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24 terms

AP Biology Circulation and Gas Exchange

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gills
Structures (outgrowths from the body) that create a large surface area over which gas exchange occurs.
tracheae
Chitin-lined tubes in insects that permeate their bodies. Oxygen enters (or CO2 exits) through spiracles (openings).
pharynx
Human nasal cavity.
larynx
Human "voice box" that contains the vocal chords.
epiglottis
Covers the trachea when an animal is swallowing, preventing the entrance of solid and liquid material.
bronchi (bronchioles)
In humans, the trachea branches into two ____, which enter the lungs and then repeatedly branch, forming narrower tubes called (______).
alveolus
Each bronchiole branch ends in a small sac called an ____, which is surrounded by blood-carrying capillaries.
arteries (arterioles)
Vessels moving away from the heart (closed circulatory system). Branch into (_____)
capillaries
Smallest blood vessels.
veins
Returns blood to the heart.
ventricles
Portions of the heart (left and right) which pump out the blood into the arteries. Have thicker walls.
atria
Portions of the heart (left and right) that receive blood from the veins.
AV
___valve prevents between blood from moving backward into the the atria when the ventricles (left and right) contract.
semilunar
___valve prevents backflow of blood into the ventricle after the ventricles relax (connects the ventricles and the aorta on the left side and the ventricles and the pulmonary trunk on the right side).
pulmonary
___circuit is the blood pathway between the heart and lungs.
systemic
___circuit is the circulation pathway between the heart and body.
SA (sinoatrial) (or pacemaker)
___node, located in the upper wall of the right atrium, spontaneously initiates the heart/cardiac cycle by simultenously contracting both atria and also by sending a delayed impulse that stimulates the AV (atrioventricular) node
systole
In the ___ phase, blood is forced through the pulmonary arteries and aorta. Occurs when the ventricles CONTRACT.
diastole
In the ___ phase, ventricles RELAX, the semilunar valve closes to prevent backflow.
veins
Blood moves through the ___ due to the movements of adjacent skeletal muscles which squeeze the blood vessels (not because of the contractions of the heart).
lymphatic
The ___ system is a second network of capillaries and veins through which some interstitial fluids (fluids that bathes/surrounds the cells) and wastes return to the circulatory system. Acts as a filter (with lymph nodes to be cleaning filters and ward against infection).
leukocytes
Another word for white blood cells.
platelets
Cell fragments involved in blood clotting
plasma
Liquid portion of the blood that contains various dissolved substances.