open circulatory system
A circulatory system that allows the blood to flow out of the blood vessels and into various body cavities so that the cells are in direct contact with the blood
closed circulatory system
a circulatory system in which the oxygen-carrying blood cells never leave the blood vessels
Tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body.
upper chamber of the heart that receives and holds blood that is about to enter the ventricle
a circulatory system consisting of a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart
a circulatory system consisting of separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit
the chamber on the left side of the heart that receives arterial blood from the left atrium and pumps it into the aorta
superior vena cava
receives blood from the head and arms and chest and empties into the right atrium of the heart
inferior vena cava
receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart
AV (tricuspid) valve
A valve in the heart between each atrium and ventricle that prevents a backflow of blood when the ventricles contract.
found at each of the two exits of the heart and prevents backflow of blood when the blood pumps
The largest artery in the body; it conducts freshly oxygenated blood from the heart to the tissues.
reactive gas that plays a role in many body processes; promotes relaxation of smooth muscles around blood vessels which dilates and improves blood flow
a leukocyte that is able to migrate into tissues and transform into a macrophage which devours bacteria and antigens
A type of white blood cell that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease.
Make antibodies to destroy foreign pathogens; Make antibodies to destroy foreign pathogens
____ between the opposing movement of water and blood through blood vessels maximizes the diffusion of oxygen into the blood and carbon diozide into the water
Air rushes into the lungs
When the lunge volume increases, the air pressure with the lungs decreases which causes