Circulation Flashcards
function of the circulatory system?
bring nutrients to body cells and take away waste products
3 types of blood vessels that the cardiovascular system has?
arteries (& arterioles), capillaries, veins (& venules)
function of arteries?
- take blood away from the heart
- carry nutrients & blood high in O2 throughout body (except pulmonary artery)
- regulate BP by constriction (increase BP) and dilation (decrease BP)
why don’t arteries carry nutrients and blood through the pulmonary arteries?
the blood being carried is high in O2, and pulmonary arteries carry high levels of CO2
what allows stretching within the artery?
elastic fibers in inner arterial layer (endothelium)
what is the function of arterioles?
regulate BP by contracting to increase BP (narrow to increase BP)
what do capillaries join?
arterioles to venules
describe the exchange that occurs in capillary beds
-O2 & nutrients (ex: glucose) diffuse OUT of capillary into tissue fluid surrounding cells.
Some H20 also leaves.
-wastes (ex: CO2) diffuse INTO capillary
some H20 leaves the capillary, along with O2 and nutrients. where happens to the excess H20?
it is picked up by lymphatic cells
what do sphincters do?
open or close capillary beds to shunt (move) blood from one body system to another
what allows for the exchange of materials within the capillary beds?
very thin structure consisting of one layer of cells
function of veins?
have valves to prevent the back flow of blood (allows blood to flow in only 1 direction)
how do the veins allow blood flow?
by contraction of skeletal muscles
how are veins formed?
venules drain capillary blood and join to form a vein
difference b/t structure of arteries and veins?
veins have a thinner wall than arteries (less smooth muscle and connective tissue), but larger hole (bore) in center (veins have larger interior diameter)
function of venules?
- transport deoxygenated blood to <3 and wastes away from tissues
- return blood from cap. beds to veins
what are the 2 blood circuits in terrestrial vertebrates?
- pulmonary circuit
- systemic circuit
difference b/t pulmonary and systemic circuit?
- pulmonary: (from right to left side) from heart to lungs and back
- circuit: (from left to right side) from heart to everywhere else and back
internal structure of the heart
2 thin walled atria and 2 thick walled ventricles separated by a septum
function of coronary arteries?
supply the heart muscle with oxygen and nutrient rich blood
right atrium
receives deoxygenated blood from superior and inferior vena cava
-sends blood through atrioventricular valve to right ventricle
atrioventricular valve
prevent blood from flowing back into right atrium from the right ventricle
what do the chordae tendineae prevent?
(corrects)
- prevent atrioventricular valve from inverting by anchoring them to the walls of the ventricles
- prevent AV’s from opening in wrong direction
right ventricle
receives blood from right atrium, and pumps deoxygenated blood to the lungs through pulmonary trunk and pulmonary arteries.
Must go through a semi-lunar valve
