2) Skeletal Muscle

Question 0

Functions of skeletal muscle

Answer 0

• movement
• stability of joints
• heat generation

Question 1

Histological structure of skeletal muscle

Answer 1

Peripheral nuclei, multinucleated, striated, T tubules at A/I, satellite cells for regeneration, red and white fibres, sarcomere between Z/Z line, MHAZI, A and I shorten during contraction

Question 2

Gross structure of skeletal muscle

Answer 2

Epimysium (muscle)
Perimysium (fascicles)
Endomysium (fibres)

Question 3

Types of skeletal muscle

Answer 3

• agonists, prime movers
• antagonists, oppose agonists
• synergists, assist agonists
• fixators, stabilise action of agonists)

Question 4

Describe compartment syndrome

Answer 4

Often two compartments (anterior and posterior) are only separated by a septum
Surroundings fascia are tough and inextensible
So increased pressure due to bleeding can lead to parasthesia or paralysis of the muscles

Question 5

Types of skeletal muscle fibres

Answer 5

1) Slow twitch (postural) aerobic, myoglobin, fatigue resistant, prolonged contraction
2a) fast twitch (walking, sprint) aerobic, myoglobin, mito, rich blood supply, some fatigue
2b) fast twitch (short intense movements) anaerobic, low myo/mito/blood supply, easy fatigue

Question 6

What is a contracture and what is the classic example of whole body contractures?

Answer 6

• continuous contraction, depleted ATP the myosin heads cannot detach from actin binding sites
• Rigor Mortis