1.
aorta: 
This is the name of the first vessel that blood enters when it leaves the heart through the left ventricle.
2.
Atrium: The upper chambers of the heart that receive blood
from the body and the lungs. Atria is the plural
3.
Capillaries: 
Narrow thin walled blood vessels carrying blood to
cells
4.
coronary arteries: 
Blood vessels that supply the heart muscle with
blood to the walls of the heart, supplying the heart muscles with food and oxygen etc
5.
coronary veins: These are the vessels that drain blood from the walls of the heart to the coronary sinus
6.
deoxygenated blood: This is what blood that has low levels of oxygen is called. It is found in the veins carrying blood back to the heart
7.
heart: 
This is the organ that is largely responsible for creating the blood pressure that is necessary to move the blood through the vessels of the circulatory system
8.
left atrium: This is the name of the heart chamber that receives blood from the pulmonary veins and send blood to the left ventricle.
9.
left ventricle: 
This is the heart chamber that receives blood from the left atrium and pumps blood into the aorta
10.
Oxygenated blood: Blood that has high levels of dissolved oxygen.
11.
right atrium: 
This is the name of the heart chamber that receives blood from the vena cava and send blood to the right ventricle.
12.
right ventricle: This is the heart chamber that receives blood from the right atrium and pumps blood into the pulmonary artery
13.
valves: These structures allow blood to flow one way/ prevents back-flow in the circulatory system
14.
veins: 
Thin walled blood vessel which carries blood towards the heart.
15.
vena cava: 
This is the name of a large vessel that transports blood to the right atrium of humans. It primarily carries blood from the body to the heart
16.
ventricles: These are often described as the pumping chambers of the heart. There is one on the left and one on the right side. They provide most of the pressure necessary to move blood through the vessels of the body. They have thick walls compared to the atria. Note that the one on the left has a thicker wall than the one on the right.
