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.
The term being describe above is the hormonal method in which it prevents the egg from reaching the ovaries to prevent the women from being pregnant during intercourse. There are different types of hormonal methods being used, and it does not only prevent eggs in reaching ovaries but it prevents also sperm in reaching the uterus.
Because types of chemicals in minerals need to form.
North Atlantic current could possibly be an answer
