General

Question 1

Types of muscle

Answer 1

Smooth
Skeletal
Cardiac

Question 2

Describe the mechanism of skeletal and cardiac muscle contraction

Answer 2

Depolarisation - action potential causes Voltage gated Ca2+ ion channels to open
Neurotransmitter released
Spread of depolarisation
Conformational change - increase in calcium ions from calcium-induced calcium release
Ca2+ ions bind to troponin C
Cross-bridge formation - myosin head binds to actin where tropomyosin moves due to conformational change
Power stroke - ADP released and muscle contracts
Myosin head released and cycle repeats

Question 3

Describe the spread of depolarisation after neurotransmitter release in skeletal muscle

Answer 3

To the T-tubules to Dihydropyridine receptors

Question 4

Describe the spread of depolarisation after neurotransmitter release in cardiac muscle

Answer 4

Involves calcium-induced calcium release from the sarcoplasmic reticulum

Question 5

Mechanism of smooth muscle contraction

Answer 5

Depolarisation caused by action potential
Voltage gated Ca2+ ion channels open
Ca2+ ions bind to calmodulin
Myosin light chain kinase (MLCK) activated
Actin coupled with Myosin P causes contraction