Download NERVE AND MUSCLE PHYSIOLOGY UNIT № 1 Topic: General

NERVE AND MUSCLE PHYSIOLOGY
UNIT № 1
Topic: General properties of the excitable tissues; electrical potentials of nerve and muscle cells.
The purpose of the unit: to understand the nature of bioelectrical phenomena in the excitable
tissues.
Questions for Self-preparation
1. Organization of the cell. Membrane structures of the cell.
2. Passive and active transport. Protein ion channels, “gating” of ion channels. Sodiumpotassium pump.
3. Resting membrane potential, ion mechanism. Methodic to measure membrane potential.
4. Nerve action potential. Action potential curve, stages of the action potential, ion mechanism.
5.
The laws of stimulation for excitable tissues. Initiation of the action potential. Threshold for
excitation, “acute local potentials”. All-or-nothing principle.
Practice
1. Reproduction of Galvani’s Experiments.

The first experiment of Galvani (the experiment with metals): Make the neuromuscular
preparation consisting of two frog back paws. Hang it up on copper hook of stand. Touch
the preparation with the plate made from the other metal (the zinc). Observe the muscle
contraction. Try to explain its nature.

The second experiment of Galvani (the contraction without metal): Make the
neuromuscular preparation of the frog back paw. Isolate the sciatic nerve carefully. Cross
the muscles in the lower part of the hip, quickly throw the sciatic nerve simultaneously
upon damaged and undamaged areas of the hip muscles. Observe contraction of the leg
muscles. Try to explain its nature.
2. Secondary Muscle Contraction (Matteucci’s Experiment).
Make two neuromuscular preparations of the frog back paws. Isolate their sciatic nerves. The nerve
of the first preparation place on electrodes united with facilitator and then connect muscles of these
preparations with the sciatic nerve. Switch on the facilitator and observe the muscle contractions on
both paws. Try to explain its reason.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 4-22, 26-28.
UNIT № 2
Topic: Initiation and propagation of the action potential. Neuromuscular junction.
The purpose of the unit: to understand laws of stimulation and propagation of potentials along the
nervous fibers and from nerves to muscles.
Questions for Self-preparation
1. Propagation of the action potential. Direction of propagation. Inhibition of excitability, local
anesthetics.
2. Velocity of conduction in different nerve fibers (by Erlanger, Gasser).
3. Physiologic anatomy of the synapse. Chemical synapse characteristics, neuromuscular
transmission. Synaptic delay.
4. Presynaptic terminals. Transmitter’s release, role of calcium ions.
5. Postsynaptic membrane: ion channels, receptors in the postsynaptic membrane. Action fate
of acetylcholine. Endplate potential.
6. Blockage of neuromuscular transmission. Synaptic fatigue.
Practice
1. Both-side Propagation of Impulses along the Nerve.
Make the neuromuscular preparation of the frog back paw. Isolate the sciatic nerve. Place it on
electrodes united with facilitator. Stimulate the nerve in the middle portion; observe the muscle
contraction on the both sides from the place of stimulation. Try to explain this effect.
2. The Law of Physiological Continuity of the Nerve, Effect of Local Anesthetics.
Make the neuromuscular preparation of the frog back paw. Isolate the sciatic nerve. Place tampons
with 2% solution of lidocain on the middle part of the nerve. Switch on the facilitator; and observe
the absence of the muscle contraction. Then take tampons away, and wash properly the nerve with
the Ringer solution. Observe the muscle contraction after the nerve stimulation.
3. The Law of the Isolated Propagation along Nerve Fibers.
Make the neuromuscular preparation of the frog back paw. Isolate the sciatic nerve and divide it in
separate nervous filaments. Stimulate each filament separately. Observe contraction of the different
muscular groups.
4. Optimum and Pessimism, Results of Rhythmical Stimulation of Rabbit’s Muscle.
Make neuromuscular preparation of the frog back paw. Fix it in miograph and place the electrodes
on the muscle. Observe the differences in the muscle contraction after consequent increasing of the
2
stimuli frequency. Mark the optimum frequency. Mark the reduction of the amplitude of the
contraction when the frequency becomes pessimist.
5. Synaptic Fatigue in a Neuromuscular Preparation.
Fix neuromuscular preparation in miograph. Place electrodes to the nerve and stimulate it with the
electrical current of the average frequency. Observe the gradual reduction of the muscular
contraction amplitude. Replace the electrodes on muscle directly; observe the amplitude of the
muscular contractions during such way of stimulation. Try to explain the observed phenomenon.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006, P. 22-27, 41-46, 353-355,
360.
UNIT № 3
Topic: Contraction of skeletal and smooth muscles.
The purpose of the unit: to study general and molecular mechanisms of muscle contraction.
Questions for Self-preparation
1. Skeletal and smooth muscle fibers. Actin and myosin filaments. Sarcoplasmic reticulum.
2. General and molecular mechanism of contraction. Excitation-contraction coupling. ATP as a
source of energy for contraction. Rigor mortis.
3. Characteristics of whole muscle contraction. Muscle twitches, frequency summation and
tetanization.
4. Mechanics of skeletal muscle contraction. Motor units. Recruitment of motor units.
5. Strength of muscle contraction. Multiple fiber summation. Staircase effect. Effect of muscle
length on the strength of contraction.
6. Energetic of muscle contraction. Muscle fatigue. Muscle hypertrophy and atrophy. Effects
of muscle denervation.
7. Smooth muscles. Effect of nerves and hormones on the smooth muscle.
Practice
1. Multiple Muscle Fiber Summation.
Make neuromuscular preparation of the frog’s gastrocnemius muscle. Fix it in miograph and
place the electrodes to muscle, enlarge the force of stimulation gradually from zero to
maximum. Register muscle contractions; define the current value when the minimal contraction
3
appears. Observe increasing of the muscle contraction while stimulation increases. Fix the
stimulus level when the maximal muscle contraction occurs.
2. Muscle Twitch and Frequency Summation.
Fix neuromuscular preparation in miograph. Switch on the facilitator and stimulate the muscle
with the overthreshold stimuli with frequency 1 Hz, register the muscle twitches. Then increase
the frequency of stimulation from 1 Hz to 200 Hz. Mark the point when frequency summation is
observed.
3. Dynamometery.
Stay straight, one hand aside. Press dynamometer in the hand 10 times with 5-10 seconds
intervals. Right down each result. Calculate maximum strength of muscles and their working
capacity according to the formulae:
P = (f1+f2+f3+…..f10) / 10
where: P – the working capacity; f – the strength of each muscle
contraction;
S = (f1-fmin)/fmax *100% where: S- index of the working capacity
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 29-40, 44-54.
Questions for Colloquium
1. Excitation. Definition of excitability. Excitable tissues. Types of stimuli.
2. Transport mechanisms of the cell membrane. Diffusion through protein channels and
“gating” of these channels. Selective permeability of protein channels.
3. Factors that affect net rate of diffusion (concentration difference, membrane electrical
potential, pressure difference).
4. Sodium-potassium pump. Electrogenic nature of Na-K-pump.
5. Resting membrane potential, ion mechanism. Measuring the membrane potential.
6. Nerve action potential, ion theory. Stages of the action potential.
7. Stimulus strength. Initiation of the action potential. Threshold of excitation. Acute local
potentials, their characteristics. All-or-noting principle.
8. Propagation of the action potential. Direction of propagation. Local anesthetics effect.
9. Physiological classification of nerve fibers.
10. Neuromuscular junction. Presynaptic terminals. Transmitter’s release.
11. Neuromuscular junction. Effect of acetylcholine on the postsynaptic membrane.
4
12. Neuromuscular junction. Role of acetycholinesterase in the synaptic cleft. End plate
potential.
13. Neuromuscular junction. Chemicals that block transmission in neuromuscular junction.
14. Neuromuscular junction in the smooth muscles.
15. General mechanism of muscle contraction. Excitation-contraction coupling.
16. Molecular mechanisms of muscle contraction. Sliding filament theory. Role of the calcium
ions.
17. ATP as a source of energy for muscle contraction. Muscle fatigue.
18. Characteristics of the whole muscle contraction. Isometric versus isotonic contraction.
19. Muscle twitches. Frequency summation and tetanization.
20. Motor unit. Fast versus slow muscle fibers.
21. Strength of muscle contraction. Effect of muscle length. The staircase effect.
22. Contraction of smooth muscle. Effect of nerves and hormones.
PHYSIOLOGY OF THE CENTRAL NERVOUS SYSTEM
UNIT № 1
Topic: Organization and mechanisms of the central nervous system activity.
The purpose of the unit: to understand structure and functions organization of CNS, reflex
principle of its activity.
Questions for Self-preparation
1. General design and major levels of the central nervous system. Physiological properties and
functions of neurons, neuron types.
2. Neuroglia. Types and functions of the cells.
3. Interneuron interactions. Synaptic organization of CNS, neurotransmitter substances.
4. Transmitters effect on the postsynaptic membrane. Chemical substances that act as direct
synaptic transmitters. “Second messenger” systems.
5. Electrical basis for neuronal excitation and inhibition.
6. Mechanism of inhibition process in СNS. Different forms of inhibition.
7. Neuronal pools. Transmission and processing of signals in these pools. “Excitatory state”.
“Facilitation” of neurons.
8. Reflex principle of the CNS activity, reflex arch. Classification of reflexes. Properties of
reflexes: one way conduction, summation, occlusion, etc.
5
Practice
1. Reflex Time Depends on the Strength of Stimulation (Turk’s Method).
Prepare a spinal frog by removing its brain (decapitation) and leaving its spinal cord intact. Fix
the obtained spinal preparation on the rack hook. Note that the experiment can not start
immediately, since the activity of the spinal cord is suppressed due to spinal shock. Place one
hind leg in 0.25% sulphuric acid solution. Determine the time interval between placing the leg
in the solution and the onset of response. Wash the leg with water. Repeat the experiment using
0.5% and 1% sulphuric acid solution. Explain difference in the results.
2. The Reflex Arch Analysis.
Make the spinal preparation of a frog and attach it on the rack hook. Impregnate the filer paper
with 0.5% sulphuric acid solution and place it to the skin of the leg. Wait for the onset of flexion
reflex. Separate the sciatic nerve on the dorsal femoral surface and tie it with a ligature. Place
the impregnated filter paper once more. Wait for response. Then remove a skin flap from the
other leg, stimulate this leg with acid. Wait for response. Destroy the spinal cord by inserting
the probe into the spinal canal. Repeat stimulation of the fore leg. Give you explanation for
absence of motor response. Draw down the scheme for somatic reflex arch in the notebook.
3. Sechenov’s Inhibition Experiment.
Take the frog and open its skull. Cut the brain above the thalamus. Suspend the thalamic frog on
a hook by a lower jaw. In few minutes simulate one of the hind limbs with 0.5% sulphuric acid
solution. Take the time of Turk’s reflex. Then put one crystal of sodium chloride on the brain
section. Take the time of Turk’s reflex in 5 minutes. Then wash the section of the brain from the
salt and take the reflex time in more 5 minutes. Make your conclusion.
4. Irradiation of Excitation in the Central Nervous System (Experiment with Strychnine).
Take the frog and inject 0,5 ml 1% strychnine solution in its lymphatic bag. Observe the frog’s
behavior for several minutes. Observe its convulsive reaction in response to weak touch. Pay
attention on improper position of the animal, on the inability of usual movements. Explain the
observed reactions. Bear in your mind that strychnine possesses the ability for temporal block of
inhibitor neurons in the central nervous system.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006. P. 341-355, 361-366.
6
UNIT № 2
Topic: Physiology of the brain structures, their role in the control of motor functions.
The purpose of the unit: to understand the role of the spinal cord and upper brain structures in
mechanisms of muscular tone regulation.
Questions for Self-preparation
1. Organisation and reflex activity of the spinal cord. Spinal shock.
2. Muscle stretch reflex. Clinical application of the stretch reflex. Gamma-efferent system.
3. Reflex activity of brain stem. Vitaly important reflexes. Reticular, vestibular and red nuclei
systems in supporting the body against gravity. The decerebrate animal.
4. Physiology of cerebellum. Functions of various cerebellum departments. Neuronal circuit of
the cerebellum. Functional unit of the cerebellar cortex. Clinical abnormalities.
5. Thalamus as a collector of afferent pathways, its role in the integrative brain activity.
Functions of thalamic nuclei.
6. Basal ganglia – their motor functions. Functions of the specific neurotransmitter substances
in the basal ganglia system.
7. Organization of the cerebral cortex. Somatosensory cortex. Motor areas. Association areas.
8. Reflexes of posture and locomotion (Table 1).
Practice
1. Spinal Shock Phenomenon (Experiment in a Frog).
Prepare a spinal frog by removing its brain (decapitation) and leaving its spinal cord intact. Fix the
obtained spinal preparation on the rack hook. Try to obtain flexor reflex. Explain absence of any
reflex reaction.
2. Deep Reflexes or Tendon Jerks.
Biceps reflex. Tap the tendon of the biceps with a percussion hammer. The response is flexion of
the elbow. Centre is C5-6 segments.
Triceps reflex. Tap the tendon of triceps when the elbow is slightly flexed. The response is
extension of the elbow. Centre is C6-7 segments.
Ankle jerk (Achilles tendon jerk). Tap the patient’s Achilles tendon with the percussion hammer.
The response is flexion and extension of the foot. Centre is S1-2 segments.
Knee jerk. Ask the patient to sit down and put one his leg to another. Tap the patellar tendon with a
percussion hammer. The response is extension of the knee. Centre is L3-4 segments.
7
3. Cerebellar Tests.

Romberg pose (static): put foots together, close eyes, extend hands and move fingers apart.
Keep this position.

“Finger – nose test”: touch your nose by index finger of left and right arms first with the
open eyes and then blindly.

Revealing of dismetry symptom: blindly in the Romberg pose put one hand down and then
lift it up to the level of the other hand.

Revealing adiadokhocinesis symptom: move quickly brushes of the extended hands; such
movements will be asynchronous in case of cerebellum defeat.
3. Posture Reflexes, Experiment in Guinea -Pig.
Take a healthy animal. Observe its normal position. Check the position of paws during moving the
head downwards and upwards. Try to put the animal on its side. Try to hold its head in the lateral
position. Mark change in the muscular tone at lifting animal upwards and putting it downwards.
Switch off one of animal’s labyrinths by dropping some chloroform into its ear and keep the animal
in this position for some minutes. Observe any changes in the position of the animal. Observe state
of muscle tone, nystagmus and circular movements. Test cervical and labyrinth postural reflexes.
Pay attention on the eye movements at violent fixation of the head in normal position.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 445-455, 463-464, 470-488.
Table 1
I. Static Reflexes at a Change of the Position of the Body, Not Connected With Moving
Reflexes of a pose
Straitening reflexes
Appear
While changing of the head position in relation While disturbance of the normal pose
to the trunk position in space
From receptors of From receptors of From
From
From
labyrinths
sinews and muscle’s receptors of receptors of receptors of
receptors of neck
labyrinths
skin and mus- retina of eyes
cles of neck
and trunk
Are directed to
Preservation of the normal pose at threat of its Restoration of the normal pose in case of its
disturbance
disturbance
Are expressed in
Redistribution of a muscular tone of extensors, Consecutive restoration of normal position of a
preventing infringement of balance
head and a trunk in space
8
II. Stato-Kinetic Reflexes at Strait and Rotary Movement with Acceleration
Reflexes at rotation of a body (compass ones) Reflexes at linear vertical movement (lift ones)
Appear
From receptors of labyrinths, muscle’s From receptors of labyrinths of semi lunar
receptors, receptors of retina of eyes
channels
Are directed to
Preservation of the body position in space at Preservation of the body position in space in the
rotary movement
case of ascent, descent and at landing
Are expressed in
Change of a tone of muscles of the head and At ascent - in bending and the subsequent
eyes (nystagmus), trunk, extremities
straitening of head, trunk and extremities; at
descent - in return sequence of the same
reactions; at a landing - extremities accept the
position being capable of holding balance while
meeting with the ground
UNIT № 3
Topic: Nerve regulation of inner organs functions; methods to study the central nervous system.
The purpose of the unit: to understand organization and functions of the autonomic nervous
system; to study modern electro-physiological methods of central nervous system research.
Questions for Self-preparation
1. General organization of the autonomic (vegetative) nervous system.
2. Physiological anatomy and basic characteristics of the sympathetic nervous system.
3. Physiological anatomy and basic characteristics of the parasympathetic nervous system.
4. Effects of sympathetic and parasympathetic stimulation on different organs.
5. Mass stimulation and localized responses caused by sympathetic and parasympathetic
nerves.
6. Higher brain areas control of the autonomic nervous system from. Hypothalamus - the
supreme integrative centre of the somatic, autonomic and endocrine functions.
7. Autonomic reflexes. Peculiarities of the autonomic reflex arch.
8. Modern methods of CNS research (electroencephalography, method of the caused
potentials, microelectrode technique, stereotaksis technique).
Practice
1. The Cool Test.
Take person’s pulse rate and blood pressure. Then put his hand in cold water (40С) for 1 minute.
Take blood pressure and pulse rate once more and then do it every minute until the parameters turn
to initial level (usually in 2-3 minutes). Reaction is estimated as strong sympathetic if blood
9
pressure increases more than 20 mm Hg, as moderately sympathetic - less than 10 mm Hg, as
parasympathetic - at pressure decline. Put the results in the table and make conclusion.
Blood pressure
Parameters
Systolic
Pulse rate
Diastolic
Control values
After cold application
1 min
2 min
2. Behaviour and Autonomic Reactions of a Rabbit under Electric Stimulation of Brain
Structures.
3. Study of Basal Autonomic Tone by Kerdo Autonomic Index.
Take patiant’s blood pressure and pulse rate in sitting position. Calculate the Kerdo autonomic
index (KAI) using parameters of diastolic blood pressure (DBP) and pulse rate (PR): KAI = (1DBP/PR) * 100%. Make a conclusion about autonomic basal tone according to the following
classification.
Normal tone: KAI +10% till 10%.
Sympathetic prevalence in autonomic balance: KAI over + 10%.
Parasympathetic prevalence in autonomic balance: KAI lesser than 10%.
4. Electroencephalogrphy.
The EEG is recorded either with bipolar arrangement (two recording electrodes placed on the
scalp) or with unipolar arrangement (recording electrode is on the scalp and distant reference
electrode on the earlobe). The graph is interpreted primarily on the base of frequency,
amplitude, shape and pattern of the EEG waves. Use the sample of EEG. Try to analyze the
EEG, think about the types of the EEG waves. Compare the data obtained by analysis of EEG in
patient’s resting state with closed eyes and under stimulation
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 503-505, 511-512, 517-527.
Questions for Colloquium
1. Organization and major levels of CN. Physiological properties and function of neurons.
Neuron types. Neuroglia.
10
2. CNS synapses. Classification of synapses. Characteristics of electrical and chemical
synapses. Synaptic organisation of CNS.
3. Classification of neurotransmitters. Chemical substances that function as synaptic
transmitters.
4. Action of the transmitters on the receptor proteins of postsynaptic membrane.
5. Electrical events during neuronal excitation and inhibition.
6. Different forms of inhibition in the CNS.
7. Transmission and processing of signals in neuronal pools: divergence, convergence,
afterdischarge, “dominant” principle.
8. Reflex principle of CNS activity. Classification of reflexes. Sensory, central and motor part
of reflex arch.
9. Properties of reflexes: one way conduction, summation, occlusion, recruitment, subliminal
fringe, afterdischarge, fatigue.
10. Organisation of the spinal cord for motor functions. Autonomic reflexes of the spinal cord.
Spinal cord transaction and spinal shock.
11. Muscle stretch reflex. Receptor functions of the muscle spindle. Clinical application of the
stretch reflex.
12. Flexor and crossed extensor reflex. Reciprocal innervations and reciprocal inhibition.
13. Role of the brain stem in the control of motor function. Reflexes of posture and locomotion.
14. Cerebellum and its motor functions. Function of the cerebellum in overall motor control.
15. Thalamus as an afferent pathways collector, its role in the integrative brain activity.
Functions of thalami nuclei.
16. Hypothalamus- the supreme centre of vegetative and endocrine control of an organism
functions.
17. Motor functions of basal ganglia. Functions of specific neurotransmitter substances in the
basal ganglia system.
18. Cerebral cortex, characteristic of specific cortical areas. Somatocensory cortex.
19. Electrical activity in the brain. Brain waves. Electroencephalography.
20. General organization of the autonomic nervous system. Neurons of sympathetic and
parasympathetic nervous system.
21. Basic characteristics of sympathetic and parasympathetic function. Sympathetic and
parasympathetic “tone”.
22. Excitatory and inhibitory effects of sympathetic and parasympathetic stimulation on
different organs.
23. Autonomic reflexes. Control of brain stem autonomic centres by higher areas.
11
PHYSIOLOGY OF ENDOCRINE GLANDS
The purpose of the unit is to study mechanism of hormone action, to discuss functions of specific
endocrine glands and effects of their hormones.
Report Topics
1. Types of chemical messenger systems in organism. Endocrine system.
2. Chemical structure and synthesis of hormones. Stages of hormone “life”.
3. Mechanisms of hormone action. Main features of hormones.
4. Methods to study endocrine functions.
5. Pituitary gland and its relation to the hypothalamus. Posterior pituitary gland.
6. Anterior pituitary gland. Functions of growth hormone.
7. Thyroid metabolic hormones, their physiological functions.
8. Adrenocortical hormones. Functions of mineralocorticoids. Effects of aldosterone.
9. Adrenocortical hormones. Functions of glucocorticoids.
10. Endocrine part of the pancreas. Metabolic effects of insulin. Glucagons and its functions.
11. Calcium and phosphate regulation in the extracellular fluid and plasma. Parathyroid
hormone. Calcitonin.
12. Male sex hormones. Functions of testosterone.
13. Female sex hormones, ovarian hormones. Effects of estrogen on specific organs.
14. Hormonal function in pregnancy.
15. Control of male and female sex hormones by hypothalamic pituitary hormones.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 74, 612-715.
PHYSIOLOGY OF ANALYZERS
UNIT № 1
Topic: Physiology of sensory systems. Visual analyzer. Chemical senses, taste and smell.
Purpose of the unit: to study sensory systems and the basic principles of their function.
Questions for Self-preparation
1.
Characteristics of sensory receptors: Types of sensory receptors and stimuli. Modality of
sensation – the “Labeled line” principle.
12
2.
Conversion of sensory stimuli into nerve impulses: local potentials of nerve endings - receptor
potentials; mechanisms of receptor potentials.
3.
Optics of the eye. Mechanism of refraction. Errors of refraction.
4.
Mechanism of "accommodation".
5.
Visual acuity. Binocular and monocular vision.
6.
Function of the retina. Photochemistry of vision. Rhodopsin-retinal visual cycle and excitation
of the rods.
7.
Color vision. Photochemistry of color vision. Color blindness.
8.
Visual Pathways. Organization and function of the visual cortex. Fields of vision; perimetry.
Practice
1.
Weber’s Experiment.
The Person holds a weight of 100 grams in his hand. Then, Observer adds a weight of 300
mg, 500 mg, etc…on the Person’s hand. The Person has to inform when he feels that the mass in his
hand becomes heavier. Repeat this experiment starting with 50 gms weight. Make a conclusion –
sensation is related to the stimulus strength.
2.
Visual Acuity Test.
Patient stays 5 meters far from the table and closes one eye by special dashboard. Observer
shows letters (rings) in the different lines of the chart; the Patient repeats letters (or where is the gap
in the ring). Visual acuity is calculated by Snellen’s formula: V=d/D, where V - visual acuity, d - a
distance from eye to the cart, D - normal distance.
3.
Visual Field Test.
The Person puts his head on the plane of Forster’s perimeter and closes one eye. The
Person looks into the centre of the perimeter, not moving the eye. Observer takes the pointer with
color marker and moves it along the perimeter arch to its centre. The Person says, when he observes
the marker. Repeat this experiment turning arch of perimeter in 15º, 30º, 60º and 90º. Make a
conclusion.
4.
Detection of the Retina Blind Spot.
Person takes the card with symbols “+” and “O”. The Person closes his left eye and looks
at the “+” symbol moving the card slowly. Symbol “O” disappears at the 20-25 cm distance. Repeat
this experiment with the other eye. Make a conclusion.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 356-358, 392-426.
13
UNIT № 2
Topic: Special senses: Hearing, vestibular, taste and smell.
The Purpose of the unit: to study the main mechanisms of sound perception, chemical sensation.
Questions for Self-preparation:
1.
The sense of hearing. Conduction of sound wave from the tympanic membrane to the cochlea.
2.
Inner ear. Determination of the sound frequency: the "Place" principle, "Traveling wave".
3.
Auditory pathways. Central auditory mechanisms.
4.
Vestibular sensations and maintenance of equilibrium.
5.
Sense of taste. Primary taste sensation. Threshold for taste.
6.
Sense of smell. Primary smell sensation. Threshold for smell. Mechanism of the olfactory
cells excitation.
Practice
1.
Hearing Acuity Test.
Person closes one ear and turns sideways to prevent reading from the lips. Observer reads
slowly and not loudly the words with the bass sound. If Person can not repeat words he comes
closer to Observer. The chart contains 3 groups of words for 5, 12 and 20 m distance to determine
hearing acuity.
2.
Spatial Sound Localization.
Set into both ears of Person a long rubber tube. Observer makes a sound by tapping right
side, left side and centre of the tube. Person must detect location of the sound. Then Observer
compresses the tube and taps near the place of the compression. Person must detect the place of the
sound again. Make a conclusion about the factors making possible proper spatial localization of the
sound.
3.
Deafness Simulation Test.
Person reads the text. Mark the loudness of his reading. Person puts on the earphones and
Observer switches on the source of sound. Pay attention that Person begins to read louder. If the
Person is deaf he can not do it.
4.
Olfactometry.
The Person puts olives of olfactometer in both nostrils. Vapors of smelling substance are
introduced by means of the syringe into nose until Person can name the Smell (measured in cm3).
5.
Taste Threshold.
Observer puts on the Patient’s tongue a drop of one of the following solutions: sweet, acid,
salty, bitter (the concentrations of the solutions 0,001%, 0,01%, 0,1%, 1%). Experiment starts with
14
the minimal concentration, then concentration is increased till Person is able to define the taste of
the proposed solution.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 427-444, 464-468.
UNIT № 3
Topic: The sense of pain. Somatic sensation, thermal sensation
The Purpose of the unit: to study of the basic mechanisms of skin sensations, get acquainted with
manifestation and mechanisms of pain.
Questions for Self-preparation:
1.
Somatic sensations: general organization. Classification of somatic senses. Tactile receptors.
Two point touch threshold. Adaptation of receptors.
2.
Thermal sensations. Thermal receptors and mechanism of their excitation.
3.
Pain. Types of pain: fast pain and slow pain, referred pain. Pain receptors and their
stimulation.
4.
Dual pathways for transmission of pain signals into the central nervous system.
5.
Pain suppression ("Analgetic") system in the brain and spinal cord.
6.
Physiological base for anesthesia/
Practice
.1.
Aristotle’s Experiment.
Person closes eyes, turns his middle finger over the second finger. Observer puts the small
boll between Person’s fingers. Person describes what he feels. Make a conclusion explaning role of
the cortex in sensation.
2.
Two-Point Touch Threshold in the Different Skin Areas.
Person closes his eyes. The Observer touches different areas of the skin by the Veber’s
compass with restricted drumstick (finger-tips, palm, forearm, shoulder, back), with both the
drumsticks simultaneously. Touch with a minimum distance of 1 mm each time until the Person
feels double touch.
3.
Thermoesteziometria.
Put the ice into thermoesteziometer glass and find cold receptors in 1 sm2 areas of skin (the
finger, palm, forearm, shoulder, neck, back, face). Put hot water into thermoestesiometer glass and
find heat receptors the same way.
15
4.
Types of Pain Sensations.
Prick yourself with the needle. Pull your hair initially in a short time period and then after
long time gap. Compare your sensations when you squeeze: 1) the skin between two fingers or 2)
the tendon. Make a conclusion about types of pain.
5.
Pain Receptors Topography.
Draw a 1 sm2 square on dorsal surface of your hand. Prick each point of square with the
needle. Distinguish two sensations: touch feeling (the tactile receptor) or unpleasant feeling with a
sense of burning (the pain receptor). Make a scheme of pain receptors.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 359-360, 367-369, 371-373,
379-386, 388-390.
Questions for Colloquium
1.
Sensory receptors: classification of sensory receptors. Modality of senses.
2.
Convertion of sensory stimuli into nerve impulses. Mechanisms of receptor potentials.
Adaptation of receptors.
3.
Somatic sensations: general organization. Classification of somatic senses. Detection and
transmission of tactile sensation. Two point touch threshold.
4.
Thermal sensations.
5.
Sense of taste.
6.
Sense of smell.
7.
Pain. Pain receptors and their stimulation. Transmission of pain signals into the central
nervous system.
8.
Pain suppression ("Analgesia").
9.
Referred pain. Visceral pain.
10.
The sense of hearing. Transmission of sound.
11.
Transmission of sound waves in the cochlea -"Traveling Wave". Determination of sound
frequency-the "Place" principle.
12.
Determination of loudness. Central auditory mechanisms.
13.
Vestibular sensations and maintenance of equilibrium.
14.
Organization and function of the visual analyzer. Intraocular fluid. Intraocular pressure.
15.
Mechanism of refraction. Errors of refraction.
16.
Mechanism of "Accommodation".
16
17.
Visual acuity. Determination of distance of an object from the eye. Binocular and monocular
vision.
18.
Function of the structural elements of the retina. Fields of vision.
19.
Photochemistry of vision. Dark and light adaptation.
20.
Color vision. Photochemistry of color vision. Color blindness.
INTEGRATIVE AND INTELLECTUAL FUNCTIONS OF THE BRAIN
UNIT № 1
Topic: Physiological basis of conditioned reflexes and learning.
The purpose of the unit: to study mechanisms and characteristics of conditioned reflex.
Questions for Self-preparation
1. Learning. Classification of conditioned and unconditioned reflexes by Pavlov.
2. Characteristics and functions of conditioned reflexes, their importance.
3. Working out conditioned reflex, procedure.
4. Conditioning, temporary connection in the cortex is the base for conditioned reflex.
5. Inhibition during learning, different types of inhibition.
6. Function of the brain in speech and communication. Sensory and motor aspects of
communication.
Practice
1. Working out Conditioned Blinking Reflex in Students.
The conditioned blinking reflex is based on defensive unconditioned reflex in response to air flow
to the cornea. First observe the unconditioned blinking reflex: blow air to the eye by means of
rubber pear (choose the force of air flow which causes blinking). Use light of a red lamp as
indifferent stimulus and combine it with air flow to the eye (light first and air flow in 1-5 seconds).
You may work out conditioned blinking reflex after 5 or 6 light/air combinations. Observe the
conditioned reaction fast blinking or in closing the eyes in absence of the air flow. Make the scheme
of the reflex arch in your copy-book.
2. Working out Conditioned Word-based Reflex.
Conditioned word-based reflex has its central part in nerve centers of the second signal system. The
base of the reflex is the accurate verbal instruction: "Press the rubber pear as soon as red lamp is
17
switched on, do not compress the pear if lamp is green". In this case green light of the lamp is a
neutral signal. You may work out the conditioned word-based reflex after several combinations (78) of the light and verbal instruction. The conditioned reaction manifests in pressing the rubber pear
after switching on the red light without verbal instruction. Compare the reflex time of blinking and
word-based conditioned reflexes, txplain the difference.
3. The Corrective Test.
This experiment is carried out by all the students. Student has special chart with letters for four
tasks, 3 minutes for each task. Wright down all 4 results.
Task 1. Count a certain letter in all lines of the chart. If student counts the letter correctly (possible
mistake is + 2 units) it means balance of his excitation and inhibition processes; if the result is
wrong - the process of inhibition prevails; if the task is done correctly and promptly (less then 2,5
minutes) - the process of excitation prevails.
Task 2. Count the same letter in the situation of external inhibition (loud reading). If the task is
done correctly - the process of excitation prevails; if the result is wrong – the process of inhibition
prevails; if the result is better than in Task 1 (more exactly or faster) - balance of excitation and
inhibition is observed.
Task 3. Count the definite set of letters. The exact result (+ 5%) indicates proper discriminative
ability.
Task 4. Repeat Task 1 and compare results. More number of mistakes or more taken time point on
the fatigue process in the brain. Batter result means increased working capacity.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P. 488-493.
UNIT № 2
Topic: Neurophysiology of memory. Behavioral functions of the brain and emotions. Theories of
sleep.
The purpose of the unit: to study mechanisms of emotions, memory and sleep.
Questions for Self-preparation
1. Types of the higher nervous activity (by Hippocratus, by Pavlov).
2. Memory. Classification of memory. Mechanisms of short-term and long-term memory. Role
of the brain in the memory process.
18
3. Sleep. Types of sleep. Basic theories of sleep. Sleep and wakefulness cycle.
4. Brain waves, EEG characteristics of different stages of sleep.
5. Behavioral and motivational mechanisms of the brain, role of limbic system and the
hypothalamus.
Practice
1. Level of Short-Term Memory.
The Observer reads slowly a set of any 10 words. Students reproduce the set in the same order in
copy-books. The experiment is repeated three times with different sets of words.
Define percentage of memorized words first for each set:
K1 = a / 10 х 100, where a- amount of remembered words. Then calculate the average volume of
the short-term memory:
K = (K1+K2+K3) / 3.
The result is excellent if K = 91-100; very good - K = 71-90; good - K = 51-70; satisfactory - K =
31-50; bad - K = 11-30 and very bad - K = 0-10.
2. Eysenk’s test.
Answer all the questions of Trait 1 and Trait 2 and then analyze the result according to the key.
Literature:
Guyton A.C., Hall J.E.: Textbook of Medical Physiology. 11/e, 2006.P.343, 493-513.
Questions for Colloquium
1. Learning. Classification of conditioned and unconditioned reflexes by Pavlov.
2. Characteristics and functions of conditioned reflexes, their importance.
3. Working out conditioned reflex, procedure.
4. Conditioning, temporary connection in the cortex is the base for conditioned reflex.
5. Inhibition during learning, different types of inhibition.
6. Function of the brain in speech and communication. Language input, sensory aspects of
communication.
7. Function of the brain in speech and communication. Language output, motor aspects of
communication.
8. Memory. Classification of memory.
9. Synaptic facilitation and synaptic inhibition, role in memory storage.
10. Short-term memory, neuron base.
19
11. Intermediate long-term memory, molecular mechanism.
12. Long term memory, consolidation of memory.
13. Activating-driving system of the brain.
14. The limbic system of the brain.
15. Vegetative and endocrine control functions of the hypothalamus.
16. Behavioral functions of the hypothalamus.
17. Reward and punishment centers, importance in behavior.
18. Types of the higher nervous activity (by Hippocratus, by Pavlov).
19. Sleep, two types of sleep.
20. Basic theories of sleep.
20