Myology

Question 1

Define muscle and list its parts

Answer 1

Muscle - comprised of muscle tissue and connective tissue, the active portion of the musculoskeletal system
2 parts - belly and attachments

Question 2

Describe the muscle belly and its components

Answer 2

Muscle belly is the contractile portion of the muscle which shortens and relaxes.
Connective tissue compoenets:
- Endomysium - around individual muscle fibers
- Perimysium - divides groups of muscle fibers
- Epimysium - surrounds entire muscle

Question 3

Describe muscle attachments and its components

Answer 3

Muscles attachments are formed of connective tissue.
3 basic forms:
- Tendon - cord-like extension from muscle belly
- Aponeurosis - flat, sheet-like connective tissue
- Fleshy - directly to periosteum

Question 4

Describe skeletal muscle and its functions

Answer 4

• Attaches to bones, organs, other muscles
• Capable of contraction in response to nerve impulses
• Relaxation causes muscle to lengthen
• Functions in locomotion, phonation, respiration, digestion, etc

Question 5

List and describe the locomotor actions of mucles

Answer 5

Extension - when extensor angle becomes smaller
Flexion - when flexor angle becomes smaller
Rotation - when the limb moves about the axis (includes supination and pronation)
Abduction - away from
Adduction - towards
Circumduction - circular

Question 6

How are muscles involved in muscle action

Answer 6

Prime Mover - subject, muscle in question
Synergist - will do something in common with prime mover, there can be multiple synergists
Antagonist - will do something opposite of prime mover
Fixator - inhibits motion

Question 7

List and describe accessory structures

Answer 7

Bursa - fluid-filled sac, sits between tendon and bony prominence
Tendon Sheath - surrounds tendon
Retinaculum fascia - made of collagen fibers, holds tendon in place
Sesamoid bone - embedded in tendon