Objective 12 Flashcards
0
Q
How many muscle fibers are there per motor unit?
A
The number of muscle fibers per motor unit can vary from four to several hundred
1
Q
What is a motor unit?
A
The motor neuron and all the muscle fibers it innervates
2
Q
Which muscles have small motor units?
A
Muscles that control fine movements (fingers, eyes)
3
Q
Which muscles have large motor units?
A
Large, weight-bearing muscles (thighs, hips)
4
Q
Where are muscle fibers from a motor unit located?
A
They are spread throughout the muscle
5
Q
What does contraction of a single motor unit cause?
A
Contraction of a single motor unit causes weak contraction of the entire muscle
6
Q
Motor units in a muscle usually contract asynchronously, why?
A
Motor units in a muscle contract asynchronously which helps prevent fatigue
