The *heart* is the main organ of the circulatory system.
The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells.
The correct answer to this is:
“Astrocytes”
Astrocytes also called star cells due to their shape are the
most abundant glial cells in the brain. Extensions from these cells encase
capillaries and offer extra control over which materials enter or leave the
intercellular fluid of the CNS thus acting like a permeability membrane.
In the stomach, food undergoes chemical and mechanical digestion. Peristaltic contractions (mechanical digestion) churn the bolus, which mixes with strong digestive juices that the stomach lining cells secrete (chemical digestion). As food travels from your mouth into your digestive system, it's broken down by digestive enzymes that turn it into smaller nutrients that your body can easily absorb. This breakdown is known as chemical digestion.
The answer is all of the above
