located between the left ventricle and the aorta; closes when the left ventricle is finished contracting, allowing blood to flow into the aorta and preventing blood from flowing back into the left ventricle
What is the circulatory system?
transportation system of the body; consists of the heart, blood vessels, and blood
What is the left atrium?
receives oxygenated blood from the lungs
What is the pericardium?
double-layered membrane, or sac, that covers the outside of the heart
What is the septum?
muscular wall that separates the heart into a right side and a left side
What are arrhythmias?
abnormal heart rhythms and can be mild to life threatening
What is diastole?
brief period of rest
What is the left ventricle?
receives blood from the left atrium and pumps the blood into the aorta for transport ot the body cells
What is the plasma?
approximately 90 percent water, with many dissolved substances; makes up part of the blood
What is systole?
period of ventricular contraction
What are arteries?
carry blood away from the heart
What is the endocardium?
smooth layer of cells that lines the inside of the heart and is continuous with the inside of blood vessels
What are leukocytes?
formed in the bone marrow and lymph tissue; main function is to fight infection
What is the pulmonary valve?
located between the right ventricle and the pulmonary artery; closes when the right ventricle has finished contracting, preventing blood from flowing back into the right ventricle
What are thrombocytes?
fragments or pieces of cells
What is blood?
liquid that flows through circulatory system
What are erythrocytes?
produced in the red bone marrow at a rate of about one million per minute
What is the mitral valve?
located between the left atrium and left ventricle; closes when the left ventricle is contracting, allowing blood to flow into the aorta and preventing blood from flowing back into the left atrium
What is the right atrium?
receives blood as it returns from the body cells
What is the tricuspid valve?
located between the right atrium and the right ventricle; closes when the right ventricle contracts, allowing blood to flow to the lungs and preventing blood from flowing back into the right atrium
What are capillaries?
connect arterioles with venules
What are hemoglobins?
complex protein composed of the protein molecule called globin and the iron compound called heme
What is the myocardium?
the muscular middle layer
What is the right ventricle?
receives blood from the right atrium and pumps the blood into the pulmonary artery, which carries the blood to the lungs for oxygen
What are veins?
blood vessels that carry blood back to the heart