Topic 7 Muscular System: Sarcomere

Question 1

• Structural unit of a myofibril in striated muscle and is composed of thin filaments (made of actin polymers) and thick filaments (made of protein myosin)

Answer 1

Note

Question 2

• Boundary of a single sarcomere and anchors thin filaments

Answer 2

Z-line

Question 3

• Center of sarcomere

Answer 3

M-line

Question 4

• Region containing thin filaments (actin) only (on the ends)

Answer 4

I-band

Question 5

• Region containing thick filaments (myosin) only (in middle)

Answer 5

H-zone

Question 6

• Area where actin and myosin overlap

Answer 6

A-band

Question 7

• H and I reduce during contraction while A does not

- Striations are result of alternating thin actin + thick myosin (I and A bands)

Answer 7

Note