Chapter 13 (Part 4) Flashcards
what two factors contribute to blood pressure?
- the heart is always pumping
- always experiencing some level of contraction (pressure), so that blood always flows “forward”
the arterial vasculature is composed of arteries, arterioles, and ends at capillaries. which of these has the greatest impact on altering BP and why?
which: arterioles
why: makes it hard for arteries to drain in when they’re constricted
what are the two circuits of the circulatory system? what is the job of each?
pulmonary: lungs
general: everything else
why is the pulmonary artery depicted in blue and the pulmonary vein in red?
red: oxygenated
blue: deoxygenated
blue vessel: oxygenated or deoxygenated
deoxygenated
red vessel: oxygenated or deoxygenated
oxygenated
why is the blood pressure in the pulmonary circuit so much less than the general circulatory system?
- doesn’t have to travel as far
- in fact, if the same pressure was present in the pulmonary circuit as was present in the rest of the body, too much plasma would enter interstitium and you we wouldn’t be able to get it out –> fluid edema = can’t breathe and you drown yourself
what would happen if the vessel pressure was the same in the pulmonary circuit as in the rest of the body?
- in fact, if the same pressure was present in the pulmonary circuit as was present in the rest of the body, too much plasma would enter interstitium and you we wouldn’t be able to get it out –> fluid edema = can’t breathe and you drown yourself
why are arteries said to function as pressure reservoirs?
by dilating or contracting they regulate pressure
elastic walls means they can expand = bigger diameter = decreased resistance = regulate pressure
why is it significant that arteries are said to function as pressure reservoirs?
because it keeps blood pumping in one direction
what protein within the vessel wall provides recoil?
elastin
what protein provides protection from tearing?
collagen
why are veins said to function as blood reservoirs?
60% of blood volume is contained within the venous system
how is veins functioning as blood reservoirs useful for cardiac output?
changing vessel diameter alters venous holding capacity, because most of the blood is in the veins bebe
how does vasoconstriction affect arterial blood flow?
makes it go slower.
decreased diameter means increased turbulent flow. bouncing off interior wall becomes a problem and blood can’t flow ver well.
