The right atrium receives blood returning from others parts of the body through the superior vena cava and the inferior vena cava.
Explanation:
The pathway of circulation begins in the right atrium which receives the carbon dioxide-rich deoxygenated blood returning through the systemic circulation.
The deoxygenated blood from regions superior to the heart, i.e., the head, neck, shoulder areas are collected through the superior vena cava and that from the parts inferior or lower to the heart like visceral organs, extremities, trunk, hip etc are brought through the inferior vena cava.
Both these venous systems (superior and inferior) fill the right atrium.
The right atrium then pumps the deoxygenated blood to the right ventricle via the tricuspid valve.
The right atrium is filled with blood during diastole.
Answer: Foods with calcium
The amount of bone tissue in the skeleton or bone mass can keep growing until the age of 30. It is recommended to eat food with calcium prior to this age for maximum strength and density of the bones. Examples of food rich in calcium are dairy foods, green leafy vegetables, beans, nuts, fish and a lot more.
<span>a. an element is a substance that cannot be broken down</span>
Answer:
D. antigen only come from microbes
Explanation:
Antigens are substances which elicits a response by the antibodies. Antigens Antigens include proteins, nucleic acids, lipoproteins, glycoproteins, and certain large polysaccharides.
They parts of antigen molecules that initiate immune responses are called epitopes or antigenic determinants.