Myology

this slide show gives brief discussion about muscle structure and its functions

1. Myology
Dr. Radhika Chintamani
Asst. Professor
OMT

2. Definition of myology
Contents of myology
Definition of muscle, myocyte, muscle fibril, muscle fiber
Structure of muscle, myocyte
Orientation of muscle fiber
Contents

3. Myology: study of structure, arrangement and action of muscle tissue.
Its not only the study of muscle tissue, but also, the contents that its
made up of and fascia covering it.
Muscle tissue is made up of myocytes, contractile proteins,
structural protiens, contractile unit, motor unit and muscle fibers.
Myology

4. Myocyte: muscle cell.
Muscle fiber: strands of fibers made up of myocyte arranged in
series.
Fascicle: group of muscle fibers surrounded by a connective tissue.

5. Fascia: covering of muscle.
Sarcolemma: covering of muscle fiber
(muscle cell).
Muscle fiber is made up of number of
myofibril.
Fascicle: group of muscle fibers.
STRUCTURE OF MUSCLE FIBER

6. Basically two types: contractile and structural.
Contractile proteins: help in muscle contraction, which are actin,
myosin, troponin and tropomyosin.
Structural proteins: help in maintenance of structure of muscle,
which are intermediate filaments, desmin and titin.
Proteins of Muscle

7. Myofibril is composed of thick myofilaments of the protein Myosin
and thin myofilaments of the protein Actin.
Myosin and Actin: Contractile proteins of muscle, whose interaction
is essential for muscle contraction.
A. Contractile Proteins: Myofilaments

8. Contractile Protein structure.
Thin filament
String like strands. Each Actin is made up of 2 strands.
** Troponin: globular protein found in notches between actin strings.
** Tropomyosin: protein attached to each troponin molecule.
Both the above mentioned molecules are important in muscle contraction.
Actin

9. Thick myofilament.
Contractile Protein structure.
Head groups: a globular enlargements on myosin molecule, able to
swivel and have attachment site to the actin.
Myosin

10. Help in maintenance of structure of muscle.
Intermediate filaments: provides structural scaffold to the muscle fiber.
Desmin: involved in the transmission of force along the fiber and to
adjoining fibers.
Titin: maintaining the position of thick filament during muscle
contraction.
B. Structural Proteins

11. Called so because of alteration of actin and Myosin which looks
like a striated pattern on miscroscopic view.
Diagram of sarcomere: a contractile unit of muscle
Striated Muscle

12. How muscle contract???