segments
of the spinal cord, which are below the transection (damage), rises sharply.
Flexion and extensor reflexes of the spinal cord are enhanced.
Hypertonicity has a reflex nature, it develops as a result of afferent impulses from muscle receptors.
Under normal conditions, the activity of the spinal cord is controlled by the overlying departments. CNS by impulsing to all its nerve elements and receiving back afferentation from all organs and tissues.
Within a few hours or weeks, the excitability of the spinal neurons is restored. Apparently, this is a common natural property of neurons throughout the nervous system, i.e. after the loss of a source of facilitating impulses, neurons increase their own natural degree of excitability in order to compensate for the loss at least partially. Hypertonicity is also supported by afferentation due to spontaneous activity of muscle receptors, and spontaneous activity of gamma motor neurons.
The spinal cord that has lost contact with the brain is defined as isolated, and the reflexes that can be carried out with its help are called spinal or spinal. Isolation of the spinal cord or part of it can occur as a result of a traumatic rupture in a person, and then the remaining reflex activity is reduced exclusively to spinal reflexes. Spinal reflexes are innate, their implementation does not require awareness, but in natural conditions, i.e. with preserved connections between the spinal cord and the brain, spinal reflexes are included in more complex behavior programs. The descending influences of the brain can change or even stop certain types of reflexes, the arc of which closes through the spinal cord, for example, a painful flexion reflex can be consciously suppressed by an effort of will.
The brain consists of the telencephalon (cerebral cortex, white matter, ba-
hall ganglia), intermediate, middle, posterior (bridge and cerebellum) and oblong
brain. Some of these structures are defined by the concept of the “brain stem” (medulla oblongata, pons and midbrain), the joint activity of which forms the main stem functions, for example, complex chain reflexes, regulation of muscle tone and posture, and the upward influence of the reticular formation on the telencephalon.
Medulla
The human medulla oblongata is about 25 mm long. It is a continuation of the spinal cord. Unlike the spinal cord, it does not have a metameric, repeatable structure; the gray matter in it is located not in the center, but with nuclei to the periphery.
AT medulla oblongata there are olives associated with the spinal cord, the extrapyramidal system and the cerebellum - this is a thin and wedge-shaped nucleus of proprioceptive sensitivity (the nuclei of Gaulle and Burdach). Here are the intersections of the descending pyramidal pathways and ascending pathways formed by thin and wedge-shaped bundles (Gaulle and Burdakh), the reticular formation.
Located in the medulla oblongata nuclei the following cranial nerves:
-vestibulocochlear nerve: vestibular nuclei innervating vestibular apparatus participates in the regulation of posture and balance, vestibulo-ocular and vestibulo-vegetative reflexes. The cochlear nuclei innervate the auditory receptors, participate in the auditory orienting reflex, and enter the conductive section of the auditory analyzer.
-glossopharyngeal nerve:consists of those parts. The motor part innervates the muscles of the pharynx and oral cavity, raises the pharynx and larynx, lowers the soft palate and epiglottis. The sensitive part receives taste, pain, tactile, temperature, pain, interoceptive sensitivity from the posterior third of the tongue and carotid body (vascular and cardiac reflexes). Participates in the act of chewing and swallowing, in secretory and motor digestive reflexes, in vascular and cardiac reflexes (from carotid body). The lower salivary part stimulates the secretion of the parotid gland.
- nuclei of the vagus nerve. It consists of three nuclei: the double (motor) nucleus is involved in the act of sneezing, swallowing, vomiting, coughing, and in the formation of the voice. The sensitive nucleus of the solitary pathway innervates the mucous membrane of the palate, the root of the tongue, and is involved in swallowing, chewing, respiratory, and visceral reflexes. The posterior parasympathetic nucleus innervates the muscles of the heart, smooth muscles and glands of the neck organs, is involved in cardiac, pulmonary, bronchial, digestive reflexes.
-accessory nerve, partially located in the medulla oblongata. .partially in the dorsal, innervating the sternocleidomastoid muscle, and the trapezius muscle, causes the head to tilt to the side, with the face turned in the opposite direction, raising the shoulder girdle up, bringing the shoulder blades to the spine.
Hypoglossal nerve: participates in the reflexes of chewing, swallowing, sucking in the implementation of speech.
conductor functions. All ascending and descending pathways of the spinal cord pass through the medulla oblongata: spinal-thalamic, corticospinal, rubrospinal. The vestibulospinal, olivospinal and reticulospinal tracts originate in it, providing tone and coordination of muscle reactions. In the medulla, the paths from the cerebral cortex end - the corticoreticular paths. Here ends the ascending pathways of proprioceptive sensitivity from the spinal cord: thin and wedge-shaped. Brain formations such as the pons, midbrain, cerebellum, thalamus, hypothalamus, and cerebral cortex have bilateral connections with the medulla oblongata. The presence of these connections indicates the participation of the medulla oblongata in the regulation of skeletal muscle tone, autonomic and higher integrative functions, and the analysis of sensory stimuli.
26.09.2012
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The nervous system controls the function of the body's cells. Reflex is the basis of this control. Simple reflexes close at the level of efferent neurons of the spinal cord.
Reflex is the response of the nervous system to a stimulus. At the heart of the reflex reflex arc.
Links of the reflex arc:
- source of irritation;
- afferent (sensitive) neuron;
- intermediate neuron;
- efferent (executive) neuron;
- body cells.
Combinations of links of the reflex arc can be different.
Reflexes are simple and complex. Simple reflexes close at the level of efferent neurons of the spinal cord (SM).
Simple reflexes that close at the level of the spinal cord include myotatic, tendon reflexes.
Myotatic reflex occurs when a muscle is stretched. When a muscle is stretched, it contracts. The reflex arc consists of two neurons: a muscle - an afferent neuron of the spinal ganglion - an α-motoneuron of the anterior horns of the gray matter of the SM - a muscle. The dendrite of the afferent neuron of the spinal ganglion forms branches in the muscle ending in receptors, the axon as part of the posterior root enters the posterior horns of the gray matter of the spinal cord, passes through them, forming a synaptic connection with the dendrite of the α-motoneuron of the anterior horns, responsible for the contraction of this muscle. The axon of the α-motor neuron leaves the spinal cord as part of the anterior root, leaves the spinal canal as part of the spinal nerve, goes to the controlled muscle, in which it forms numerous branches.
tendon reflex occurs when a tendon is stretched. When the muscle contracts, the tendon stretches, and when the tendon stretches, the muscle relaxes. The reflex arc consists of three neurons: muscle - afferent neuron of the spinal ganglion - afferent neuron of the posterior horns of the gray matter of the SM - α-motoneuron of the anterior horns of the gray matter of the SM - muscle. The dendrite of the afferent neuron of the spinal ganglion forms branches in the tendon ending in receptors (Golgi bodies), the axon, as part of the posterior root, enters the posterior horns of the gray matter of the spinal cord and forms a synaptic connection with the dendrite of the afferent neuron of the posterior horns of the gray matter of the spinal cord. The axon of the afferent neuron of the posterior horns of the gray matter of the SM forms a synaptic connection with the dendrite of the α-motoneuron of the anterior horns, which is responsible for the contraction of the muscle with which the tendon is associated. The axon of the α-motor neuron leaves the spinal cord as part of the anterior root, leaves the spinal canal as part of the spinal nerve, goes to the controlled muscle, in which it forms numerous branches. When the muscle contracts, the tendon is stretched - irritation of the Golgi bodies - the nerve impulse enters the afferent neuron of the posterior horns of the spinal cord - the nerve impulse from the afferent neuron of the posterior horns has an inhibitory effect on the α-motor neuron - the flow of impulses from the α-motor neuron to the muscle stops - the muscle relaxes.
Myotatic and tendon reflex act in combination. When a neurological hammer strikes the tendon, the muscle is stretched - the myotatic reflex is triggered - the muscle contracts. In response to muscle contraction (stretching of the tendon), a tendon reflex is triggered - following muscle contraction, it relaxes. Therefore, in neurological practice, the study of the myotatic and tendon reflexes are combined into one concept - the tendon reflex.
With central paralysis/paresis, tendon reflexes are enhanced ( hyperreflexia), with peripheral paresis - weaken ( hyporeflexia), with peripheral paralysis - disappear ( areflexia). Therefore, the study of tendon reflexes is of great diagnostic value, given that each tendon reflex closes in a certain segment of the spinal cord.
Biceps reflex closes in the CIV-CVI cervical segments of the CM. With a short blow to the tendon of the biceps of the shoulder (biceps), flexion occurs in the elbow joint.
Triceps reflex closes in the CVI-VII cervical segments of the CM. With a short blow to the tendon of the head muscle of the shoulder (triceps), extension occurs in the elbow joint.
Carpal-beam reflex closes in the CV-CVIII cervical segments of the CM. With a short blow in the region of the styloid process radius there is a flexion movement of the fingers of the hand, in the elbow joint.
knee jerk closes in the LII-LIV lumbar segments of the CM. With a short blow to the tendon below the patella, extension in the knee joint occurs.
Achilles reflex closes in the SI-SII sacral segments of the CM. With a short blow to the Achilles tendon, extension in ankle joint(plantar flexion of the foot).
In neurological practice, the definition is used to make a diagnosis. skin reflexes. The mechanism of skin reflexes is similar to the mechanism of tendon reflexes. Irritation of skin receptors causes muscle contraction.
Abdominal skin reflexes(upper, middle, lower) close in ThVIII-ThXII thoracic segments of the SM. Dashed movements on the skin of the abdomen below the costal arch, at the level of the navel, in the lower abdomen causes contraction of the abdominal muscles of the upper, middle, lower, respectively.
Cremaster skin reflex closes in the LI-LII lumbar segments of the SM. Dashed movements on the skin of the upper inner surface of the thigh causes contraction of the muscles of the testicle - the testicle is pulled up.
plantar skin reflex closes in the LV lumbar - SI sacral segments of the CM. Dashed movements on the skin of the plantar surface of the foot causes flexion of the toes.
anal skin reflex closes in the SIV-SV sacral segments of the CM. Dashed movements on the skin near the anus (near-anal region) causes a contraction of the external sphincter of the anus.
Superficial skin: abdominal – contraction of the muscles of the same half of the abdominal wall when irritated by its tip of the handle of the malleus below the edge of the costal arch (upper abdominal), at the level of the navel (middle abdominal) and above the inguinal fold (lower abdominal)
Ticket number 3)
1. Methodology for the study of pathological foot reflexes
Foot pathological reflexes are divided into flexion and extensor.
Flexion reflexes are characterized by slow flexion of the toes (similar to pathological carpal reflexes).
Symptom Rossolimo - the examiner with his fingertips delivers a short blow to the tips of the II-V toes of the subject's foot.
Zhukovsky's symptom caused by a blow of the hammer on the middle of the sole at the base of the fingers.
Symptom Bekhterev I caused by the impact of the malleus on the dorsum of the foot areas IV-V metatarsal bones.
Bechterew's symptom II caused by a blow of the hammer on the heel of the subject.
The extensor reflexes are characterized by the appearance of extension of the big toe; II-V fingers diverge fan-shaped.
Babinsky's symptom - the examiner passes the handle of the neurological malleus or the blunt end of the needle along the outer edge of the sole.
Oppenheim's sign the examiner draws the back surface of the middle phalanx of the II and III fingers along the anterior surface of the lower leg of the examined.
Gordon's symptom caused by compression of the calf muscle of the subject
Schaeffer's symptom caused by compression of the Achilles tendon.
Pussep's symptom caused by streaky irritation along the outer edge of the foot. In response, the little finger is abducted to the side.
Ticket number 4)
1.Methodology for the study of reflexes of oral automatism -
For bilateral lesions of the corticonuclear pathways, reflexes of oral automatism (pathological pseudobulbar reflexes) are examined.
Marinescu-Radovici palmar-chin reflex. With stroke stimulation of the palm, contractions of the chin muscles occur.
Wurp lip reflex. percussion on upper lip cause lip protrusion.
Oppenheim's sucking reflex. Stroke irritation of the lips causes a sucking movement.
Nasolabial reflex of Astvatsaturov. Percussion of the bridge of the nose causes protrusion of the lips with a "proboscis".
Corneomental and corneomandibular reflexes. Touching the cornea with cotton wool causes contraction of the muscles of the chin and movement of the lower jaw in the opposite direction.
Distance-oral reflexes characterized by contraction of the labial and mental muscles when approaching the face of an object.
The pharyngeal reflex in pseudobulbar paralysis is preserved, often elevated. As a rule, the mandibular reflex increases. Due to the disinhibition of the subcortical centers, phenomena of forced crying and forced laughter are observed.
Ticket number 5)
1.Methodology for the study of skin reflexes (Abdominal, plantar)
Ticket number 6)
1. method of studying the corneal reflex. Corneal irritation.
Corneal reflex (corneal reflex) - an unconditioned reflex of closing the palpebral fissure in response to irritation of the cornea of \u200b\u200bthe eye. The weakening or absence of the reflex may be associated with an organic lesion of the trigeminal or facial nerve, the brain stem, as well as with pathological processes in the cornea itself.
Corneal - With a piece of cotton wool rolled up in the form of a spindle, the doctor touches alternately the cornea of the right and left eyes. The response is the closing of the eyelids (m. Orbicularis oculi) Closes: on the side of irritation. r. ophthalmicus (I branch of the trigeminal nerve), sensory nucleus n. trigemini, motor nucleus n. facialis, m. orbicularis oculi Reflexes fade both with damage to the afferent and with damage to the efferent part of the arc. With the defeat of the V CN, there is no blinking on both sides, with the defeat of the VII pair - only on the side of the paralysis
Ticket number 7)
- sensitivity study technique.
To test pain sensitivity, use an ordinary needle or pin, touch the body with either a blunt or a sharp end of the needle. The injections should be short and not very frequent. During each touch, the patient must recognize the nature of the irritation and answer: "Acute" or "Stupidly." It is also necessary to pay attention to the reaction of the patient - mimic, vegetative.
Temperature sensitivity is examined using test tubes with hot (40-45 °C) and cold (5-10 °C) water. The patient must determine whether he was touched with a warm or cold test tube, and also say how vividly he feels temperature irritations in different parts of the skin.
Tactile sensitivity is examined using various means: a brush, a piece of cotton wool, paper. To exclude the summation of irritations, it is necessary to touch the skin abruptly. More subtle and accurate is the Frey technique using a set of bristles and hairs or using an extesiometer.
Ticket number 8)
1. Deep sensitivity research. Separately, muscular-articular, vibrational sensitivity, sensation of pressure and mass, skin kinesthesia are examined.
Muscular-articular sensitivity, or the sensation of passive movements, is checked by ascertaining the patient's ability to determine small passive movements in different directions and in different joints of the limbs (fingers, hands, feet, etc.). In a patient who lies with his eyes closed, first find out whether he recognizes the direction of light movements in the distal phalanges of the fingers. When the patient cannot determine the direction of light movements, they are made with a larger amplitude. In the case of disorders of sensation of movement in the fingers, the ability to determine the direction of movement in the proximal joints is examined.
Vibration sensitivity is checked with a tuning fork, the leg of which is placed on bone protrusions and the period during which the patient feels vibration is determined. Normally, a person feels a vibrating tuning fork C (256 vibrations per 1 minute) for 14-16 seconds. During the study of vibration sensitivity, attention is paid to a significant reduction in the duration or uneven perception of vibration in symmetrical areas.
Sensations of pressure and mass are examined using a set of weights of different masses placed on certain areas of the skin, for example, on the surface of the limbs or torso. A healthy person perceives changes by 10% of the initial mass.
Skin kinesthesia is examined by displacing a skin fold trapped in the fold. The patient is asked to determine the direction of movement.
Ticket number 9)
1. method of studying the functions of the facial nerve: the facial nerve of the 7th pair, the mixed nerve, (motor, prasympathetic, sensitive). The motor part provides innervation of all mimic mm of the face, mm of the auricle, skull, posterior belly of the digastric muscle, stapedius m, subcutaneous muscle of the neck. The central neurons are cells of the precentral cortex, the axons of which are part of the cortical-nuclear pathway to the bridge of the brain to the nucleus of the facial nerve of the opposite side. Peripheral motor neurons are represented by cells of the nucleus in the bottom of the 4th ventricle, axons of peripheral neurons form the root of the facial nerve, into the facial canal, 3 branches depart from it: Greater stony nerve, stapedial nerve, tympanic string. Research methodology: the state of innervation of mimic mm., asymmetry of the face, the severity of nasolabial folds, the eye blink test - in case of damage, the eyes blink asynchronously, the eyelid vibration test - the vibration of the eyelids is reduced or absent on the side of the lesion, the test of the study of the circular muscle of the mouth, the symptom of eyelashes.
Ticket number 10
1. Research methods of oculomotor nerves:
a) oculomotor nerves: carried out jointly, the condition and mobility of the eyeballs are checked, upper eyelids, size, shape, size and reaction of pupils to light.
b) external muscles of the eye: check their movement in all directions (the patient follows his eyes, without turning his head, behind the hammer moving in different directions); the patient is asked about the presence of diplopia and in which direction
in) pupillary reactions to light: straight (the patient is seated so that the eyes are illuminated with diffused light and the pupils are clearly visible and they are asked to look at the root of the nose of the examiner, who closes the patient's eyes with his palms; alternately opening one or another eye, check the reaction of the pupils to light; normally, the pupil narrows when illuminated and expands when dimmed) and friendly (one eye is closed with a palm and the examiner observes the other eye; when the eye is illuminated, the size of the pupil of the unlit eye changes), on accommodation and convergence (the patient looks at the tip of the index finger, which is either brought closer or removed; constriction of the pupils when considering nearby objects and their expansion when looking into the distance).
Ticket number 11)
1.method of research of the vagus and glossopharyngeal nerves:
The IX and X pairs of cranial nerves have separate common nuclei that are embedded in the medulla oblongata, therefore they are examined simultaneously. Determine the sonority of the voice, which may be weakened or completely absent (aphonia); at the same time, the purity of the pronunciation of sounds is checked. The patient is offered to pronounce the sound "a", say a few words, and then open his mouth. They examine the palate and tongue, determine whether there is a hanging of the soft palate, whether the tongue is symmetrically located. To determine the nature of the contraction of the soft palate, the subject is asked to pronounce the sound "e" with his mouth wide open. In case of damage to the vagus nerve, the palatine curtain lags behind on the side of the paralysis. Explore the palatine and pharyngeal reflexes with a spatula. It should be borne in mind that a bilateral decrease in the pharyngeal reflex and a reflex from the soft palate can also occur in the norm. Their decrease or absence on the one hand is an indicator of the defeat of IX and X pairs. Swallowing function is tested with a sip of water or tea. In the presence of dysphagia, the patient chokes on just one sip of water. Examine the taste on the back third of the tongue. With the defeat of the IX pair, the taste for bitter and salty in the posterior third of the tongue is lost, as well as the sensitivity of the mucous membrane of the upper part of the pharynx. To ascertain the status vocal cords laryngoscopy is performed.
Ticket number 12)
1 . accessory nerve research technique:
After examination and palpation of the muscles innervated by the accessory nerve, the patient is asked to turn his head first to one side and then to the other, raise his shoulders and arm above the horizontal level, and bring the shoulder blades together. To identify muscle paresis, the examiner resists these movements. For this purpose, the patient's head is held by the chin, and the examiner puts his hands on his shoulders. While lifting the shoulders, the examiner holds them with an effort.
Ticket number 13)
1.Methodology for studying the visual field (classical and rough).
Visual fields are evaluated separately for each eye. There are several methods for estimating them.
Sequential assessment of individual fields of vision. The doctor sits opposite the patient. The patient closes one of his eyes with his palm, and with the other eye looks at the nose of the doctor. We move the hammer or moving fingers along the perimeter from behind the head of the subject to the center of his field of vision and ask the patient to note the moment of seeing the hammer or fingers. The study is carried out alternately in all four quadrants of the visual fields.
Threat Method. It is used in those cases when it is necessary to examine the visual fields of a patient inaccessible to speech contact (aphasia, mutism, etc.). The doctor with a sharp "threatening" movement (from the periphery to the center) brings the unbent fingers of his hand closer to the patient's pupil, observing his blinking. In the case of a preserved field of vision, the patient blinks in response to the approach of a finger. All visual fields of each eye are examined.
The described methods are among the screening ones; more accurately, visual field defects are detected using a special device - the perimeter.
Ticket number 14)
1.Methodology for the study of the olfactory nerve.:
With calm breathing and closed eyes, the wing of the nose is pressed with a finger on one side and the odorous substance is gradually brought closer to the other nasal passage, which the subject must identify. Use laundry soap, rose water (or cologne), bitter almond water (or valerian drops), tea, coffee. The use of irritating substances (ammonia, vinegar) should be avoided, as this simultaneously causes irritation of the endings of the trigeminal nerve. It must be borne in mind whether the nasal passages are free or there are catarrhal discharges. Although the subject may not name the test substance, odor awareness precludes the absence of smell.
Ticket number 15)
1. Methodology for the study of the trigeminal nerve:
Find out from the patient whether he experiences pain or other sensations (numbness, crawling) in the face. On palpation of the exit points of the branches of the trigeminal nerve, their soreness is determined. Pain and tactile sensitivity are examined at symmetrical points of the face in the zone of innervation of all three branches, as well as in the zones of Zelder. To assess the functional state of the trigeminal nerve, the state of the conjunctival, root
al, superciliary and mandibular reflexes. Conjunctival and corneal reflexes are examined by lightly touching a strip of paper or a piece of cotton to the conjunctiva or cornea (Fig. 5.15). Normally, the eyelids close at the same time (the arc of the reflex closes through the V and VII nerves), although the conjunctival reflex may be absent in healthy people. The superciliary reflex is caused by a blow of the hammer on the bridge of the nose or the superciliary arch, while the eyelids close. The mandibular reflex is examined by tapping the chin with a hammer with the mouth slightly open: normally, the jaws close as a result of contraction of the masticatory muscles (the arc of the reflex includes sensory and motor fibers of the Vth nerve).
To study the motor function, it is determined whether the displacement of the lower jaw occurs when the mouth is opened. Then the examiner puts his palms on the temporal and chewing muscles in succession and asks the patient to clench and unclench his teeth several times, noting the degree of muscle tension on both sides.
Ticket number 16)
1.method of taste research: The main conductor of taste sensitivity from the anterior 2/3 of the tongue is the facial nerve, and from the posterior 1/3 of the tongue - the glossopharyngeal. The most widely used in the clinic is the drip method of taste research, which makes it possible to judge the state of taste sensitivity in different parts of the tongue by applying solutions with pipettes.
As the initial solutions of taste stimuli, solutions are taken that, in terms of concentration, correspond to the upper limits of taste in the norm. To study taste sensitivity in our patients, the following solutions were prepared: 1) sweet - 1; 5; 10% sugar; 2) salty - 1; b; ten; 20% table salt; 3) sour - 1; 2; 5; 10% hydrochloric acid; 4) bitter - 0.001; 0.01; 0.1% quinine hydrochloride.
These solutions, always in the same sequence, starting from threshold concentrations, were applied to the tongue with glass pipettes in the amount of 1-2 drops. The state of taste sensitivity was determined on the anterior 2/3 of the tongue and the posterior third of the tongue on the right and left.
Before the study and after each irritation, the oral cavity was rinsed with boiled water. Due to the peculiarities of the physiology of taste perception, irritations were applied at intervals of 2 to 5 minutes. The taste threshold for each of the stimuli was taken as the concentration of the solution correctly determined by the subject.
Loss of taste sensitivity - ageusia, decrease in it - hypogeusia, increase in taste sensitivity - hypergeusia, perversion of it - parageusia (with lesions of the facial and trigeminal).
Ticket number 17)
1. Methodology for the study of dynamic and static ataxia(Romberg pose)
Ataxia(from the Greek ataxia - disorder) - a disorder of coordination of movements; a very common dysmotility. Strength in the limbs is slightly reduced or completely preserved. Movements become inaccurate, awkward, their continuity and sequence are upset, balance is disturbed in a standing position and when walking. Static ataxia is a violation of balance in a standing position, dynamic ataxia is a violation of coordination during movement.
For determining static ataxia used Romberg's test: legs together, hands at the seams, head straight, eyes closed - stability is assessed. Stretch your arms in front of you at shoulder level, close your eyes. The pose becomes more complicated - the heel of one leg is brought to the toe of the other. Stability is assessed in Romberg's pose.
samples to the definition dynamic ataxia: hands in front of you, close your eyes, take out the tip of your nose with your index finger. A hit, a past hit, the presence of an inversion tremor are evaluated. Similarly index test: one and the other hand touch the tip of the hammer.
Ticket number 18)
1. Methodology for the study of tension symptoms: The symptom of Lasegue is characteristic of damage to the sciatic nerve: the leg extended at the knee joint is bent at the hip joint (the first phase of nerve tension is painful), then the lower leg is bent (the second phase is the disappearance of pain due to the cessation of nerve tension). Matskevich's symptom is characteristic of the defeat of the femoral nerve: the maximum flexion of the lower leg in a patient lying on his stomach causes pain on the anterior surface of the thigh. If the same nerve is affected, the Wassermann symptom is determined if the patient lying on his stomach is unbent at the hip joint, then pain occurs on the anterior surface of the thigh, damage to the peripheral nerves causes a neural type of sensitivity disorder - pain, hypesthesia or anesthesia, the presence of pain points in the area of innervation , tension symptoms.). Plexalgic type (with damage to the plexus) - pain, symptoms of tension of the nerves coming from the plexus, impaired sensitivity in the zone of innervation. Usually, there are also movement disorders. Radicular type (with damage to the posterior roots) - paresthesia, pain, disturbances of all types of sensitivity in the corresponding dermatomes, symptoms of root tension, pain in the paravertebral points and in the spinous processes
Ticket number 19)
1. Methodology for the study of muscle tone: assessed during examination and palpation mm, with a decrease in m tone m flabby soft pasty, with increased tone has a dense consistency, through the implementation of passive movements (hypotension and atony, Orshansky's symptom - when the limb is extended to the top at the knee joint, overextension is detected in it due to hypotension, with paralysis and paresis, damage to the nerve, root, anterior horn of the spinal cord, cerebellum, trunk, striatum and posterior cords; Muscle hypertension, tension felt during passive movements: spastic - flexors pronators of the arm and extensor adductors of the leg (pyramidal path) the tone does not change or decreases, with plastic muscle tone increases - the sensation of tremors during passive movements (pallido- nigral system).
Ticket number 20)
1. Methodology for the study of the symptoms of Bare, Bare-Rusetsky: bare: lying on the stomach, legs bent at the knee joint - the paretic leg goes down; B-R: with arms outstretched forward, with eyes closed- one hand goes down.
Ticket number 21)
1. methodology for the study of meningeal symptoms:
Meningeal:
1. The rigidity of the neck muscles is caused by an increase in the tone of the neck extensor muscles. Resistance is felt when trying to bend the head to the chest.
2. Kernig's sign
3. upper Brudzinski's symptom
4. Brudzinski's mean symptom
5. lower Brudzinski's symptom
12. Le Sage's sign of suspension
14. pointing dog pose
Ticket number 22)
- methods for studying the two-dimensional-spatial sense of stereognosy
Stereognostic, or three-dimensional-spatial, sense is the ability to recognize familiar objects by touch with eyes closed. Violation of stereognosis subject to complete preservation general types sensitivity is called astereognosis.
The two-dimensional-spatial feeling is examined by offering the patient, closing his eyes, to determine the numbers, letters, figures “drawn” on his skin.
Ticket number 23)
1.method of research of the hypoglossal nerve: The patient is offered to stick out his tongue and at the same time they monitor if he deviates to the side, note if there is atrophy, fibrillar twitching, tremor. At the nucleus of the XII pair there are cells from which fibers come that innervate the circular muscle of the mouth, therefore, with a nuclear lesion of the XII pair, thinning, wrinkling of the lips occur; the patient cannot whistle.
Ticket number 24)
1.methodology for the study of praxism. Types of praxism. Praxis - the ability to perform sequential sets of movements and perform targeted actions according to a developed plan. Actions in progress vocational training. Recognition of objects performance of successive acts.
Apraxia- loss of skills. Occurs when the parietal-temporal-occipital region of the dominant hemisphere is damaged (both halves of the body suffer). With the defeat of the subdominant hemisphere and the corpus callosum - one side (for right-handed people - the left). motor apraxia- the patient understands the task, but cannot complete it, does not repeat the movements. ideational apraxia- does not perform actions with real objects, imitation is preserved. Automatic actions. Constructive Apraxia- performs actions on imitation or verbal order, but does not create a qualitatively new motor act, does not add up the whole from parts. For research, a number of tasks are offered (sit down, wag a finger, comb your hair), tasks with imaginary objects (how they eat, how they call on the phone), evaluate imitation, construction. For the study of gnosis and praxis - psychological methods: Segen boards with indentations different shapes, where you want to nest shapes of a certain shape. Koss technique: cubes different colors, of which it is necessary to add a pattern according to the picture. Link's cube: you need to add a cube from 27 cubes of different colors so that all its sides are the same color.
Ticket number 25
- gnosia recognition of objects
Agnosia - loss of the ability to recognize in the absence of disturbed feelings, vision, hearing, smell, taste.
Types: visual, hearing, tactile, pain, smell, taste. Visual - the patient sees the object but cannot recognize it obs when it is damaged outward on top of the back of the lobes. Md research: the patient is asked to show or take certain objects.
Auditory - the patient does not understand the origin and meaning of sounds, cannot recognize an object by sound. Observation at the defeat of the lion temporal lobe. Md research: bring a watch to your ear, pour water.
Tactile (sensitive) - while maintaining the senses, he cannot recognize the object by feeling (astereognosis). Observable when the lion is struck by the temporal lobe. Md research: you need to recognize the object by touch with your eyes closed.
Ticket number 26)
1. Aphasia - the center of the violation has already formed speech, with a cat. the ability to use words to express thoughts or communicate is partially or completely violated while maintaining the function of articulation. apparatus and hearing.
Types: sensory, motor, amnestic, semantic, total.
Sensory (impressive) - with the defeat of the center of Wernicke (posterior section of the top of the temporal gyrus, the house of the hemispheres). Lack of understanding of the speech of others while maintaining the ability to speak. But the speech is wrong with paraphasias, it represents a set of meaningless words. Paraphasias: literal - replacement / rearrangement of letters in a word, verbal - replacement of some words by others.
Motor - with a lesion of Broca's speech center (back sections of the lower forehead from the outside of the hemispheres) - a violation of the utterance of the active oral speech. Speech comprehension is preserved. Combined with agraphia (loss of the ability to write).
Amnestic - in case of damage to the lower and rear sections of the topics and the upper region. The patient speaks well and understands other people's speech, but cannot correctly name objects, "forgets" words, knows and can describe the purpose of the object, names the object when prompted.
Semantic - the defeat of the lion by the high-rise region in right-handed people. The understanding of the meaning of sentences with a complex structure is impaired.
Total - defeat from Broca's area to Wernicke's area - violation of sensory and motor cortical areas of speech - Complete loss of the ability to speak and understand addressed speech.
Ticket number 27)
1.Normal cerebrospinal fluid consists of 90% water and 10% organic and inorganic substances, transparent, colorless, has a slightly alkaline reaction (pH 7.35-7.4), density 1003-1008, pressure: 60 drops per minute (normal during puncture cerebrospinal fluid is excreted in drops), contains protein in the amount of 0.2-0.3 g / l (mainly albumin, with no or a small amount of globulin), contains cells in the amount of 3-4 in 1 μl (lymphocytes, cells of the meninges) , contains glucose in the amount of 2.22 - 3.33 mmol / l, chlorides - 125 mmol / l, potassium - 2.9 mmol / l, sodium - 149.9-156.6 mmol / l, calcium-1.7 mmol/l, magnesium-0.8 mmol/l, phosphorus-0.6 mmol/l.
Ticket number 28)
1. Methodology for the study of local and reflex dermographism.
after dashed skin irritation, a local vasomotor reaction appears, determines vascular tone and regulatory mechanisms. Local - with a blunt non-scratching object, after 5-20 seconds a white strip appeared, disappearing after 1-10 minutes (white dermographism), if you hold harder and more slowly, a red strip appears (red dermographism) disappearing up to 1 hour (+ may towering dermographism). Reflex - by applying a strong but not damaging irritation with the tip of a pin, after 5-30 seconds on both sides of the strip of pink and red spots with a hold of up to 1-10 minutes,
Ticket number 29)
1.methods of examination of the auditory nerve:
By questioning, they find out if the patient has a hearing loss or an increase in the perception of ringing sounds, tinnitus, auditory hallucinations. After that, the hearing acuity is determined for each ear separately. To do this, the patient closes the ear canal with his finger, turns to the other ear conducting the study and repeats after him the words spoken in a whisper. The examiner should be at a distance of 6 m. Normally, whispered speech is perceived at a distance of 6-12 m. (organ of Corti, cochlear part of the VIII nerve and its nucleus) apparatus. Tuning forks (Rinne and Weber technique) or audiometry are used to distinguish middle ear lesions from lesions of the cochlear part of the VIII nerve.
Ticket number 30)
1. Meningeal syndrome: symptoms of meningeal syndrome:
It consists of cerebral and actually meningeal symptoms.
A) General cerebral:
1. intense diffuse headache
2. sudden, intense ("fountain"), unrelieved vomiting without nausea
3. general hyperesthesia (tactile, visual, sound)
4. non-systemic dizziness
5. impaired consciousness of varying degrees, delirium, hallucinations
6. generalized or focal epileptic manifestations are possible
B) Meningeal:
1. neck muscle stiffness
2. Kernig's sign: impossibility of extension at the knee joint of the leg, previously bent at the hip and knee joints
3. upper Brudzinski's symptom: when the head is passively brought to the chest in a supine position, the legs are bent at the knee and hip joints
4. Brudzinski's mean symptom: when pressing on the area of the pubic joint, bending of the legs in the knee and hip joints is observed
5. lower Brudzinski's symptom: when checking for Kernig's sign, involuntary flexion of the other leg in the same joints occurs
6. increased headache when bending the head to the chest
7. Lobzin's symptom: the appearance of pain when pressing on the anterior wall of the external auditory canal from the inside
8. Kehrer's symptom: the appearance of pain with pressure at the exit point of the occipital nerve
9. Flatau's symptom: dilated pupils when the head is tilted forward
10. Bechterew's symptom: percussion on the zygomatic arch increases the headache and causes contraction of facial muscles
11. Pulatov's symptom (craniofascial reflex): painful grimace during percussion of the skull
12. Le Sage's sign of suspension: if a child with meningitis is lifted by the armpits, then pulls the legs to the stomach and holds them in this position
13. tension and protrusion of the large fontanel on palpation, the sound of a "cracked pot" on percussion in infants
14. pointing dog pose: head thrown back, legs pulled up to the stomach
Ticket number 31)
1. direct and friendly reaction of the pupils to light (the reaction is lively, friendly - when one is closed, the other is open, and when the opening is a friendly constriction), convergence is checked by approaching the hammer from 50 cm to 3 cm from the nose in the middle - convergence of the eyeballs and holding them at the point fixation (5 cm), change in the size of the pupils as the eyeballs approach each other, normally the narrowing reaches a sufficient 15 cm; accommodation - normally, when looking into the distance, the pupil expands, when transferred to nearby, it narrows;
2. syndrome of damage to the posterior horns of the spinal cord (posterior horn syndrome) - manifested by a dissociated violation of sensitivity (decrease in pain and temperature sensitivity while maintaining articular-muscular tactile and vibration) on the side of the focus, segmental type of disorders, extinction of deep reflexes.
Ticket number 32)
- Methodology for the study of pathological reflexes.
Pathological reflexes are perverted reflexes that are not normally observed, appearing only when the central motor neuron is damaged. Normally, pathological reflexes are caused in children under the age of one and a half years.
Pathological reflexes include:
1. Foot pathological reflexes of the extensor group;
2. Carpal and foot reflexes of the flexion group;
3. Clonuses;
4. Protective reflexes;
5. Adductor reflexes;
6. Synkinesis;
7. Reflexes of oral automatism;
8. Grasping reflex.
Ticket number 33)
1.technique of lumbar puncture
Lumbar puncture is performed with the patient lying down or sitting. The patient is laid on his side, the legs are bent at the knee joints, the hips are maximally brought to the stomach, the head is bent forward. The puncture is performed with a needle with a mandrel (a rapid outflow of fluid through a hollow needle can lead to a sharp drop in cerebrospinal fluid pressure). The needle is inserted into the gap between the spinous processes of the II-III or III-IV lumbar vertebrae. The reference point for insertion is the point of intersection of the line connecting the iliac crests and the spine.
The needle is inserted strictly in the sagittal plane. In older children and adults, the spinous processes are lowered down, so the needle is inserted at an acute angle. The introduction is made slowly, unsharply. At the moment of puncture of the dura mater, a “failure” of the needle into the subarachnoid space is felt.
In the final tank "float" the roots of the spinal nerves (cauda equina). With the slow introduction of the needle, the roots move away. With rapid introduction, infringement of the roots may occur and the patient complains of pain in the legs. In this case, you need to slightly pull the needle towards you. If the needle hits the bone, then it should be removed and re-introduced.
A) Reflex from tendon m. bicipitis. A blow with a percussion hammer on the tendon of the biceps muscle of the shoulder causes flexion of the arm in the elbow joint. Reflex evoking technique. The researcher stands in front of the researcher, with his left hand takes the patient's hand, bent at the elbow joint at an obtuse angle, and with his right hand strikes the lacertus fibrosus m with a hammer. bicipitis. This reflex is associated with the musculocutaneous nerve. The spinal center of the reflex is located in the C5-C6 segments.
b) Reflex from tendon m. tricipitis. A blow with a hammer to the tendon of the triceps muscle of the shoulder causes extension of the arm in the elbow joint. Reflex evoking technique. The examiner stands to the side of the examinee. He slightly takes the patient's arm outward and backward, bends it at the elbow joint almost at a right angle and, supporting it in the area elbow joint with the brush of his left hand, with his right hand he strikes with a hammer on the tendon of the triceps muscle. The reflex is associated with the radial nerve. The spinal center of the reflex is located in the C7-C8 segments.
c) Patellar (or patellar) reflex. A blow with a percussion hammer on the patellar ligament causes extension of the leg in the knee joint. Reflex evoking technique. The patient sits on a chair in a comfortable position, his legs are slightly bent at the knee joints and rest on the floor with one heel, the socks are raised. The examiner places his left hand on the patient's thigh, and with his right hand strikes his own ligament of the patella with a hammer. This causes contraction of the quadriceps femoris, which is accompanied by extension of the lower leg. You can use another technique: the patient sits on a chair, throwing one leg over the other: the reflex is examined on the thrown leg.
It is more convenient to examine knee reflexes when the patient is lying down. The subject lies on his back, his legs are bent at the hip and knee joints and rest his heels on the bed. The examiner brings his left hand under the legs of the subject (in the area of the knee joints), and with his right hand strikes with a hammer on the patella ligament of one or the other leg. Finally, it is possible to examine the track reflexes in a patient sitting on a bed or on a high stool with dangling legs. Each of these approaches has its own merits. It is often necessary to examine reflexes in the same patient using different ways to obtain completely objective data. The innervation of the patellar reflex is associated with the femoral nerve. The spinal center of the reflex is located in the L2-L4 segments.
When examining the knee-jerk reflex, it is necessary to turn Special attention on the complete relaxation of the muscles of the leg, since insufficiently relaxed muscles can simulate a decrease or even absence of a reflex. To relax the muscles, it is necessary to distract the attention of the subject from his leg, for which he is offered to solve easy arithmetic problems or count through one, clench and unclench his fists, answer questions asked of him, etc. To divert the attention of the subject, they often use the Jendrassik technique: the patient folds his hands in such a way that the hands are facing each other with palmar surfaces, and the fingers (II-IV) of one hand bent at the interphalangeal joints lie on the fingers of the other bent in the same way. The patient is offered to stretch the hands clasped in this way outward. It should be noted, however, that the Jendrassik technique and similar techniques do not always facilitate the evoking of the reflex. Some people, by stretching their arms, cause such tension of the entire muscles of the body that it becomes completely impossible to get a knee jerk. Therefore, it is necessary to resort to other methods of distraction.
d) Achilles reflex. A blow to the Achilles tendon causes plantar flexion of the foot. Reflex evoking technique. The reflex from the Achilles tendon is evoked in the position of the patient on his knees. The patient is on his knees, on a chair, on which a soft bedding is placed. The examiner takes the patient's foot by the toe with the left hand and produces a dorsal flexion to cause a slight passive tension of the Achilles tendon. With his right hand, he hits the Achilles tendon with a hammer, stepping back two centimeters from the calcaneus. The spinal center of the reflex is located in the L5-S2 segments. In the supine position of the patient, the Achilles reflex is examined as follows. The patient lies on his back. The examiner bends the patient's leg at the knee joint and throws it over the lower leg of the other leg. Then the examiner, slightly bending the foot of the examined leg to the rear with his left hand, strikes the Achilles tendon with a hammer with his right hand.
e) Mandibular (or mandibular) reflex. A wooden, metal or rubber stick (spatula, spoon handle) is placed on the teeth of the lower jaw of the subject with a slightly open mouth, the other end of which is held by the examiner with his left hand. On this stick, on its site between the teeth of the researcher and the researcher's left hand, the latter strikes with a percussion hammer. The result of such a blow is the contraction of the masticatory muscles and the movement of the lower jaw upward. The mandibular reflex is referred to as a tendon reflex. It is connected with the sensory and motor root of the trigeminal nerve. The mandibular reflex disappears with the destruction of the structures that carry it out, the defeat of the pyramidal bundle above this level causes an increase in the reflex. Bilateral damage to the pyramidal tract causes a particularly significant increase in the reflex.
e) Shoulder-scapular reflex. A blow with a hammer on the shoulder blade, somewhat outward from the middle of its inner edge, causes, with the arm lowered freely down, bringing the shoulder to the body and rotating it outward. This tendon reflex is characterized by considerable constancy. Of clinical importance is mainly the unilateral absence of the reflex (with C4 lesions).