I believe it is C) calcium-rich plates echinoderms and B) bones in mammals like vertebral
When an external stimulus crosses the threshold, a muscle fibre will respond.
<h3>The level of the threshold</h3>
- For the identification of the electrical activity carried out by the active muscles, the threshold level is a crucial consideration.
- A portion of the electrical activity carried out by the target muscles may be excluded if the chosen threshold level is higher than the overall activity.
<h3>What is the stimulus threshold for muscle contraction?</h3>
- A certain stimulus magnitude is necessary for muscle contraction.
- The threshold stimulus is the smallest amount of force needed for a stimulus to cause a muscle to contract in response.
- If the stimulus intensity is less than this threshold value, there is no response.
learn more about threshold here
brainly.com/question/28279471
#SPJ4
The muscles of the muscular system keep bones in place; they assist with movement by contracting and pulling on the bones. To allow motion, different bones are connected by joints which are connected to other bones and muscle fibers via connective tissues such as tendons and ligaments.
A medical term that means absence of an appetite is anorexia.
