Answer: movement is always voluntary
Explanation:
Muscles are contractile:
- Contractility is the ability of muscle cells to forcefully shorten. Think of having the ability to flex a muscle.
Muscles are excitable:
- Excitable tissue can conduct or transmit electrical impulses. Basically, it can react to stimulus, which may be delivered from a motor neuron or a hormone. For example, the hormone epinephrine helps muscles to produce force.
Muscles respond to stimulus:
- well since muscles are an excitable tissue, they can react to stimulus. (see answer above)
————————
Muscle movement is NOT always voluntary:
- Some muscle movement is voluntary, which means it is under conscious control. For example, a person decides to open a book and read. Other movements are involuntary, meaning they are not under conscious control, such as the contraction of your pupil in bright light, breathing, blinking, your heart beating, etc.
- Therefore, the correct answer is:
movement is always voluntary
hope this helps :)
