Answer:
By action potential nerve contract the muscle
Explanation:
The muscle contract when the nervous system sends action potential to the muscle. So the nervous system delivers signal to muscle, the first signal reaches the neuromuscular junction. The signals are passed by a chemical messenger called neurotransmitter release by motor neurons, the chemicals bring reaction and shorten the muscle fibre. When neurotransmitter are absent or reduce in concentration the process reverse and muscle relax again.
Answer:
the somatic nervous system and the autonomic nervous system
Explanation:
The somatic nervous system is responsible for both sending and receiving sensory and motor information to the central nervous system.
The autonomic nervous system is responsible for regulating involuntary body functions. For example, heart rate, breathing, and digestion.
Answer:
B. interconnected
Explanation:
All the systems in our bodies (humans are indeed animals) are connected with each other to create a functional being. The blood flows throughout the body, providing nutrients; the bones support the structure and protect the heart and lungs. They work together.
Why not A: The systems are all completely necessary. There's nothing extraneous in our bodies, because extraneous stuff takes up energy, and our biology is incredibly economical.
Why not B: They're not interchangeable. How would you like your bones to turn to blood? Uh-huh.
Why not D: They interact with each other consistently, so they're not separate or segregated.
Answer:
A series if reaction break and rrarrange csrbon bonds to release energy ang carbon dioxide.
