Answer:
the esophageal sphincter
Explanation:
This muscle opens and lets food and liquid enter the stomach and closes to prevent the food and liquid from leaking back into the esophagus, however if it is not working properly it could open and close at the wrong times
When you’re sick your immune system produces antibodies to protect you and fight off the infection
The answer should be, Identity.
It usually take half lives
Answer:
The blood circulatory system, also called the cardiovascular system, consists of the heart and the blood vessels that run throughout the body
