aortic valve- largest artery in the body.

arrhythmias- abnormal heart rhythms and can be mild to life threatening.

arteries- carries blood away from the heart.

blood- flows through the circulatory system.

capillaries- connect arterioles with venules the smallest veins.

circulatory system- referred to as the transportation of the body.

  diastole- brief period of rest.

endocardium- smooth layer of cells the lines the inside of the heart and is continuous with the inside of blood cells.

erythrocytes- red blood cells.

hemoglobin- a complex protein composed of the protein molecule.

left atrium- receives oxygenated blood from the lungs.

left ventricle- pumps oxygenated blood from the lungs to the rest of the body.

leukocytes- white blood cells.

mitral valve-allows blood to flow to the aorta and preventing blood from flowing back into the left atrium.

myocardium- thickest layer, muscular middle layer.

pericardium- double layered membrane, covers the outside of the heart.

plasma- 90% water with many dissolved or suspended substances.

pulmonary valve- blood vessel that carries blood to the lungs.

right atrium- receives blood as it returns from the body.

right ventricle- receives blood from the right atrium and pumps the blood into the pulmonary artery.

septum- muscular wall that separates the heart into a right side and a left side.

systole- period of ventricular contraction.

thrombocytes- also knowns as platelets, helps stopping the bleeding.

tricuspid valve- regulate the flow of blood from the right atrium to the right ventricle. 

veins- blood vessels that carry blood back to the heart.