Physiology

Question 1

myosin is dark/light and thin/thick filaments

Answer 1

dark and thick

actin in the opposite

Question 2

describe the z line

Answer 2

connects the thin filaments of two adjacent sarcomeres - has Z shape

Question 3

describe the A band

Answer 3

band of sarcomere with thick myosin filaments and overlapping portion of thin filaments

Question 4

describe the H zone

Answer 4

area of A band in the middle where the thin filaments dont reach

Question 5

describe the M line

Answer 5

area extending vertically down the A band and H zone

Question 6

describe the I band

Answer 6

area that has remaining portion of thin filaments that dont overlap the thick myosin

Question 7

ATP is required for contraction but not relaxation of muscle

Answer 7

false required for both

Question 8

what is calcium required for

Answer 8

to turn on cross bridge formation

Question 9

describe what happens for muscle contraction to occur

Answer 9

binding of actin and myosin triggers power stroke - pulls thin filament inwards - muscle fibre excited - Ca binds with troponin - pulling troponin/tropomyosin complex aside exposing binding site - cross bridge binding occurs

Question 10

what is ATP required to do in skeletal muscle contraction

Answer 10

release cross bridges and pump calcium back into sarcoplasmic reticulum