cardiovascular system
The body system that consists of the heart, blood vessels, and blood, aka the circulatory system.
heart
a hollow, muscular organ that pumps blood throughout the body
pacemaker
A group of heart cells in the right atrium which send out signals that make the heart contract and that regulates heartbeat.
ventricle
A lower chamber of the heart that pumps blood out to the lungs and body.
valve
A flap of tissue in the heart or a vein that prevents blood from flowing backward.
arteries
blood vessel that carries blood away from the heart
capillaries
A tiny blood vessel where substances are exchanged between the blood and the body cells.
veins
a blood vessel that carries blood from the capillaries toward the heart
aorta
the largest artery in the body
coronary artery
The artery that supplies blood to the heart itself.
pulse
The rhythmic contraction and expansion of the arteries with each beat of the heart
diffusion
The process by which molecules move from an area of higher concentration to an area of lower concentration.
pressure
The force exerted on a surface divided by the total area over which the force is exerted.
blood pressure
The pressure of the circulating blood against the walls of the blood vessels
plasma
The liquid part of the 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
hemoglobin
An iron-containing protein that binds chemically to oxygen molecules.
white blood cell
A blood cell that fights disease.
platelet
tiny bits of protoplasm found in vertebrate blood that help blood clot
lymphatic system
A network of veinlike vessels that returns the fluid that leaks out of the blood vessels back to the bloodstream.
lymph
The fluid that the lymphatic system collects and returns to the bloodstream.
lymph node
a small knob of tissue in the lymphatic system that filters lymph, trapping bacteria and other microorganisms that cause disease
respiration
The process by which cells break down simple food molecules such as glucose to release the energy they contain.
mucus
A thick, sticky liquid produced by the body.
cilia
The hairlike projections on the outside of cells that move in a wavelike manner.
pharynx
The throat
trachea
windpipe; tube through which air moves in the respiratory system
bronchi
two short branches located at the lower end of the trachea that carry air into the lungs.
lungs
An organ found in air-breathing vertebrates that exchanges oxygen and carbon dioxide with the blood
alveoli
Tiny sacs of lung tissue specialized for the movement of gases between air and blood
diaphragm
A large muscle located at the bottom of a mammal's ribcage that functions in breathing.
larynx
The voice box.
vocal cords
Folds of connective tissue that stretch across the opening of the larynx that vibrate and produce a person's voice
atherosclerosis
A condition in which an artery wall thickens from a buildup of fatty materials
heart attack
A condition in which blood flow to part of the heart muscle is blocked, causing heart cells to die.
hypertension
A disorder in which blood pressure is consistently higher than normal (a reading of 140/90 mm Hg or greater), also called high blood pressure
stroke
Death of brain tissue that can result when a blood vessel in the brain is either blocked by a clot or bursts.
emphysema
A serious disease that destroys lung tissue and causes breathing difficulties.
bronchitis
An irritation of the breathing passages in which the small passages become narrower than normal and may be clogged with mucus.
asthma
A respiratory disorder in which the airways in the lungs narrow significantly
pneumonia
An infection that causes fluid to accumulate in the alveoli, decreasing the lungs' ability to take in oxygen and remove carbon dioxide.
shock
Dangerous condition in which insufficient gas exchange in the lungs leads to a lack of oxygen in the vital organs.
Blood
Carries needed substances to cells and carries waste products away from cells. In addition contains cells that fight disease.