-Atrium- Two upper chambers of the heart, that contract at the same time during a heartbeat.
-Ventricles-Two lower chambers of the heart, that contract at the same time, during a heartbeat.
-Coronary circulation- it’s the flow of blood to and from the tissue of the heart.
-System circulation- largest part of the circulatory system, in which oxygen-rich blood flows to all the organs and body tissues , Except the heart and lungs, and oxygen –poor blood is returned to the heart.
-Arteries- blood vessel that carries blood away from the heart, and has thick, elastic walls made of connective tissue and smooth muscle tissue.
-Veins- blood vessel that carries blood back to the heart, and has one-way valves that keep blood moving toward the heart.
- Capillaries- Microscopic blood vessel that connects arteries and veins.

Cardiovascular system

-Coronary circulation is the flow of blood to and from the tissues of the heart.
-Pulmonary Circulation is the flow of blood through the heart, to the lungs, and back to the heart.
-Oxygen-rich blood is moved to all tissues and organs of the body, except the heart and lungs, by systemic circulation.

Blood Vessels

-Arteries carry blood away from the heart.
-Veins carry blood back to the heart.
-Arteries and veins are connected by cappilaries.

Blood Pressure

-The force of the blood on the walls of the blood vessels is called blood pressure.

Cardiovascular disease

-Atherosclerosis occrus when fatty deposits build up on arterial walls.
-High blood pressure is called hypertension.

Parts of Blood

-Plasma is made mostly of water, with nutrients, minerals, and oxygen dissolved in it.
-Red blood cells contain hemoglobin, which carries oxygen and carbon dioxide.
-White blood cells control infections and viruses.
-Blood clotting factors and platelets help blood to clot.

Blood Types

-People can inherit one of four types of blood and an Rh factor.
-Type A,B, and AB blood all have antigens. Type O blood has no antigens.

Diseases of blood

-Anemia is a disease of red blood cells.
-Leukemia is a disease that produces immature white blood cells that don´t fight infections.