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36 terms

Ch 42: Circulatory and Respiration Systems

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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
arteries
blood vessels that carry blood away from the heart
capillaries
Tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body.
atrium
upper chamber of the heart that receives and holds blood that is about to enter the ventricle
ventricle
a chamber of the heart that receives blood from an atrium and pumps it to the arteries
single circulation
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
double circulation
a circulatory system consisting of separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit
left ventricle
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
sinoatrial node
pacemaker 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.
semilunar valves
found at each of the two exits of the heart and prevents backflow of blood when the blood pumps
atrioventricular AV node
second pacemaker of the heart, impulses from SA node travel to here
aorta
The largest artery in the body; it conducts freshly oxygenated blood from the heart to the tissues.
endothelium
thin layer of cells that lines heart cavities and blood vessels
systolic pressure
blood pressure in the arteries during contraction of the ventricles
diastolic pressure
the pressure in the arteries when the heart is at rest
vasoconstriction
the contraction of smooth muscle in artriole walls; increase blood pressure
vasodilation
relaxation of smooth muscles in the artrioles; causes blood pressure to fall
nitric oxide
reactive gas that plays a role in many body processes; promotes relaxation of smooth muscles around blood vessels which dilates and improves blood flow
erythrocytes
red blood cells that transfer oxygen and don't have a nucleus
leukocytes
white blood cells that function in defense
platelets
irregularly, shaped cell fragments that help clot blood
monocytes
a leukocyte that is able to migrate into tissues and transform into a macrophage which devours bacteria and antigens
neutrophils
A type of white blood cell that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease.
basophils
a type of WBC that promotes inflammation and participates in allergic responses.
eosinophils
white blood cell that are responsible for combating infection by parasites
lymphocytes
Make antibodies to destroy foreign pathogens; Make antibodies to destroy foreign pathogens
Countercurrent exchange
____ 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
Spiracles
Oxygen enters of carbon dioxide exits the trachea through openings called
Bronchi
Trachea bringes into 2 ____ which enter the lungs
Air rushes into the lungs
When the lunge volume increases, the air pressure with the lungs decreases which causes
There is an increase in respiratory rate
When carbon dixiode is in the blood, the pH drops so..
Lymph nodes
Enlarged bodies throughouit the lymphatic system, act as cleaning filters and as immune respone centers that defend against infection