Reflex. Definition. Types of reflexes. Conditioned and unconditioned reflexes What is a reflex briefly and clearly

Reflex I Reflex (lat. reflexus turned back, reflected)

reaction of the body that ensures the emergence, change or termination of the functional activity of organs, tissues or the whole organism, carried out with the participation of the central nervous system in response to the body's receptors.

The structural basis of reflex activity is. It consists of receptors (they perceive irritation and are part of an afferent neuron), afferent, or sensory, nerve fibers (transmit receptor impulses to the nervous system), a nerve center (the synthesis of afferent excitation also occurs in it), efferent, or motor, nerve fibers ( transmit from the nerve center to the executive apparatus), effectors or executive organs (, vessels, glands, etc.). The areas of a body including set of receptors which irritation causes certain R., are called reflexogenic zones. These zones are found in all organs and tissues of the body. For example, irritation of the surface of the cornea of the eye causes R. blinking, the mucous membrane of the nasopharynx - R. sneezing. Examples of such zones of internal organs are aortic-carotid, including the aortic arches, and located at the branching point of the common carotid artery into external and internal. It consists of two formations - the carotid sinus and the carotid glomerulus, in which chemoreceptors are also located; of this zone are involved in the regulation of the level and activity of the respiratory center.

The reflex is the basic unit of nervous action. Under natural conditions, R. are not carried out in isolation, but are combined (integrated) into complex reflex acts that have a certain biological orientation. The biological significance of reflex mechanisms lies in the regulation of the work of organs and the coordination of their functional interaction in order to ensure the constancy of the internal environment of the body (see Neurohumoral regulation of functions, homeostasis), maintaining its integrity and the ability to adapt to constantly changing environmental conditions (see Higher nervous activity, Instinct, functional systems).

Reflexes are combined into different groups depending on the leading feature taken as the basis for their division. According to I.I. Pavlov, all reflexes are divided into congenital, or unconditioned (they are specific and relatively constant), and individually acquired, or conditional, R. (they are changeable and temporary and are developed in the process of interaction of the organism with the environment). The characteristic of R. on separate links of a reflex arch is quite widespread. According to the localization of receptors, R. are divided into extero-, intero-, and proprioceptive; according to the location of the central link, they are divided into spinal, bulbar, mesencephalic, cerebellar, diencephalic, and cortical; according to the localization of the efferent part - into somatic and vegetative; according to the evoked reaction - to swallowing, blinking, coughing, etc. In neurological practice most often use the scheme of R.'s division into superficial and deep. Superficial reflexes include R. from the mucous membranes and skin, while deep reflexes include tendon, subcutaneous, and articular reflexes. There are also so-called motor-visceral R., in which muscle contractions through the proprioceptive afferent system cause a change in one or another vegetative reaction, for example, the Dagnini-Ashnez oculomotor reflex, or the oculomotor R., caused by pressure on the subject, normally leads to a slowdown in the pulse at 8-10 bpm.

The degree of R.'s "maturity" and the stability of their manifestation depend on the person's age. In the early postnatal period, there is a rapid R. ready at birth, as well as the formation of new ones. Further coordination of the emerging R. and their sets is carried out due to the maturation of synaptic structures (see Synapse) and the mechanisms of central inhibition (Inhibition). As the body ages, irreversible structural changes occur in nerve cells, which are accompanied by a decrease in excitability, a decrease in the rate of excitation conduction; at the same time, inhibitory processes are weakened, the time for performing reflex acts increases.

The nature and intensity of the reflex reaction upon stimulation of the same reflex zone depend on the functional state of the organism and the intensity of the irritation. In clinical practice, a significant number of R., having a similar structure of the reflex arc, is being investigated. For each of them, a special research methodology has been developed (see Reflexes in neuropathology).

For R.'s analysis in health and disease (reflexometry), a set of techniques is used using specialized devices - reflexometers. has found wide application in various fields such as athletes, biomedical and psychological research, as well as in detailed clinical research and the diagnosis of occupational diseases.

Bibliography: Bekhtereva N.P. Healthy and large human brain, L., 1980; General nervous system, ed. P.G. Kostyuk, L., 1979; Pavlov I.P. Twenty years of experience in the objective study of the higher nervous activity (behavior) of animals. , M., 1973; Simonov N.V. person. Motivational-emotional aspects, M., 1975; Sherrington C.S. Integrative activity of the nervous system, . from English., L., 1969, bibliogr.

II Reflex(s) (reflexus; Latin “reflection”, from reflecto, reflexurn to turn, turn back)

the reaction of the body to irritation, carried out with the participation of the nervous system.

Reflex adductor(r. adductorius) - physiological periosteal P.: hips when tapping along the iliac crest, pubic symphysis, the inner surface of the knee or along the tibia.

Reflex adductor dorsal(r. adductorius dorsalis; .: McCarthy spinoadductor reflex, adductor reflex, Chlenova - McCarthy reflex) - P .: adduction of one or both hips of a sitting with legs apart examined when tapping on the spinous processes of the vertebrae; observed with damage to the pyramidal tract.

Reflexes allied(French allier to connect, connect) - P., mutually reinforcing each other.

Reflex anal(r. analis) - physiological P.: external sphincter of the anus with tingling or dashed irritation of the skin around it; called in the position of the subject on the side with the legs brought to the stomach.

Reflexes antagonistic(r. antagonistici) - P., one of which has an inhibitory effect on the other.

Auropalpebral reflex(r. auropalpebralis; lat. auris + palpebra eyelid; syn. R. cochleopalpebral) - physiological P.: closing of the eyelids upon sudden exposure to a sound stimulus.

Reflex auropupillary(r. auropupillaris; lat. auris ear + pupilla) - physiological P.: rapid constriction of the pupils, followed by their slow expansion upon sudden exposure to a sound stimulus.

Achilles reflex(r. Achillis) - physiological P.: plantar foot when struck with a hammer on the calcaneal (Achilles) tendon.

Ashner's reflex- see Oculocardial reflex.

Babkin's reflex- see Palmar-roto-head reflex.

Reflex unconditioned(syn. R. congenital) - congenital P., constantly arising in individuals of a given species and age with adequate stimulation of certain receptors.

Reflex abdominal(r. abdominalis) - the common name for physiological P., manifested by the contraction of any muscles of the anterior abdominal wall.

Upper abdominal reflex(r. abdominalis superior) - superficial R. b., in which irritation is applied along the costal arch.

Deep abdominal reflex(r. abdominalis profundus) - R. b., caused by a blow of the hammer on the iliac crest, on the pubis or on the costal arch.

Abdominal cutaneous reflex(r. abdominalis cutaneus) - see Abdominal superficial reflex.

Reflex abdominal lower(r. abdominalis inferior) - superficial R. b., in which irritation is applied to the inguinal ligament.

Reflex abdominal superficial(r. abdominalis superficialis; synonym R. abdominal skin) - R. b., caused by rapid dashed irritation of the skin of the abdomen in the direction from the periphery to the midline.

Medium abdominal reflex(r. abdominalis medius) - superficial R. b., in which irritation is applied to the skin of the abdominal wall at the level of the navel.

Bulbar reflexes(r. bulbares) - P., the reflex arc of which closes in the nuclei of the medulla oblongata (for example, pharyngeal, palatine, swallowing, sucking P.).

Bulbocavernous reflex(r. bulbocavernosus) - physiological R.: contraction of the bulbous-spongy muscle with slight squeezing of the glans penis with fingers.

Reflex vegetative(r. vegetativus) - the common name for P., which regulate the activity of glands, blood vessels, internal organs, smooth muscles, and also have various adaptive and trophic effects.

Reflex vegetosomatic(r. vegetosomaticus) - see Visceromotor reflex.

Vestibulospinal reflex(r. vestibulospinalis; syn.) - physiological P.: deviation of the torso and limbs to the side with irritation of the receptors of the vestibular analyzer.

Reflex vestibular tonic(r. vestibulotonicus) - R.: change in muscle tone on the side of irritation of the labyrinth receptors.

Reflex visceral(r. visceralis; syn.) - the common name of P., caused by irritation of the internal organs or manifested by a change in the function of any internal organs.

Reflex viscerovasomotor(r. viscerovasomotorius) - P.: change in the lumen of blood vessels when receptors of internal organs are irritated.

Reflex viscero-visceral(r. viscerovisceralis) - visceral P.: a change in the activity of an internal organ when receptors of another internal organ are irritated.

Reflex viscerodermal(r. viscerodermalis) - see Reflex viscerocutaneous.

Reflex viscerocutaneous(r. viscerocutaneus; synonym R. viscerodermal) - visceral R.: a change in the sensitivity of certain areas of the skin (Zakharyin-Ged zones) upon irritation of the receptors of the internal organ.

Reflex visceromotor(r. visceromotorius; synonym: R. vegetosomatic, R. viscerosomatic) - visceral P.: contraction of certain skeletal muscles during irritation of the receptors of the internal organ.

Reflex viscerosecretory(r. viscerosecretorius) - visceral P.: a change in the activity of certain glands of external or internal secretion when the receptors of the internal organ are irritated.

Reflex viscerosensory(r. viscerosensorius) - visceral P.: the occurrence of various sensations when stimulating the receptors of internal organs.

Reflex viscerosomatic(r. viscerosomaticus) - see Visceromotor reflex.

Reflex taste-lacy(r. gustolacrimalis) - unilateral profuse with irritation of taste buds; occurs on the side of the lesion of the facial nerve (in the region of the ganglion of the knee).

Reflex cardiovascular(r. cardiovascularis) - vegetative R.: a change in the lumen of the blood vessels when the receptors of a certain part of the heart are irritated.

Reflex cardio-cardiac(r. cardiocardialis) - vegetative P: a change in the activity of the heart or its departments with a change in pressure in the cavities of the heart (for example, a drop in pressure in the left ventricle causes reflex acceleration and increased contractions).

Reflex carpoulnar(r. carpoulnaris; Greek karpos wrist + anat. ulna ulna) - see Reflex.

Cough reflex(r. tussis) - physiological P.: arising from irritation of the respiratory tract receptors.

Reflex clinostatic(r. clinostaticus; Greek klinō tilt + statikos occupying a certain position) - somatovegetative R.: decrease in heart rate by 6-8 beats per 1 minute. when moving from a vertical to a horizontal position.

Reflex skin-visceral(r. cutaneovisceralis) - visceral P., which occurs when skin receptors are irritated.

Reflex skin-muscle(r. cutaneomuscularis) - a change in muscle tone or their contraction when skin receptors are irritated.

Reflex skin-cardiac(r. cutaneocardiacus) - skin-visceral P., manifested by a change in any parameters of cardiac activity (rhythm, stroke volume, etc.).

Reflex mucocutaneous(r. cutaneomucosus) - skin-visceral P., manifested by a change in the secretory and (or) absorption activity of the mucous membranes.

Skin reflex(r. cutaneus) - the common name for P., caused by irritation of skin receptors.

Reflex knee(r. genualis; synonym:, R. patellar, R. with the quadriceps femoris,) - physiological P.: extension of the lower leg when the hammer strikes the tendon of the quadriceps femoris under the patella.

Reflex knee pendulum(syn.: Rusetsky rocking knee reflex,) - rhythmic, gradually decreasing but in amplitude oscillatory movements of the lower leg when evoking knee P.; observed in cerebellar hypotension.

Reflex conjunctival(r. conjunctivalis) - physiological P.: closing of the eyelids with a light touch on the conjunctiva of the eyeball.

Reflex coordinated(r. coordinatus) - P., in the implementation of which various muscles, sometimes remote from each other, participate (for example, cough P., vomiting P.).

Reflex corneal(r. cornealis) - see Reflex corneal.

Reflex corneomandibular(r. corneomandibularis; anat. cornea + mandibula lower jaw; synonym: Zelder corneomandibular) blinking-chewing test, R. corneopterygoid) - pathological R.: friendly contraction of the circular muscle of the eye and the external pterygoid muscle, followed by movement of the lower in the opposite direction when touching the cornea or vigorously closing the eye; a sign of bilateral damage to the cortical-nuclear pathways.

Reflex corneopterygoid(anat. cornea cornea + pterygoideus pterygoid) - see Corneomandibular reflex.

1) physiological P.: turning the eyes towards the sound source; 2.) physiological R.: change in heart rate and respiration with intense sound stimulation.

Reflex cochleopalpebral(r. cochleopalpebralis; anat. cochlea snail + palpebra eyelid) - see Auropalpebral reflex.

Reflex cochleopupillary(r. cochleopupillaris; anat. cochlea cochlea + pupula pupil) - see Cochlear reflex.

Reflex cochleostapedial(anat. cochlea cochlea + musculus stapedius stapedius muscle) - physiological P.: contraction of the stapedial muscle with intense sound stimulation, manifested by a sensation of pain in the ear.

Reflex cremasteric(anat. musculus cremaster muscle that lifts the testicle; synonym cremaster reflex) - physiological P.: tightening of the testicle with dashed skin irritation of the upper inner surface.

Reflex cubital(r. cubitalis; anat. cubitalis ulnar) - see Ulnar reflex.

Cubito-pronator reflex(r. cubitopronatorius; anat. cubitus + musciilus pronator pronator) - see Ulnar reflex.

Reflex Kussmaul - Genzler- see Reflex search.

Reflex labyrinth(r. labyrinthicus) is the common name for tonic P., caused by irritation of the receptors of the vestibular apparatus.

Reflex palmo-roto-head(r. palmoorocephalicus; syn.) - physiological R. in children under the age of 3 months: opening the mouth sometimes with the head tilted forward with pressure on the palmar surface of the hand at the base of the thumb.

Reflex scapular(r. scapularis; syn. Steinhausbn scapuloperiosteal reflex) - physiological R. adduction of the scapula when tapping along its inner edge or with dashed skin irritation medially from the inner edge of the scapula.

Reflex scapular-brachial(r. scapulobrachialis; syn. Bekhterev's scapular-shoulder reflex) - physiological P.: bringing the shoulder and rotating it outward when hitting the inner edge of the scapula with a hammer.

Radiation reflex(r. radialis; synonym: R. head of the beam, R. carporadial, R. metacarpal-radial, R. radiopronator, R. styloradial) - physiological P .: and flexion of the forearm, sometimes fingers when the hammer strikes the styloid process of the radius bones.

Reflex mamilloareolar(r. mamilloareolaris; lat. mamula nipple + areola mammae) - physiological P.: contraction of the smooth muscle fibers of the peripapillary circle, manifested by its noticeable thickening when the surface of the nipple is irritated.

Reflex mandibular(r. mandibularis; syn. masseter-reflex) - physiological P.: contraction of the masticatory muscles when struck with a hammer directly on the chin or on a spatula placed on the lower ones with a half-open mouth.

Reflex medioplantar(r. medioplantaris; lat. medium middle + planta sole) - physiological P.: flexion of the foot when struck with a mallet in the middle of the sole.

Reflex blinking- protective P: contraction of the circular muscle of the eye, for example, with a sudden illumination of the eye or the appearance of an object in front of the eyes.

Reflex myostatic(nrk) - see Stretch reflex.

Reflex monosynaptic(r. monosynapticus; Greek monos one + Synapse) - P., the reflex arc of which does not include intercalary neurons.

Reflex motor-vascular(r. motovascularis) - somatovegetative P.: change in the lumen of blood vessels with irritation or contraction of skeletal muscles.

Reflex motor-visceral(r. motovisceralis) is the common name for somatovisceral R. in the form of a change in the activity of any internal organs during irritation or contraction of the skeletal muscles.

Motor-dermal reflex(r. motodermalis) - somatovegetative P.: change in skin functions, such as sweating with irritation or contraction of skeletal muscles.

Motor-gastric reflex(r. motogastricus) - motor-visceral P.; a change in the secretory and motor activity of the stomach with irritation or contraction of the skeletal muscles.

Motor-cardiac reflex(r. motocardiacus) - motor-visceral P.: change in the rhythm of heart contractions with irritation or contraction of skeletal muscles.

Reflex motor-renal(r. motorenalis) - motor-visceral P.: change in kidney function during irritation or contraction of skeletal muscles.

Reflex motor-respiratory(r. motorespiratorius) - motor-visceral R.: change in the frequency and depth of breathing with irritation or contraction of skeletal muscles.

Superciliary reflex(r. superciliaris; synonym McCarthy supraorbital reflex) - physiological P.: closing of the eyelids when tapping along the inner edge of the superciliary arch.

Supraorbital reflex McCarthy- see Brow reflex.

Reflex periosteal- see Reflex periosteal.

Nasopalpebral reflex(r. nasopalpebralis; lat. nasus nose + palpebra eyelid) - physiological P.: closing of the eyelids with a slight tapping on the back of the nose or pressure on it.

Reflex palatine-cardiac. (r. palatocardiacus) - vegetative R.: increased heart rate with pressure on the hard palate.

Reflex palatine(r. palatalis) - physiological P.: raising the soft palate and tongue with mechanical irritation of the soft palate.

Nasal reflex(r. nasomentalis; synonym:, Flatau reflex) - R. oral automatism: contraction of the muscles of the chin when hitting the back of the nose with a hammer.

Reflex situational- a change in the development of any conditional R. when the environment changes.

Reflex defensive(r. protectivus) - see Protective reflex.

Reflex oculocardial(r. oculocardiacus; lat. oculus eye + Greek kardia) - see Oculocardial reflex.

Reflex oculo-ocular(r. oculoocularis; lat. oculus eye) - vegetative P.: increased intraocular pressure in the intact eye with hypertension in the other eye, caused by exposure to any stimulus (pain, thermal, chemical, etc.).

Reflex optomotor fusion(Greek optikos referring to vision + lat. motor leading to; synonym: R. fusion, R. fusion) - motor R. in the form of friendly movements of the eyeballs that occur with simultaneous stimulation of functionally different (disparate) points of the retina of the right and left eyes and leading to the projection of the image of the stimulus object on the corresponding points of the retina; provides binocular vision.

Reflex of oral automatism- stretching of the lips or the appearance of sucking movements when some parts of the body are irritated, mainly the face; for children of the first year of life are physiological P., later manifestations of pseudo-bulbar palsy.

Reflexes indicative- P., arising from a sudden change in the environment and accompanied by the activation of analyzers and the mobilization of energy resources.

Reflex orthostatic(r. orthostaticus) - physiological vegetative P.: increased heart rate by 8-12 beats per 1 min. when changing the position of the human body from horizontal to vertical, for example, when getting out of bed.

Reflex paradoxical(r. paradoxalis) - P., which is expressed by a perverted (often opposite) effect compared to the normally occurring R. (for example, contraction of the flexors during irritation of the extensor tendons and vice versa).

Reflexes are pathological- the common name of P., found in an adult with damage to the pyramidal tract (in young children, such R. are normal).

Reflex periosteal(r. periostalis; synonym R. periosteal) - physiological P.: contraction of certain muscles during mechanical irritation of the periosteum, for example, when struck with a mallet.

Reflex peripheral(r. periphericus) - vegetative P., carried out through the ganglia of the autonomic nervous system without direct participation of the central nervous system.

Reflex peroneofemoral(r. peroneofernofalis; anat. peroneus peroneal + lat. fetnur thigh) - see Reflex from the biceps femoris.

Saw-motor reflex(r. pilomotorius; lat. pilus hair + motor setting in motion; syn. R. hairy) - vegetative R.: contraction of the muscles that lift, with mechanical or thermal irritation of skin receptors; manifested by the appearance of goose bumps.

Food reflex(r. alimentarius) - the general name of vegetative R., manifested by a change in the functional state of the digestive organs under the action of a food stimulus.

Plantar reflex(r. plantaris; lat. planta sole) - see Reflex plantar.

Reflex pleuropulmonary(r. pleuropulmonalis; anat. pleura + pulmo, pulmonis lung) - visceral R.: spasm of the bronchial muscles and blood vessels of the lungs with irritation of the pleura receptors.

Reflex chin(r. mentalis; synonym: R. mental-mental) - R. oral automatism: contraction of the chin muscles when hitting the chin with a hammer.

Reflex plantar(r. plantaris; syn. R.) - physiological P.: plantar flexion of the toes with dashed irritation of the skin of its plantar surface at the outer edge.

Reflex postural- see Postural reflex.

Reflex search(syn.) - physiological R. in children under the age of 2 months: stretching the lips, deflecting the tongue and turning the head in the direction of skin irritation in the nasolabial fold.

Reflex polysynaptic(Greek poly many + Synapse) - P., the reflex arc of which has one or more intercalary neurons.

Reflex postural(r. posturalis; synonym: R. postural, R.) - the common name of P., ensuring the maintenance of a certain position in space of the whole body or part of it (for example, limbs).

Pressor reflex(r. pressorius; lat. presso to press, reap) - the common name of P., leading to an increase in blood pressure.

Reflex acquired- see Reflex conditional.

Reflex pronator(r. pronatorius; anat. musculus pronator pronator) - physiological P.: pronation of the hand and forearm when struck with a hammer on the round pronator in the region of the medial condyle of the humerus.

Reflex proprioceptive(r. proprioceptivus) - the common name for P., manifested by contraction of skeletal muscles during stimulation of proprioceptors.

Reflex vesicular- visceral P.: contraction of the gallbladder when the mucous membrane of the duodenum is irritated by some food irritants (for example, vegetable oils) or specially administered substances (for example, magnesium sulfate solution).

Pupillomotor reflex(r. pupillomotorius; anat. pupilla pupil + lat. motor setting in motion) - see Pupil reflex.

Reflex metacarpal-radial(r. meta-carporadialis) - see Radial reflex.

Reflex radiopronator(r. radiopronatorius; anat. radius radius + musculus pronator pronator) - see Radial reflex.

Reflex extensor-ulnar- see Reflex from the triceps muscle of the shoulder.

Cross extensor reflex(syn.) - extension of a bent leg with passive flexion of the other leg in the hip and knee joints; observed with spastic paraparesis of the lower extremities as a pathological protective P., as well as in the norm - in young children.

Stretch reflex(syn. R. myostatic - nrk) - the common name of P., manifested by contraction of the skeletal muscle in response to its passive or active stretching.

Reflex vomiting(r. vomificus) - physiological P.: the occurrence of vomiting or the urge to it with mechanical irritation of the receptors of the posterior pharyngeal wall.

Costal reflex(r. costalis; syn.) - physiological P.: unilateral contraction of the muscles of the upper part of the abdominal wall when struck with a hammer on the edge of the costal arch.

Reflexes are segmental(r. segmentarii) - P., the reflex arc of which closes at the level of one or more neighboring segments of the spinal cord, for example, tendon R.

Reflex carotid sinus(r. sinocaroticus; anat. sinus caroticus) - the common name of P., arising from irritation of receptors located in the carotid sinus.

Reflex scapuloperiosteal Steinhausen(anat. scapula + periosteum periosteum) - see Reflex scapular.

Reflex of the zygomatic(r. zygomaticus) - pathological P.: lower jaw towards hemiplegia when tapping along the zygomatic arch from the same side.

fusion reflex- see Reflex optomotor fusion.

Solar reflex(r. solaris; anat. obsolete plexus solaris solar plexus; synonym: R. epigastric,) - vegetative R.: slowing of the pulse and a decrease in blood pressure when pressing on the abdominal wall between the navel and the xiphoid process (area of the celiac plexus).

Somatic reflex(r. somaticus) - the common name for P., manifested by a change in the tone of skeletal muscles or their contraction during any effects on the body.

Somatovegetative reflex(r. somatovegetativus) - P., arising from irritation of the receptors of the skin, mucous membranes and musculoskeletal system and carried out with the participation of the autonomic nervous system.

Somatovisceral reflex(r. somatovisceralis) - P., manifested by a change in the function of internal organs when receptors of the skin or musculoskeletal system are irritated.

Reflex sucking- Physiological R. in newborns: rhythmic movements of the lips, tongue and muscles of the walls of the oral cavity during irritation of the receptors of the mucous membrane of the lips or surrounding skin; provides the act of sucking.

Reflex vascular(r. vascularis) - vegetative P., manifested by a change in the tone of blood vessels.

Reflex of spinal automatism- see Protective reflex.

Spinal reflexes(r. spinales) - P., the reflex arc of which closes in the spinal cord without the participation of the overlying sections of the central nervous system.

Spinoadductor reflex McCarthy- see Reflex adductor dorsal.

Reflex static(r. staticus; Greek statikos occupying a certain position) - see Postural reflex.

Reflexes are statokinetic(r. statokinetici; Greek statos referring to a certain position + kinēsis movement) - P., ensuring the balance of the body during its active and passive movement in space.

Stem reflexes- P., the reflex arc of which closes in the nuclei of the brain stem.

Reflex styloradial(r. styloradialis; anat. processus styloideus radii of the radius) - see Radial reflex.

Tendon reflex(r. tendinis) - physiological P.: muscle contraction during mechanical stimulation, for example, when struck with a hammer.

Reflex telereceptive(r. telereceptivus) is the common name for physiological P. arising from stimulation of distant receptors (visual, auditory, olfactory).

Tibioadductor reflex(r. tibioadductorius; anat. tibia tibia + musculus adductor adductor muscle; syn. R. tibiofemoral) - physiological R.: adduction of the thigh during tapping along the lower part of the tibia.

Reflex tibiofemoral(r. tibiofemoralis; anat. tibia tibia + femur thigh) - see Tibioadductor reflex.

Reflex Tom- see Pendulum knee reflex.

Reflex tonic(r. tonicus) - the common name of P., expressed by a change in muscle tone.

Reflex tonic palmar(r. tonicus palmaris) - flexion of the fingers of the supinated hand with an increase in the concavity of the palm with repeated stroke stimulation of the palm in the direction from the hypothenar to the base of the thumb; observed with damage to the premotor region of the frontal lobe of the brain on the opposite side.

Reflex tonic cervical(r. tonicus cervicalis) - postural P.: change in the tone of the muscles of the neck, trunk and limbs when the position of the head changes.

Reflex tonic cervical asymmetric(r. tonicus cervicalis asymmetricus) - an increase in the tone of the extensors of the limbs on the side to which it is turned, with a simultaneous increase in the tone of the flexors of the limbs on the other side; physiological postural R. in children under the age of 3 months, at a later age - a symptom of cerebral palsy.

Reflex tonic cervical symmetrical(r. tonicus cervicalis symmetricus) - increased tone of the flexors of the upper and extensors of the lower extremities when the head is tilted forward; physiological postural R. in children under the age of 3 months, at a later age - a symptom of cerebral palsy.

Reflex from the triceps muscle of the shoulder(r. musculi tricipitis brachii; synonym R. extensor-ulnar) - physiological P.: extension of the forearm when the hammer strikes the tendon of the triceps muscle.

Reflex trigeminopupillary(r. trigeminopupillaris; anat. nervus trigeminus trigeminal nerve + pupilla pupil) - see Pupillary trigeminal reflex.

1.1 The role of physiology in the materialistic understanding of the essence of life. The significance of the works of I.M. Sechenov and I.P. Pavlov in the creation of the materialistic foundations of physiology.
2.2 Stages of development of development of physiology. Analytical and systematic approach to the study of body functions. Method of acute and chronic experiment.
3.3 Definition of physiology as a science. Physiology as a scientific basis for diagnosing health and predicting the functional state and performance of a person.
4.4 Definition of physiological function. Examples of the physiological functions of cells, tissues, organs and body systems. Adaptation is the main function of the organism.
5.5 Concept of regulation of physiological functions. Mechanisms and methods of regulation. The concept of self-regulation.
6.6 Basic principles of the reflex activity of the nervous system (determinism, analysis, synthesis, unity of structure and function, self-regulation)
7.7 Definition of a reflex. Classification of reflexes. The modern structure of the reflex arc. Feedback, its meaning.
8.8 Humoral connections in the body. Characterization and classification of physiologically and biologically active substances. Interrelation of nervous and humoral mechanisms of regulation.
9.9 PK Anokhin's teaching about functional systems and self-regulation of functions. Nodal mechanisms of functional systems, general scheme
10.10 Self-regulation of the constancy of the internal environment of the body. The concept of homeostasis and homeokinesis.
11.11 Age features of the formation and regulation of physiological functions. Systemogenesis.
12.1 Irritability and excitability as the basis of tissue response to irritation. The concept of the stimulus, types of stimuli, characteristics. The concept of the threshold of irritation.
13.2 Laws of irritation of excitable tissues: the value of the strength of the stimulus, the frequency of the stimulus, its duration, the steepness of its growth.
14.3 Modern ideas about the structure and function of membranes. Membrane ion channels. Ionic cell gradients, mechanisms of origin.
15.4 Membrane potential, the theory of its origin.
16.5. Action potential, its phases. Dynamics of membrane permeability in different phases of the action potential.
17.6 Excitability, methods for its assessment. Changes in excitability under the action of direct current (electrotone, cathodic depression, accommodation).
18.7 The ratio of the phases of the change in excitability during excitation with the phases of the action potential.
19.8 Structure and classification of synapses. The mechanism of signal transmission in synapses (electrical and chemical) Ionic mechanisms of postsynaptic potentials, their types.
20.10 Definition of mediators and synoptic receptors, their classification and role in the conduction of signals in excitatory and inhibitory synapses.
21Determination of mediators and synaptic receptors, their classification and role in the conduction of signals in excitatory and inhibitory synapses.
22.11 Physical and physiological properties of muscles. Types of muscle contractions. Strength and muscle work. The law of strength.
23.12 Single contraction and its phases. Tetanus, factors affecting its magnitude. Concept of optimum and pessimum.
24.13 Motor units, their classification. Role in the formation of dynamic and static contractions of skeletal muscles in vivo.
25.14 Modern theory of muscle contraction and relaxation.
26.16 Features of the structure and functioning of smooth muscles
27.17 The laws of conducting excitation along the nerves. The mechanism of nerve impulse conduction along unmyelinated and myelinated nerve fibers.
28.17 Sensory receptors, concept, classification, basic properties and features. Excitation mechanism. The concept of functional mobility.
29.1 Neuron as a structural and functional unit in the CNS. Classification of neurons according to structural and functional features. The mechanism of penetration of excitation in the neuron. Integrative function of a neuron.
Question 30.2 Definition of the nerve center (classical and modern). Properties of nerve centers due to their structural links (irradiation, convergence, aftereffect of excitation)
Question 32.4 Inhibition in the central nervous system (I.M. Sechenov). Modern ideas about the main types of central inhibition of postsynaptic, presynaptic and their mechanisms.
Question 33.5 Definition of coordination in the CNS. The main principles of the coordination activity of the central nervous system: reciprocity, a common "final" path, dominant, temporal connection, feedback.
Question 35.7 The medulla oblongata and the bridge, the participation of their centers in the processes of self-regulation of functions. Reticular formation of the brainstem and its descending influence on the reflex activity of the spinal cord.
Question 36.8 Physiology of the midbrain, its reflex activity and participation in the processes of self-regulation of functions.
37.9 The role of the midbrain and medulla oblongata in the regulation of muscle tone. Decerebrate rigidity and the mechanism of its occurrence (gamma-rigidity).
Question 38.10 Static and statokinetic reflexes. Self-regulatory mechanisms to maintain body balance.
Question 39.11 Physiology of the cerebellum, its influence on the motor (alpha-rigidity) and vegetative functions of the body.
40.12 Ascending activating and inhibitory influences of the reticular formation of the brain stem on the cerebral cortex. The role of rf in the formation of the integral activity of the body.
Question 41.13 Hypothalamus, characteristics of the main nuclear groups. The role of the hypothalamus in the integration of autonomic, somatic and endocrine functions, in the formation of emotions, motivations, stress.
Question 42.14 Limbic system of the brain, its role in the formation of motivations, emotions, self-regulation of autonomic functions.
Question 43.15 Thalamus, functional characteristics and features of the nuclear groups of the thalamus.
44.16. The role of the basal nuclei in the formation of muscle tone and complex motor acts.
45.17 Structural and functional organization of the cerebral cortex, projection and associative zones. Plasticity of the functions of the cortex.
46.18 Functional asymmetry of the cerebral cortex, dominance of the hemispheres and its role in the implementation of higher mental functions (speech, thinking, etc.)
47.19 Structural and functional features of the autonomic nervous system. Mediators of vegetative NS, the main types of receptor substances.
48.20 Departments of autonomic NS, relative physiological antagonism and biological synergism of their influences on the innervated organs.
49.21 Regulation of vegetative functions (CBF, limbic system, hypothalamus) of the body. Their role in the vegetative provision of goal-directed behavior.
50.1 Determination of hormones, their formation and secretion. Action on cells and tissues. Classification of hormones according to different criteria.
51.2 Hypothalamo-pituitary system, its functional connections. Trans and para pituitary regulation of the endocrine glands. The mechanism of self-regulation in the activity of endocrine glands.
52.3 Pituitary hormones and their participation in the regulation of endocrine organs and body functions.
53.4 Physiology of the thyroid and parathyroid glands. Neurohumoral mechanisms of regulation of their functions.
55.6 Physiology of the adrenal glands. The role of hormones of the cortex and medulla in the regulation of body functions.
56.7 Sex glands. Male and female sex hormones and their physiological role in the formation of sex and the regulation of reproductive processes.
57.1 The concept of the blood system (Lang), its properties, composition, functions. Blood composition. Basic physiological constants of blood and mechanisms of their maintenance.
58.2 Composition of blood plasma. The osmotic pressure of the blood is fs, which ensures the constancy of the osmotic pressure of the blood.
59.3 Blood plasma proteins, their characteristics and functional significance. Oncotic pressure in blood plasma.
60.4 PH of the blood, physiological mechanisms that maintain the constancy of acid-base balance.
61.5 Erythrocytes, their functions. Counting methods. Types of hemoglobin, its compounds, their physiological significance. Hemolysis.
62.6 Regulation of erythro and leukopoiesis.
63.7 The concept of hemostasis. The process of blood coagulation and its phases. Factors accelerating and slowing down blood coagulation.
64.8 Vascular-platelet hemostasis.
65.9 Coagulating, anticoagulant and fibrinolytic blood system, as the main components of the apparatus of the functional system for maintaining the liquid state of the blood
66.10 The concept of blood groups. Avo and Rh factor systems. Determination of the blood group. Rules for blood transfusion.
67.11 Lymph, its composition, functions. Non-vascular liquid media, their role in the body. Water exchange between blood and tissues.
68.12 Leukocytes and their types. Counting methods. Leukocyte formula. Functions of leukocytes.
69.13 Platelets, number and functions in the body.
70.1 Importance of blood circulation for the body.
71.2 Heart, the meaning of its chambers and valve apparatus. Cardiocycle and its structure.
73. PD of cardiomyocytes
74. The ratio of excitation, excitability and contraction of the cardiomyocyte in different phases of the cardiocycle. Extrasystoles
75.6 Intracardiac and extracardiac factors involved in the regulation of the activity of the heart, their physiological mechanisms.
Extracardiac
Intracardiac
76. Reflex regulation of the activity of the heart. Reflex zones of the heart and blood vessels. Intersystemic cardiac reflexes.
77.8 Auscultation of the heart. Heart sounds, their origin, places of listening.
78. Basic laws of hemodynamics. Linear and volumetric blood flow velocity in various parts of the circulatory system.
79.10 Functional classification of blood vessels.
80. Blood pressure in various parts of the circulatory system. Factors determining its value. Types of blood pressure. The concept of mean arterial pressure.
81.12 Arterial and venous pulse, origin.
82.13 Physiological features of blood circulation in the myocardium, kidneys, lungs, brain.
83.14 The concept of basal vascular tone.
84.Reflex regulation of systemic arterial pressure. The value of vascular reflexogenic zones. Vasomotor center, its characteristics.
85.16 Capillary blood flow and its features. Microcirculation.
89. Bloody and bloodless methods for determining blood pressure.
91. Comparison of ekg and fkg.
92.1 Breathing, its essence and main stages. Mechanisms of external respiration. Biomechanics of inhalation and exhalation. Pressure in the pleural cavity, its origin and role in the mechanism of lung ventilation.
93.2 Gas exchange in the lungs. Partial pressure in gases (oxygen and carbon dioxide) in the alveolar air and tension of gases in the blood. Methods of analysis of blood and air gases.
94. Oxygen transport by blood. Oxyhemoglobin dissociation curve. Influence of various factors on the affinity of hemoglobin to oxygen. Oxygen capacity of blood. Oxygemometry and oxyhemography.
98.7 Methods for determining lung volumes and capacities. Spirometry, spirography, pneumotachometry.
99 Respiratory center. Modern presentation and its structure and localization. Autonomy of the respiratory center.
101 Self-regulation of the respiratory cycle, mechanisms of change of respiratory phases. The role of peripheral and central mechanisms.
102 Humoral effects on respiration, the role of carbon dioxide and pH levels. The mechanism of the first breath of a newborn. The concept of respiratory analeptics.
103.12 Breathing under conditions of low and high barometric pressure and changes in the gaseous environment.
104. Phs ensuring the constancy of the gas composition of the blood. Analysis of its central and peripheral components
105.1. Digestion, its importance. Functions of the digestive tract. Research in the field of digestion by I.P. Pavlova. Methods for studying the functions of the gastrointestinal tract in animals and humans.
106.2. Physiological basis of hunger and satiety.
107.3. Principles of regulation of the digestive system. The role of reflex, humoral and local mechanisms of regulation. Gastrointestinal hormones.
108.4. Digestion in the mouth. Self-regulation of the chewing act. The composition and physiological role of saliva. Regulation of salivation. The structure of the reflex arc of salivation.
109.5. Swallowing his self-regulation phase of this act. Functional features of the esophagus.
110.6. Digestion in the stomach. Composition and properties of gastric juice. Regulation of gastric secretion. Phases of the separation of gastric juice.
111.7. Digestion in the duodenum. Exocrine activity of the pancreas. Composition and properties of pancreatic juice. regulation of pancreatic secretion.
112.8. The role of the liver in digestion: barrier and bile-forming functions. Regulation of the formation and secretion of bile into the duodenum.
113.9.Motor activity of the small intestine and its regulation.
114.9. Abdominal and parietal digestion in the small intestine.
115.10. Features of digestion in the colon, motility of the colon.
116 fs, ensuring the constancy of the pit. Thing in the blood. Analysis of central and peripheral components.
117) The concept of metabolism in the body. Processes of assimilation and dissimilation. Plastic energy role of nutrients.
118) Methods for determining energy consumption. Direct and indirect calorimetry. Determination of the respiratory coefficient, its value for determining energy expenditure.
119) Basic metabolism, its significance for the clinic. Conditions for measuring basal metabolism. Factors affecting the value of the main exchange.
120) Energy balance of the body. Work exchange. Energy costs of the body in different types of labor.
121) Physiological nutritional norms depending on age, type of work and the state of the organism.Principles of compiling food rations.
122. The constancy of the temperature of the internal environment of the body as a condition for the normal course of metabolic processes ....
123) Human body temperature and its daily fluctuations. The temperature of various parts of the skin and internal organs. Nervous and humoral mechanisms of thermoregulation.
125) Heat dissipation. Methods for transferring heat from the surface of the body. Physiological mechanisms of heat transfer and their regulation
126) The excretory system, its main organs and their participation in maintaining the most important constants of the internal environment of the body.
127) Nephron as a structural and functional unit of the kidney, structure, blood supply. The mechanism of formation of primary urine, its quantity and composition.
128) The formation of the final urine, its composition. Reabsorption in tubules, mechanisms of its regulation. The processes of secretion and excretion in the renal tubules.
129) Regulation of kidney activity. The role of nervous and humoral factors.
130. Methods for assessing the value of filtration, reabsorption and secretion of the kidneys. The concept of the coefficient of purification.
131.1 Pavlov's doctrine of analyzers. The concept of sensory systems.
132.3 Conductor department of analyzers. The role and participation of switching nuclei and the reticular formation in the conduction and processing of afferent excitations
133.4 Cortical department of analyzers. Processes of higher cortical analysis of afferent excitations. Interaction of analyzers.
134.5 Adaptation of the analyzer, its peripheral and central mechanisms.
135.6 Characteristics of the visual analyzer. Receptor apparatus. Photochemical processes in the retina under the action of light. Perception of the world.
136.7 Modern ideas about the perception of light. Methods for studying the function of the visual analyzer. The main forms of color vision impairment.
137.8 Auditory analyzer. Sound-catching and sound-conducting apparatus. Receptor section of the auditory analyzer. Mechanism of the appearance of the receptor potential in the hair cells of the spinal organ.
138.9. Theory of sound perception. Methods of studying the auditory analyzer.
140.11 Physiology of the taste analyzer. Receptor, conduction and cortical sections. Classification of taste sensations. Methods for studying the taste analyzer.
141.12 Pain and its biological significance. The concept of nociception and the central mechanisms of pain. Actinociceptive system. Neurochemical mechanisms of actinociception.
142. The concept of the anti-pain (antinociceptive) system. Neurochemical mechanisms of antinociception, roleendorphins and exorphins.
143. Conditioned reflex as a form of adaptation of animals and humans to changing conditions of life ....
Rules for the development of conditioned reflexes
Classification of conditioned reflexes
144.2 Physiological mechanisms of formation of conditioned reflexes. Classical and modern ideas about the formation of temporary connections.
Reflex- the main form of nervous activity. The response of the body to irritation from the external or internal environment, carried out with the participation of the central nervous system, is called reflex.
According to a number of features, reflexes can be divided into groups
Unconditioned reflexes- hereditarily transmitted (congenital) reactions of the body, inherent in the whole species. They perform a protective function, as well as the function of maintaining homeostasis (adaptation to environmental conditions).
Unconditioned reflexes are an inherited, invariable reaction of the body to external and internal signals, regardless of the conditions for the occurrence and course of reactions. Unconditioned reflexes ensure the adaptation of the organism to unchanging environmental conditions. The main types of unconditioned reflexes: food, protective, indicative, sexual.
An example of a protective reflex is the reflex withdrawal of the hand from a hot object. Homeostasis is maintained, for example, by a reflex increase in breathing with an excess of carbon dioxide in the blood. Almost every part of the body and every organ is involved in reflex reactions.
The simplest neural networks, or arcs (as Sherrington puts it), involved in unconditioned reflexes, are closed in the segmental apparatus of the spinal cord, but can be closed even higher (for example, in the subcortical ganglia or in the cortex). Other parts of the nervous system are also involved in reflexes: the brainstem, cerebellum, cerebral cortex.
Arcs of unconditioned reflexes are formed by the time of birth and persist throughout life. However, they can change under the influence of the disease. Many unconditioned reflexes appear only at a certain age; Thus, the grasping reflex characteristic of newborns fades at the age of 3-4 months.
Conditioned reflexes arise in the course of individual development and the accumulation of new skills. The development of new temporary connections between neurons depends on the environmental conditions. Conditioned reflexes are formed on the basis of unconditioned ones with the participation of higher parts of the brain.
The development of the doctrine of conditioned reflexes is associated primarily with the name of IP Pavlov. He showed that a new stimulus can start a reflex reaction if it is presented for some time together with an unconditioned stimulus. For example, if a dog is allowed to smell meat, then gastric juice is secreted from it (this is an unconditioned reflex). If, however, the bell is ringed simultaneously with meat, then the dog's nervous system associates this sound with food, and gastric juice will be released in response to the bell, even if meat is not presented. Conditioned reflexes underlie acquired behavior
reflex arc(nervous arch) - the path traversed by nerve impulses during the implementation of the reflex
The reflex arc consists of six components: receptors, afferent pathway, reflex center, efferent pathway, effector (working organ), feedback.
Reflex arcs can be of two types:
1) simple - monosynaptic reflex arcs (reflex arc of the tendon reflex), consisting of 2 neurons (receptor (afferent) and effector), there is 1 synapse between them;
2) complex - polysynaptic reflex arcs. They include 3 neurons (there may be more) - receptor, one or more intercalary and effector.
The feedback loop establishes a connection between the realized result of the reflex reaction and the nerve center that issues executive commands. With the help of this component, the open reflex arc is transformed into a closed one.
Rice. 5. Reflex arc of the knee jerk:
1 - receptor apparatus; 2 - sensitive nerve fiber; 3 - intervertebral node; 4 - sensitive neuron of the spinal cord; 5 - motor neuron of the spinal cord; 6 - motor nerve fiber

"

Reflex- the response of the body is not an external or internal irritation, carried out and controlled by the central nervous system. The development of ideas about human behavior, which has always been a mystery, was achieved in the works of Russian scientists I. P. Pavlov and I. M. Sechenov.

Reflexes unconditioned and conditional.

Unconditioned reflexes- these are innate reflexes that are inherited by offspring from parents and persist throughout a person's life. Arcs of unconditioned reflexes pass through the spinal cord or brain stem. The cerebral cortex does not participate in their formation. Unconditioned reflexes provide only those changes in the environment that many generations of a given species often encountered.

To include:

Food (salivation, sucking, swallowing);
Defensive (coughing, sneezing, blinking, pulling the hand away from a hot object);
Approximate ( skew eyes, turns);
Sexual (reflexes associated with reproduction and care of offspring).
The significance of unconditioned reflexes lies in the fact that thanks to them the integrity of the body is preserved, the maintenance of constancy and reproduction occurs. Already in a newborn child, the simplest unconditioned reflexes are observed.
The most important of these is the sucking reflex. The irritant of the sucking reflex is the touch of an object on the child's lips (mother's breasts, nipples, toys, fingers). The sucking reflex is an unconditioned food reflex. In addition, the newborn already has some protective unconditioned reflexes: blinking, which occurs if a foreign body approaches the eye or touches the cornea, constriction of the pupil when strong light is applied to the eyes.

Particularly pronounced unconditioned reflexes in various animals. Not only individual reflexes can be innate, but also more complex forms of behavior, which are called instincts.

Conditioned reflexes- these are reflexes that are easily acquired by the body during life and are formed on the basis of an unconditioned reflex under the action of a conditioned stimulus (light, knock, time, etc.). IP Pavlov studied the formation of conditioned reflexes in dogs and developed a method for obtaining them. To develop a conditioned reflex, a stimulus is needed - a signal that triggers a conditioned reflex, repeated repetition of the action of the stimulus allows you to develop a conditioned reflex. During the formation of conditioned reflexes, a temporary connection arises between the centers and centers of the unconditioned reflex. Now this unconditioned reflex is not carried out under the influence of completely new external signals. These irritations from the outside world, to which we were indifferent, can now become of vital importance. During life, many conditioned reflexes are developed, which form the basis of our life experience. But this life experience makes sense only for this individual and is not inherited by its descendants.

into a separate category conditioned reflexes allocate motor conditioned reflexes developed during our life, i.e. skills or automated actions. The meaning of these conditioned reflexes is the development of new motor skills, the development of new forms of movements. During his life, a person masters many special motor skills associated with his profession. Skills are the basis of our behavior. Consciousness, thinking, attention are freed from performing those operations that have become automated and become habits of everyday life. The most successful way to master skills is through systematic exercises, correcting mistakes noticed in time, knowing the ultimate goal of each exercise.

If the conditioned stimulus is not reinforced for some time by the unconditioned stimulus, then the conditioned stimulus is inhibited. But it doesn't disappear completely. When the experiment is repeated, the reflex is very quickly restored. Inhibition is also observed under the influence of another stimulus of greater force.

Structural-functional. The unit of the CNS is the neuron. It consists of a body (soma) and processes - numerous dendrites and one axon. Dendrites usually branch strongly and form many synapses with other cells, which determines their leading role in the perception of information by the neuron. In most central neurons, AP occurs in the area of the axon hillock membrane, the excitability of which is twice as high as other areas, and from here the excitation spreads along the axon and the cell body. This method of excitation of a neuron is important for its implementation, an integrative function, i.e. the ability to sum up the influences coming to the neuron through different synaptic pathways.

The degree of excitability of different parts of the neuron is not the same, it is highest in the region of the axon hillock, in the region of the body of the neuron it is much lower, and the lowest in dendrites.

In addition to neurons in the CNS, there are glial cells, which occupy half the volume of the brain. Peripheral axons are also surrounded by a sheath of glial cells - Schwann cells. Neurons and glial cells are separated by intercellular clefts that communicate with each other and form a fluid-filled intercellular space of neurons and glia. Through this space there is an exchange of substances between nerve and glial cells. The functions of glial cells are diverse: they are the supporting, protective and trophic apparatus for neurons, maintain a certain concentration of calcium and potassium ions in the intercellular space; actively absorb neurotransmitters, thus limiting the duration of their action.

The main mechanism of the activity of the central nervous system is the reflex. Reflex- is the response of the body to the actions of the stimulus, carried out with the participation of the central nervous system. Reflex in Latin means "reflection". For the first time the term "reflection" or "reflecting" was used by R. Descartes (1595-1650) to characterize the body's reactions in response to irritation of the senses. He was the first to suggest that all manifestations of the effector activity of the organism are caused by quite real physical factors. After R. Descartes, the idea of a reflex was developed by the Czech researcher G. Prochazka, who developed the doctrine of reflective actions. At that time, it was already noted that in spinal animals, movements occur in response to irritation of certain areas of the skin, and the destruction of the spinal cord leads to their disappearance.

Further development of the reflex theory is associated with the name of I.M. Sechenov. In his book Reflexes of the Brain, he argued that all acts of unconscious and conscious life are by nature reflexes. It was a brilliant attempt to introduce physiological analysis into mental processes. But at that time there were no methods for an objective assessment of brain activity that could confirm this assumption of I.M. Sechenov. Such an objective method was developed by I.P. Pavlov - the method of conditioned reflexes, with the help of which he proved that the higher nervous activity of the body, like the lower one, is reflex.

The structural basis of the reflex, its material substrate (morphological basis) is the reflex path (reflex arc).

Rice. Scheme of the structure of reflections.

1 - receptor;

2 - afferent nerve pathway;

3 - nerve center;

4 - efferent nerve pathway;

5 - working body (effector);

6 - reverse afferentation

At the heart of the modern idea of reflex activity is the concept of a useful adaptive result, for the sake of which any reflex is performed. Information about the achievement of a useful adaptive result enters the central nervous system through the feedback link in the form of reverse afferentation, which is an obligatory component of reflex activity. The principle of reverse afferentation was introduced into the reflex theory by P.K. Anokhin. Thus, according to modern concepts, the structural basis of the reflex is not a reflex arc, but a reflex ring, consisting of the following components (links): receptor, afferent nerve pathway, nerve center, efferent nerve pathway, working organ (effector), back afferent channel.

Analysis of the structural basis of the reflex is carried out by successively turning off individual links of the reflex ring (receptor, afferent and efferent pathways, nerve center). When any link of the reflex ring is turned off, the reflex disappears. Consequently, for the implementation of the reflex, the integrity of all links of its morphological basis is necessary.

(lat. reflexus - turned back, reflected) - the response of the body to certain influences carried out through the nervous system. Distinguish R. unconditional (congenital) and conditional (acquired by the body during an individual life, having the property of disappearing and recovering). Fr. the philosopher R. Descartes was the first to point out the reflex principle in the activity of the brain. N.D. Naumov

Great Definition

Incomplete definition ↓

REFLEX

from lat. reflexus - turning back; in a figurative sense - reflection) - the general principle of regulating the behavior of living systems; engine (or secretory) act, having will accommodate. value determined by the action of signals on receptors and mediated by nerve centers. The concept of R. was introduced by Descartes and served the task of deterministically explaining, within the framework of mechanistic. pictures of the world, the behavior of organisms based on the general laws of physics. interactions of macrobodies. Descartes rejected the soul as explained. motor principle. activity of the animal and described this activity as the result of a strictly natural response of the "machine-body" to external influences. Based on the mechanistically understood principle of R., Descartes tried to explain some mental. functions, in particular learning and emotions. All subsequent neuromuscular physiology was under the decisive influence of the doctrine of R. Nek-rye followers of this doctrine (Dilli, Swammerdam) back in the 17th century. speculated about the reflex nature of all human behavior. This line was completed in the 18th century. La Mettrie. Ch. deterministic opponent. Vitalism (Stahl and others) came out with a look at R., arguing that not a single organic. the function is not carried out automatically, but everything is directed and controlled by the sentient soul. In the 18th century Witt discovered that a segment of the spinal cord is sufficient for the implementation of an involuntary muscular reaction, but he considered its determinant to be a special "sensitive principle". The problem of the dependence of movement on sensation, used by Witt to prove the primacy of feeling in relation to the work of the muscle, materialistic. the interpretation was given by Hartley, who pointed out that sensation really precedes motion, but it is itself due to a change in the state of moving matter. Opening specific. signs of neuromuscular activity prompted naturalists to introduce the concept of “forces” inherent in the body and distinguishing it from other natural bodies (“muscle and nerve force” by Haller, “nerve force” by Unzer and Prochasky), and the interpretation of force was materialistic. Creatures. the contribution to the further development of the doctrine of R. was made by Prohaska, who proposed biological. R.'s explanation as an expedient act, regulated by a sense of self-preservation, under the influence of which the body evaluates external stimuli. The development of the anatomy of the nervous system led to the discovery of the mechanism of the simplest reflex arc (the Bell-Magendie law). There is a scheme of localization of reflex ways, on the basis of a cut in the 30th. 19th century maturing classic. teaching about R. as the principle of operation of the spinal centers, in contrast to the higher parts of the brain. It was substantiated by Marshall Hall and I. Muller. This is purely physiological. doctrine exhaustively explained the definition. category of nervous acts by the influence of an external stimulus on a specific. anatomical structure. But the idea of R. as a mechanical. "blind" movement, predetermined anatomical. the structure of the organism and independent of what is happening in the external environment, forced to resort to the concept of a force that selects from a set of reflex arcs those needed in given circumstances and synthesizes them into a holistic act in accordance with the object or situation of action. This concept has been subjected to a sharp experiment.-theoretical. criticism from the materialistic positions of Pfluger (1853), who proved that the lower vertebrates, devoid of a brain, are not purely reflex automata, but vary their behavior with changing conditions, which, along with the reflex function, has a sensory one. The weak side of Pfluger's position was the opposition of R. to the sensory function, the transformation of the latter into the final will explain. concept. Sechenov brought R.'s theory onto a new path. The former purely morphological. he transformed R.'s scheme into a neurodynamic one, bringing the connection center to the fore. processes in nature. groups. Feeling of varying degrees of organization and integration was recognized as the regulator of movement - from the simplest sensation to the dissected sensual, and then the minds. an image that reproduces the subject characteristics of the environment. Accordingly, the afferent phase of the interaction of the organism with the environment was not thought of as a mechanical one. contact, but as the acquisition of information that determines the subsequent course of the process. The function of the centers was interpreted in a broad biological sense. adaptation. Engine activity acted as a factor that has a reverse effect on the construction of behavior - external and internal (feedback principle). In the future, a major contribution to the development of physiological. ideas about the mechanism of R. introduced Sherrington, who studied the integrative and adaptive originality of nervous acts. However, in understanding the mental he adhered to dualistic brain functions. views. IP Pavlov, continuing the line of Sechenov, experimentally established the difference between unconditional and conditional R. and discovered the laws and mechanisms of the reflex work of the brain, which forms the physiological. basis of psychic activities. The subsequent study of complex will adapt. acts supplemented the general scheme of R. with a number of new ideas about the mechanism of self-regulation (N. A. Bernshtein, P. K. Anokhin and others). Lit.: Sechenov I. M., Physiology of the nervous system, St. Petersburg, 1866; Bessmertny B.S., One Hundred Years of the Belle Magendie Doctrine, in the book: Archive of Biol. Sciences, vol. 49, no. 1, ?., 1938; Konradi G.P., On the history of the development of the doctrine of R., ibid., vol. 59, no. 3, M., 1940; Anokhin P.K., From Descartes to Pavlov, M., 1945; Pavlov I.P., Izbr. works, M., 1951; Yaroshevsky M. G., History of psychology, M., 1966; W. Gray Walter, The Living Brain, trans. from English, M., 1966; Eckhard C., Geschichte der Entwicklung der Lehre von den Reflexerscheinungen, "Beitr?ge zur Anatomie und Physiologie", 1881, Bd 9; Fulton J. F., Muscular contraction and the reflex control of movement, L., 1926; Fearing F., Reflex action. A study in the history of psychological psychology, L., 1930; Bastholm E., The history of muscle physiology, Copenhagen, 1950. M. Yaroshevsky. Leningrad. The current state of the study of R. Advances in the physiology of the nervous system and close contact between general neurophysiology and the physiology of higher nervous activity with biophysics and cybernetics have greatly expanded and deepened the understanding of R. at the physicochemical, neuronal, and system levels. Physico-chemical level. An electron microscope showed a subtle mechanism of chemical. transfer of excitation from neuron to neuron by emptying the mediator vesicles in the synaptic. cracks (E. de Robertis, 1959). At the same time, the nature of the excitation wave in the nerve is determined, as well as 100 years ago by L. Herman (1868), in the form of a physical. action current, short-time electric impulse (B. Katz, 1961). But along with electrical, metabolic are taken into account. excitatory components, eg. "sodium pump", generating electricity. current (A. Hodgkin and A. Huxley, 1952). neural level. Still Ch. Sherrington (1947) connected nek-ry sv-va simple spinal R., eg. reciprocity of excitation and inhibition, with hypothetical. wiring diagrams for neurons. I. S. Beritashvili (1956) on the basis of cytoarchitectonic. data, he made a number of assumptions about various forms of organization of neurons in the cerebral cortex, in particular, about the reproduction of images of the outside world by the system of stellate cells of the eye. analyzer of lower animals. The general theory of the neural organization of reflex centers was proposed by W. McCulloch and V. Pite (1943), who used the mathematical apparatus. logic for modeling the functions of neural circuits in rigid determinants. networks of formal neurons. However, many Holy Islands of higher nervous activity do not fit into the theory of fixed nervous networks. Based on the results of electrophysiological and morphological. studying the interconnection of neurons in the higher parts of the brain, a hypothesis of their probabilistic-statistical organization is being developed. According to this hypothesis, the regularity of the course of the reflex reaction is ensured not by the uniqueness of the path of signals along fixed interneuronal connections, but by the probabilistic distribution of their flows over sets. ways and statistics. way to achieve the end result. Randomness in the interaction of neurons was assumed by D. Hebb (1949), A. Fessar (1962) and other researchers, and W. Gray Walter (1962) showed statistical. the nature of conditional R. Neural networks with fixed connections are often called deterministic, contrasting them with networks with random connections as indeterministic. However, stochasticity does not mean indeterminism, but, on the contrary, it provides the highest, most flexible form of determinism, apparently, which is the basis of St. Islands. plasticity R. Systemic level. The system of even a simple unconditional R., for example. pupillary, consists of a number of self-regulating subsystems with linear and non-linear operators (M. Clynes, 1963). Assessment of the correspondence between acting stimuli and the “nervous model of the stimulus” (E. N. Sokolov, 1959) turned out to be an important factor in the biologically expedient organization of R. Taking into account the mechanisms of self-regulation by means of feedback, Sechenov (1863) wrote about the presence of which, the structure of R. in modern cybernetic aspect began to be represented not in the form of an open reflex arc, but as a closed reflex ring (N. A. Bernshtein, 1963). Recently, discussions have unfolded about the content of the concepts of signaling, reinforcement and temporal connections of conditional R. Thus, P.K. structures for monitoring the results of action. E. A. Asratyan (1963) emphasizes the qualities. differences in the connections of conditional R. from short-term. reactions such as breaking and dominant. Lit.: Beritashvili I.S., Morphological. and physiological. bases of temporal connections in the cerebral cortex, "Proceedings of the I. S. Beritashvili Institute of Physiology", 1956, v. 10; McCulloch, W.S. and Pitts, W., Logic. calculus of ideas relating to nervous activity, [transl. from English], in collection: Avtomaty, M., 1956; Sokolov E. N., Nervous model of stimulus, "Report. APN of the RSFSR", 1959, No 4; Katz B., The nature of the nerve impulse, in Sat.: Sovr. problems of biophysics, vol. 2, M., 1961; Hartline X., Receptor mechanisms and integration of sensory information in the retina, ibid.; Walter G.W., Statistical. approach to the theory of conditional R., in the book: Electroencephalographic. study of higher nervous activity, M., 1962; Fessar?., Analysis of the closure of temporal connections at the level of neurons, ibid.; Smirnov G.D., Neurons and func. organization of the nerve center, in Sat: Gagra conversations, vol. 4, Tb., 1963; Philos. question physiology of higher nervous activity and psychology, M., 1963 (see articles by P. K. Anokhin, E. A. Asratyan and N. A. Bernshtein); Kogan A. B., Probabilistic-statistical. the principle of neural organization of the functional systems of the brain, DAN SSSR, 1964, v. 154, No 5; Sherrington Ch. S., The integrative action of the nervous system, 1947; Hodgkin A. L., Huxley A. F., A quantitative description of membrane current and its application to conduction and excitation in nerve, "J. physiol.", 1952, v. 117, No 4; Hebb D. O., The organization of behavior, N. Y.–L., ; Robertis Ed. de, Submicroscopic morphology of the synapse, "Intern. Rev. Cytol.", 1959, v. 8, p. 61–96. A. Kogan. Rostov n/a.