MUSCLE PHYSIOLOGY

PHYSIOLOGY

MUSCLE CONTRACTION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
The all-or-none response means
A
all of the muscles in a region contract together
B
all of the muscle fibers within a muscle contract together
C
when a muscle fiber contracts, it contracts completely
D
when a muscle fiber contracts, all of its ATP is changed to ADP
Explanation: 

Detailed explanation-1: -The all-or-none law is the principle that the strength by which a nerve or muscle fiber responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fiber will give a complete response; otherwise, there is no response.

Detailed explanation-2: -Each muscle fiber contracts on an “all or nothing” principle; a muscle fiber either contracts fully or not at all, and all the fibers in a single motor unit contract at the same time. When a muscle is required to contract during exercise, not all motor units are contracted at the same time.

Detailed explanation-3: -A twitch occurs when one muscle fiber contracts in response to a command (stimulus) by the nervous system. The time between the activation of a motor neuron until the muscle contraction occurs is called the lag phase (sometimes called the latent phase).

Detailed explanation-4: -The all-or-nothing law is an important principle that describes how nerve cells either fire at full strength or do not. Because of this, important information does not lose strength as it is carried to the brain, ensuring that people are able to respond to environmental stimuli. American Psychological Association.

There is 1 question to complete.