Muscle physiology by S3

1. Muscle Physiology By S3 B.N.Y.S(2nd Year) S-VYASA University

2. Contents… Introduction Functions of muscle tissue Properties of muscle tissue Types of muscles Agonist and antagonist Anatomy of skeletal muscle Neuromuscular junction Sliding Filament Mechanism of Muscle Contraction Tone of the Muscle Stretch Reflex Golgi Tendon Questions Bibliography

3. Latin- Musculus (Mouse) Muscle is a contractile tissue It contains contractile filaments that move past each other and change the size of the cell Introduction…

4. Movement Stability Thermogenesis Body movement Respiration Constriction of organs and vessels Heart beat Functions of Muscle Tissue

5. Excitability capable of response to chemical signals, stretch or other signals & responding with electrical changes across the plasma membrane Conductivity local electrical change triggers a wave of excitation that travels along the muscle fiber Contractility -- shortens when stimulated Extensibility -- capable of being stretched Elasticity -- returns to its original resting length after being stretched Properties of Muscle tissue

6. Types of muscles

7. Agonist Antagonist Classification of skeletal muscle

8. Moves a body segment in the intended direction causes a movement Agonist

9. Muscle opposing the agonists, acts in the opposite direction Antagonist

11. Anatomy of skeletal muscle

14. Actin

15. Myosin

16. Neuromuscular Junction

18. Sliding Filament Mechanism of Muscle Contraction

28. mu

29. Tone of the Muscle

30. Natural firmness of muscles when they are not flexed Tightness of a muscle Some fibers are always contracted Hypertonia Atonia Tone of the Muscle

31. Isotonic contraction Isometric contraction Contractions based on tone

32. Stretch Reflex

33. Intrafusal muscle fibersare skeletal muscle fibres that comprise the muscle spindle and are innervated by gamma motor neurons. These fibers are proprioceptors that detect the amount and rate of change of length in a muscle. These fibers are walled off from the rest of the muscle by a collagen sheath. This sheath has a spindle or "fusiform" shape, hence the name "intrafusal." Intrafusal Muscle Fibre

34. Extrafusal muscle fiber is a term given to standard muscle fibers as to distinguish them from intrafusal muscle fibers. Extrafusal muscle fibers are innervated by alpha motor neuron and generate tension by contracting, thereby allowing for skeletal movement. Extrafusal Muscle Fibers

35.  motor neuron supply intrafusal fibers When a muscle is stretched stretch receptors in the intrafusal fibres are stimulated Impulse is transmitted to the spinal cord  motor neuron is stimulated muscle is contracted Stretch Reflex

36. Golgi Tendon

37. Sensory receptor that inhibits tension development in a muscle and initiates tension development in the antagonist muscles KEY: sense tension stimulated by the presence of active tension in a muscle Golgi Tendon Organ

38. Inhibits muscle tension in the muscle generating too much force and initiates development of muscle tension in the antagonist muscle (excites) Golgi Tendon Organ- Action

39. Questions

40. Textbook of Medical Physiology -Guyton & Hall www.youtube.com Bibliography