The Physiology of Muscle Contraction - THE ALL-OR-NONE PRINCIPLE Flashcards
1
Q
What is THE ALL-OR-NONE PRINCIPLE?
A
Contraction of a single muscle cell
2
Q
When a muscle fiber contract what does it do?
A
It always contracts completely
or it doesn’t contract at all.
3
Q
Why does muscle fiber always contracts as strongly as it
can?
A
This happens because its sarcomeres always shorten to
their fullest extent.
4
Q
What is Threshold?
A
Minimum amount of electricity (the stimulus) needed to cause an action potential in the muscle.
5
Q
What happens with Subthreshold stimulus to muscle fiber?
A
No action potential produced
no muscle contraction
6
Q
What happens with Threshold stimulus?
A
Action potential produced
Contraction of fiber
7
Q
What happens with Above-threshold stimulus?
A
action potential produced
contraction of fiber
