This document outlines the plan and content for a lecture on nerve-muscle physiology. The lecture will cover: 1) nerve physiology including classification of neurons and nerve fibers, 2) adaptive responses of the body to stimuli, 3) arousal and excitability of tissues, 4) irritating and irritant factors, 5) excitable tissues including nerve, muscle and gland tissues, 6) the synapse, and 7) muscle tissue including types and functions. It will also discuss topics such as parabiosis, action potentials, ion pumps and channels, and the physiological properties of muscle tissue including excitability, conduction, contraction, elasticity and automatism.

1. Plan of lecture
1. Nerve-muscle physiology
2. Adaptive response of the body
3. Arousal and excitability
4. Irritating and irritants
5. Excitable tissues
6. Nervous tissue
7. Classification of neurons
8. Nerve fibers
9. Parabiosis
10. The synapse
11. Muscle tissue
12. Functions of muscle tissues
13. Membrane potential
14. Action potential
15. Bioelectric phenomena
16. Cell membrane
17. Ion pumps
18. Ion channels
2nd week. Nerve-Muscle Physiology
Lecturer: Ablaykhanova N.T.
Assistant: Balmaganbet Zarina

2. Nerve-Muscle Physiology
Nerve:
 The filamentous bands of nervous tissue that connect parts of the nervous
system with the other organs, conduct nerve impulses impulses, and are
made up of axons and dendrites together with protective and supportive
structures.
 All living cells and tissues are able to perceive certain effects and, in
response, change the level of the metabolic process in themselves, which
changes their corresponding functional state. This is called irritation.
 Irritation is the result or manifestation of irritability. As a Friedrich Engels
said, irritability is a common property inherent in all living matter.
 The physiology of arousal studies the general patterns of interaction
between living structures and factors affecting them. In this regard, he
calls the structures exciting structures. Usually such structures include
muscle, nerve and secretory cells and tissues. The factors of the external
and internal environment or the various forms of motion of matter that
affect them are called stimuli, and the effects themselves are called stimuli.

3. Adaptive response of the body
.
Irritation Excitability Arousal
Irritants:find the
threshold, above the
threshold and below the
threshold.
Tissue excitability is
characterized by the
threshold of action of the
stimulus – the minimum
amount of stimulus that
causes arousal.

4. Аrousal and excitability
• Arousal is a manifestation of a specific active reaction inherent only to
them, when the metabolic tendency in the cell and tissue reaches a
qualitatively new level as it grows, provided that the strength and duration
of the corresponding adequate stimulus are sufficient. Arousal is carried out
due to the property of excitability. In a cell, tissue, or organ that has lost
excitability, arousal does not occur. Therefore, excitability should be
understood as the main property reflecting the liveliness of living
structures. Through excitability, various cells, tissues, organs can be
compared with each other. In excitable structures, the external
manifestations of arousal differ. Thus, the excitation of meat manifests
itself in its contraction, the excitation in epithelial cells-in changes in their
electrical state.

5. Irritating and irritants
• All living cells and tissues are able to perceive certain effects and, in
response, change the level of the metabolic process in themselves, which
changes their corresponding functional state. This is called irritation.
• Irritation is the result or manifestation of irritability. As a Friedrich Engels
said, irritability is a common property inherent in all living matter. The
physiology of arousal studies the general patterns of interaction between
living structures and factors affecting them. In this regard, he calls the
structures exciting structures. Usually such structures include muscle, nerve
and secretory cells and tissues. The factors of the external and internal
environment or the various forms of motion of matter that affect them are
called stimuli, and the effects themselves are called stimuli.

6. Irritants by nature
physical
(temperature, air,
pressure, moisture,
sound, radiation,
electric current, etc.)
chemical (salts,
acids, alkalis, various
toxic substances,
etc.)
biological
(microorganisms,
other living objects)

7. PROPERTIES AND INDICATORS OF EXCITABLE TISSUES AND THEIR
CHARACTERISTICS
Property Indications
1. Excitability is the ability to excite. Threshold of irritation, rheobase, chronaxia,
absolute, duration of the refractive period,
speed of accommodation.
2. Conduction is the conduction of
excitation throughput.
The speed of conduction of the action
potential is 120 m/SEC on the nerve, or 600
km / h.
3. Contractility is the ability to develop
strength and energy during excitation.
The maximum indicator of the strength of
the power during excitation.
4. The labile nerve is the ability of the
functional mover to activate with a
certain rhythm.
The number of maximum excitability at a
certain time, for example, nerve 1 sec. Can
produce 1000 action potentials.
5. The ability to secrete (mediator). Size, volume of the particle, secret.

8. Excitable tissues
Muscle tissue
Nerve tissue
Glands

9. Nervous tissue nerve cell neuron
structure

10. Classification of neurons
A - multipolar; B - biopolar; B-pseudounipolar; G-unipolar;
1-dendrite, 2-Axon.

11. Nerve fibers
• The outgrowths of a nerve cell covered with a
membrane on the outside are called nerve
fibers.
Nerve fibers come in 2 types:
With myelin
Without
myelin

12. NERVE FIBER TYPES & FUNCTION

13. Patterns of conduction of excitation
• Conducting excitation without decrement.
• Physiological and anatomical integrity.
• Conducting excitation in two directions.
• Conducting excitation in isolation.
• Relative tirelessness of the nerve fiber.

14. Excitation distribution in nerve fibers:
A-myelin-free fiber, B-myelin fiber
direction of the excitation wave
Ranvier belt
Axon
Axon
Myelin

15. If there is no myelin of the nerve fiber, excitation
along it occurs continuously.The action potential
generated in one place generates the action potential
of the neighboring earth.
Nerve impulses cannot continuously pass through a
myelinated nerve fiber.In this case, nerve impulses
from one Ranvier belt to another bounce off, and the
movement of excitement accelerates.

16. The speed at which a nerve fiber conducts
excitation
Fiber type diameter of fibers
(mcm)
transmission speed
(m/s)
А
Аα
Аβ
Аγ
Аδ
В
С
12-22
8-12
4-8
1-4
1-3
0,5-1,0
70-120
40-70
15-40
5-15
3-14
0,5-2

17. Parabiosis is a special, long-term, undulating stable
form of excitation that arises in response to various
external influences.
1. after the nervous breakdown, the meat responds
to a stimulus of different strength and frequency
at the same level as the stage of its equalization;
2. the paradoxical stage is when a nerve responds to
a strong and frequent stimulus with a weak
contraction, and to a weak and rare stimulus with
a strong contraction on the contrary;
3. failure to respond to any stimulus is a stage of
inhibition.

18. • In 1901, N.E. Vvedensky
wrote his work "excitation,
inhibition and anesthesia",
revealing the classical
theory of parabiosis.
Н.Е.Введенский
N.E. Vvedensky

19. Neuromuscular Synapse Scheme:
1-myelinated nerve fiber: 2-nerve end with mediator vesicles; 3-presynaptic
membrane; 4-postsynaptic membrane of muscle fiber; 5-synaptic gap; 6-extra-
synaptic membrane of muscle fiber; 7 — myofibrils; 8-sarcoplasm; 9-action
potential of nerve fiber; 10-end plate potential; 11-action potential of muscle
fiber

20. Parabiosis and its stages
P A R A B I O Z (para – approx, bios – life) is
a decrease in its excitability and lability due to
the action of an irritant (chemical substance).
← Normal.
Stages of parabiosis:
1. alignment stage;
2. The Paradoxical stage;
3. The deceleration period.
In the period of complete parabiosis, i.e. in
the area of irritation, the tendency to spread
excitation stabilizes in one place without
spreading ("stationary excitation").
20 Hz 30 Hz 50 Hz

21. The synapse
 A synapse is a structural extension that transmits excitation (or impulse) from
nerve fibers to a muscle or nerve cell.
 Synapse structure: consists of the presynaptic nerve end, the synaptic cleft
between the nerve end and the effector cell, and the postsynaptic
membrane.Between the presynaptic and postsynaptic membranes, the synapse
gap is an intercellular fluid-filled space.An important feature of the postsynaptic
membrane is that the receptors located here are capable of biochemical
interaction only with the corresponding types of mediators.

22. Types of synapse
I. depending on the transmission of signals:
- chemical synapse;
- electrical Synapse;
- mixed Synapse.
II. depending on the impact:
- instigator;
- brake.
III. depending on the location:
- nerve-meat (myoneural);
- neuroneuronal:
1) axosomal;
2) axoaxonal;
3) axodendritic;
4) arboreal, etc.

23. 1. Muscle tissue
Types of muscle tissue:
1. Striated skeletal muscle;
2. Striated heart muscle;
3. Single-branch muscles.
Functions of striated muscles:
1) movement (dynamic and static);
2) provision of respiration;
3) mimic;
4) receptor;
5) collective;
6) temperature controller.
Functions of the muscles of a Single industry:
1) pressure stability in hollow organs;
2) regulates the pressure in the blood vessels.
The heart muscle-blood performs a function that ensures the movement of
blood through the vessels.

24.  Muscle is a soft tissue.
 Muscle cells contain protein filaments of actin and myosin.
Types of Muscle:
a. Skeletal Muscle;
b. Smooth Muscle; Muscle; and
c. Cardiac Muscle.
MUSCLE TISSUE

25. • 1) Movement (dynamic and static);
• 2) Providing breathing;
• 3) Facial expressions;
• 4) Receptor;
• 5) Collector;
• 6) Temperature controller.
Functions of
the transverse
striated
muscles
•1) Pressure stability in cavity organs;
•2) Blood regulates the pressure in the vessels.
Functions of
single-branch
muscles
• The blood has a function that ensures the movement of
blood through the vessels.
Heart muscle
function

26. Physiological properties of muscle
1. excitability-the excited reaction of the muscles to the stimulus.;
2. conduction-the passage of excitation through the muscle;
3. contraction is a change in length or tension during arousal.;
4. elastic (elastic, flexor) - the return of the muscle to its original
shape after contraction;
5. automatism is when we mean the excitation of tissue by
impulses that occur inside it without causing irritation from the
outside.
6. plasticity is the preservation of a shape with a modified length
for a while.

27. SKELETAL MUSCLE STRUCTURE

28. STIMULATION AND CONTRACTION OF
SKELETAL MUSCLE
 Excitability - ability to receive and respond to stimulus;
 Contractility ‐ ability to shorten when adequate stimulus is received;
 Extensibility ‐ ability of muscle to be stretched;
 Elasticity‐ ability to recoil and resume resting length after stretching.

29. The mechanism by which muscles contract is very complex,
so several theories have been proposed to explain it
Actomyosin theory. In 1939, V. A.Engelgardt and M. N. Lyubimova found
that the myosin protein is characterized by the properties of the ATP-Aza
fermetum, which breaks down ATP, therefore, under the influence of ATP, the
myosin filaments are shortened and the muscle contracts.
Hungarian scientist A.Scent-Gyordi discovered that the muscle fiber
contains a second protein — actin.
Currently, based on the actomyosin theory, A.The theory of protofibrils
sliding proposed by Hodgkin is accepted.

30. Types of muscle contractions I. meat reduction
depends on the specific condition (dependence) :
isometric mode
isotonic mode
auxotonic mode

31. Single muscle contraction (SMC)
SMC-occurs as a result of an
individual impulse effect.
1. latent (latent) period-0.01
sec;
2. the contraction period is
0.05 sec;
3.The relaxation period is 0.05
– 0.06 sec.
Time, 0,01 sec

32. Tetanus is when the muscles often respond to a stimulus by
contracting longer and stronger.
I. toothed tetanus occurs when
exposed to a low-frequency
stimulus (10 – 20 Hz).
II. flat tetanus occurs when
exposed to a high-frequency
stimulus (↑ 20 Hz).
Toothed tetanus
Flat tetanus Time, 0,5 s

33. The structure of the sarcomere

34. Its transverse vesicles with myosin filaments

35. Actin filaments

36. Muscle contraction mechanism

37. (a) Neuron at rest. Both Na+ and K+ channels are closed. (b) Na+ channels open and Na+ flows
into the neuron depolarizing the plasma membrane to +30mV. (c) Na+ channels close. K+
channels open and K+ flows out of the neuron repolarizing the plasma membrane to −70mV. (d)
K+ channels close and Na+ /K+ pumps reestablish resting ion distribution.
Depolarization and repolarization of a neuron

38. Cell membrane

39. Ion pump
• The ion pump is an integral protein that covers
the entire membrane. It provides anti-gradient
transport of ions.
• The sodium potassium pump is
a protein structure that is
included in a wide set of
molecules in many cell
membranes and responsible
for the active transport of ions
or other small molecules
against concentration
gradients.

40. • Ion channels are integral proteins that provide
passive transport of ions along the gradient.
Types of channels:
• Unmanaged or independent
• Potential is dependent
• Ligand dependent

41. •Membrane Potential
•Nerve Impulse Formation
•Repolarization
•https://www.youtube.com/watch?v=rcacx09VODc

42. Bioelectric phenomena
• Electrical changes in living structures are
called bioelectric phenomena.
Types of biopotential
• silence (membrane)
• damage (alternation)
• electroniclocal (non-spreading)gate,
• action (single-phase and two-phase)
• threshold potentials.

43. Membrane potential
The membrane potential is the potential difference between the
surface of the cell membrane and its protoplasm.The outer
surface of the membrane is charged "+" ;
The inner surface of the membrane is charged" -".
Muscle fiber membrane potential size:– 60 - – 90 MV.
Membrane
resting potential

44. RESTING MEMBRANE POTENTIAL
 Resting Membrane Potential
(RMP) is the voltage (charge)
difference across the cell
membrane when the cell is at
rest.
 RMP is a product of the RMP is
a product of the distribution of
charged particles (ions).
 There are positively charged
ions called cations ( N ions
called cations (e.g., Na+, K+,
Mg2+, Ca2+) and negatively
charged ions called anions (e.g.,
Cl- called anions (e.g., Cl and
proteins that act as anions).

46.  Step 1: Resting membrane potential.
 Step 2: Some of the voltage voltage‐gated Na‐channels channels
open and Na enters the cell (threshold potential).
 Step 3: Opening of more voltage‐gated Na‐channels and further
depolarization (rapid upstroke).
 Step 4: Reaches to peak level.
 Step 5: Direction of electrical gradient for Na is reversed +
Na‐channels rapidly enter a closed state “inactivated state” +
voltage – gated K‐channels open (start of repolarization).
 Step 6: Slow return of K‐channels to the closed state (after‐
hyperpolarization).
 Step 7: Return to the resting membrane potential.
ACTION POTENTIAL

47. Decreasing the external Na concentration has little effect on RMP, but reduces
the size of action potential.
Hyperkalemia : neuron becomes more excitable.
Hypokalemia: neuron becomes hyperpolarized.
Hypocalsemia: increases the excitability of the nerve.
Hypercalsemia: decreases the excitability.
ACTION POTENTIAL
Once threshold intensity is reached, a full action potential is produced.
 The action potential fails to occur if the stimulus is sub threshold in
magnitude.
 Further increases in the intensity of the stimulus produce no other
changes in the action potential.
 So, the action potential is all or none in character.

48. Absolute refractory
period: From the time
the threshold potential
is reached until
repolarization is about
one‐third complete.
Relative refractory
period: From the end
of absolute refractory
period to the start of
after–depolarization.
ACTION POTENTIAL

49. FLOW OF ACTION POTENTIAL

50. CONDUCTION of the ACTION
POTENTIAL

54. CONDUCTION of the ACTION
POTENTIAL
Myelinated axon:
 Myelin is an effective
insulator.
 Depolarization travels
from one node of Ranvier
to the next.
 This jumping jumping of
depolarization from node
to node is called
“saltatory conduction”.
 Faster than unmyelinated
axons.

55.  It shows the interdependence between stimulus strength and the time
required in activating the muscles.
 It indicates the strength of impulses of various durations durations
required required to produce produce muscle contraction contraction
by joining the points that graphically represent the threshold value
along the ordinate for various durations.
STRENGTH DURATION CURVE
 SDC test can be done 10 – 14 days after the lesion has occurred.
 The degeneration of nerve from the proximal to distal is called
Wallerian degeneration.
 When the motor end plate is no longer functioning functioning, it is
done weekly under the same condition until there is recovery and
decision has been reached on the eventual final state of the muscle.
 SDC is used to identify denervation, partial innervation, and
compression
Optimum timing of SDC:

56. Dimensions of
excitability
1-rheobase;
2-two rheobases.
a-useful time;
B-chronaxia.
1.Arousal threshold – refers to the minimum
amount of force of the stimulus causing the exciting
process (i.e. the minimum response).
2.Rheobase – the minimum current causing
excitation (Volts).
3.Useful time is the minimum time that causes
arousal when the threshold is exposed to force.
4. Chronaxia is the shortest duration of the force,
equal to two rheobases stimulating the tissue.
5. Accommodation – adaptation of excitable tissue
to the acceleration of the current. The force is
measured with a minimum acceleration time.
6. labile – indicates the maximum (maximum)
amount of arousal that occurs within one second in
accordance with the frequency of irritation.
- nerve tissue: - 500-1000 imp/sec;
- absolute refractory period-1-2 msec.
- muscles: - 250-330 imp/ sec;
- аbsolute refractory period-4-5 msec
- synapse: - 100-125 imp / sec; -
- absolute refractory period-8-10 msec.
The force–time curve (Gorweg, 1892;
Weiss, 1901; Lapik, 1909)
The force–time
curve
current
voltage,
V
Time, ms

57. Stages of change in excitability during arousal
1.absolute refractor stage. At this stage, the
tissue does not respond to any stimuli.
Duration of this period:
- in the nerve fiber-1-2 msec;
- in muscle-4-5 msec;
- in the myoneural Synapse-8-10 msec.
2.relative refractor stage. At this stage, a
response response to a stimulus above the
threshold force is born.
3.Supernormal stage. At this stage, the tissue
will respond in a puppy below the threshold.
4.subnormal stage. At this stage, the
excitability property of the tissue decreases
sharply and responds to a stimulus higher than
the threshold force.

58. Factors affecting Rehobase &
Chronaxie