Myology: The Study of Muscles (Anatomy: 1st Semester Lecture 5)

Myology is the study of Muscles. In this Presentation Muscle tissue, Structure of skeletal muscle, Classification will be discussed.

1. Lecture 5
Muscle tissue, Structure of skeletal
muscle, Classification

2. Muscle Tissue: Composed of contractile unites possessing the
properties of
Excitability
Contractility
Extensibility
Elasticity
Functional Unit:
Muscle fiber
Smooth muscle fiber  Visceral
Striated muscle  Skeletal / Cardiac

3. Skeletal Muscle
Functions:Provides force for Movement and Posture
Stabilizes Joints
Generates heat
Attachments
Origin /Insertion
Direct/Indirect (Tendon/Aponeurosis)
Transmits forces (Fiber orientation?)
Belly
Generates force

4. Structure
Fiber covered by Endomysium—Sarcolemma
Fascicle covered by Perimysium
Muscle covered by Epimysium  Epitenon

5. Muscle force is a function of
Number of muscle fibers
Pennation Angle
Pennation Angle
Unipennate Muscles
Bipennate Muscles
Multipennate Muscles
Multipennate Bipennate

6. Accessory Structures
Fascia
Bursa
Tendon Sheath
Extensive Blood Supply
Extensive Innervations:
Motor Unit
Spindles/Golgi tendons endings/
free nerve endings/Pacinian
corpuscles
Regeneration of muscle tissue is possible

7. Spindle-shaped (fusiform)
Sheet like (planus)
CLASSIFICATION
Shapes

9. CLASSIFICATION
Functional:Prime Movers / Agonists
Synergist
Antagonists
Specific Action:
Flexor/Extensor
Adductor/Abductor
Supinator/Pronator
Sphincter/Dilator
Levator/Depresssor
Rotator
Number of joints crossed:
Uniarticular
Biarticular
Polyarticular

10. Developmental Origin and Innervation:
Somatic muscles – somatic motor innervation
Visceral muscles – visceral autonomic motor innervation
Composition:
White fibers: More myofibrils  more force
Less myoglobin  short duration
Red Fibers: Less myofibrils  weak force
More myoglobin  long duration

11. NAMING CONVENTIONS
Action
Shape
Regional Location
Direction of fibers
Number of heads
Number of bellies
Attachment sites
Relative position