Term | Definition |
circulatory system | the system that transports blood, nutrients, and waste around the body; includes the heart, and all blood vessels (arteries and veins) |
heart | the muscular organ that pumps blood via the circulatory system to the lungs and body |
blood vessel | a hollow tube that carries blood to and from body tissues |
blood | the bodily fluid in which blood cells are suspended. |
open circulatory system | a circulatory system in which vessels open to the animal's body cavity (ie. in a grasshopper) There is no difference between interstitial fluid and blood and the circulating mixture is called hemolymph. |
closed circulatory system | a circulatory system in which the circulating blood in contained in vessels and kept separate from interstitial fluids |
pulmonary artery | the large blood vessel that carries blood from the heart to the lungs |
pulmonary vein | blood vessel that carries blood from the lungs to the the heart (left atrium) |
aorta | an artery that carries blood directly from the heart to other arteries heading to body tissues; largest vessel in the body |
atrioventricular valve | a valve between the ventricle and atrium (tricuspid - right & mitral/bicuspid - left) |
semilunar valve | a valve between the ventricles and large arteries (aortic valve & pulmonary valve); carries blood away from heart and prevents backflow |
arteries | vessels that carry blood away from the heart; small diameter arteries are arterioles; have highly elastic walls |
veins | vessel that carry blood to the heart; small diameter veins are venules; have thinner walls than arteries and larger inner diameter with one way valves to prevent backflow |
capillaries | network of one cell thick vessels where gases, nutrients, wastes and other materials are transferred from blood to tissues cells, and from cells to blood |
blood | composed of plasma (water, gases, proteins, sugars, vitamins, minerals and waste) and blood cells (red blood cells, white blood cells, and platelets) |
sinoatrial (SA) node | the modified heart cells in the right atrium that spontaneously generate the rhythmic signals that cause the atria to contract (start of heartbeat) |
atrioventricular (AV) node | the specialized heart cells near the junction of the atria and ventricles that cause the ventricles to contract (strong contraction of heartbeat) |
blood pressure | the force that blood exerts on the walls of the blood vessels |
systolic pressure | the pressure generated in the circulatory system when the ventricles contract and push blood from the heart (higher pressure than diastole). |
diastolic pressure | the pressure generated in the circulatory system when the ventricles fill with blood (atria are contracting) |
sphygmanometer | a medical device for measuring blood pressure |
stethoscope | a medical device for listening to body sounds including the heartbeat and breath sounds. |
arteriosclerosis | a general term to describe several disorders in which the walls of the arteries thicken and lose elastic properties (aka. hardening of the arteries, atherosclerosis); plaque forms in vessels; can lead to heart attack or obstruction of other key arteries |
aneurym | is a bulge in an artery due to a weakened area of the arterial wall which is at risk of bursting. Internal bleeding can lead to death. |
arrhythmia | an irregularity in the speed or rhythm of the heart beat; can cause insufficient blood supply to brain or other organs. Treated with a pacemaker. |
stroke | when arteries supplying the blood vessels of the brain are damaged. Ischemic stroke is a blockage and brain tissue is deprived of oxygen and nutrients. Hemorrhagic stroke is a bleed into brain tissue. |