Embryology and Anatomy Flashcards
1
Q
What are extrafusal muscle fibers?
A
Muscle fibers that respond to movement
2
Q
What are intrafusal muscle fibers?
A
Muscle fibers contained within stretch receptors
3
Q
Where do most primary myopathies occur?
A
Extrafusal fibers; NOT intrafusal fibers
4
Q
Check out this sarcomere! What are the labeled structures?
A
- M line
- H zone
- A band
- I band
- Z band
5
Q
What is the purpose of the Transverse Tubule System?
A
To allow electrical stimuli to proceed along the muscle fiber surface and become diffusely and rapidly internalized
6
Q
Type I muscle fibers are…
A
slow-twitch and fatigue resistant
7
Q
Type II muscle fibers…
A
are either IIA - fast twitch/fatigue resistant or IIB - fast twitch/fatigue sensitive
8
Q
What color are fast twitch muscles? Slow twitch?
A
Pale; Red
9
Q
What likely influences fiber type?
A
Lower motor neuron innervation
