The body system that consists of of the heart, blood vessels, and blood; circulatory system.
A hollow, muscular organ that pumps blood throughout the body.
Each of the two upper chambers of the heart that receives blood that comes into the heart.
A group of cells located in the right atrium that sends out signals that make the heart muscle contract and that regulates heartbeat rate.
A lower chamber of the heart that pumps blood out to the lungs and body.
A flap of tissue in the heart or a vein that prevents blood from flowing backward.
A blood vessel that carries blood away from the heart.
A tiny blood vessel where substances are exchanged between the blood and the body cells.
A blood vessel that carries blood back to the heart.
The largest artery in the body
An artery that supplies blood to the heart itself.
The alternating expansion and relaxation of an artery wall as blood travels through an artery.
The process by which molecules move from an area of higher concentration into an area of lower concentration.
The force exerted on a surface divided by the total area over which the force is exerted.
The pressure that is exerted by the blood against the walls of blood vessels.
The liquid part of blood.
red blood cell
A cell in the blood that takes up oxygen in the lungs and delivers it to cells elsewhere in the body.
An iron-containing protein that binds chemically to oxygen molecules.
white blood cell
A blood cell that fights disease.
A cell fragment that plays an important part in forming blood clots.
The failure of the circulatory system to provide adequate oxygen-rich blood to all parts of the body.
A network of veinlike vessels that returns the fluid that leaks out of blood vessels to the bloodstream.
The fluid that the lymphatic system collects and returns to the bloodstream.
A small knob of tissue in the lymphatic system that filters lymph, trapping bacteria and other microorganisms that cause disease.
The process by which cells break down simple food molecules such as glucose to release the energy they contain.
A thick, sticky liquid produced by the body.
The hairlike projections on the outside of cells that move in a wavelike manner.
The windpipe; a passage through which air moves in the respiratory system.
The passage that direct air into the lungs.
An organ found in air-breathing vertebrates that exchanges oxygen and carbon dioxide with the blood.
Tiny sacs of lung tissue specialized for the movement of gases between air and blood.
A large muscle located at the bottom of a mammal's rib] cage that functions in breathing.
The voice box.
Folds of connective tissue that stretch across the opening of the larynx and produce a person's voice.
A condition in which an artery wall thickens from a buildup of fatty materials.
A condition in which blood flow to part of the heart muscle is blocked, causing heart cells to die.
A disorder in which a person's blood pressure is consistently higher than normal; also called high blood pressure.
Death of brain tissue that can result when a blood vessel in the brain is either blocked by a clot or bursts.
A serious disease that destroys lung tissue and causes breathing difficulties.
An irritation of the breathing passages in which the small passages become narrower than normal and may be clogged with mucus.
A respiratory disorder in which the airways in the lungs narrow significantly.
dangerous condition in which insufficient gas exchange in the lungs leads to a lack of oxygen in the vital organs.
An infection that causes fluid to accumulate in the alveoli, decreasing the lungs' ability to take in oxygen and remove carbon dioxide.