Exam 2 Condensed Flashcards
What is the effective refractory period?
Na+ channels recovering but not enough for a new action potential
What vessel is the most distendible and why?
veins
hold most blood in body
What vessel has a large diameter and thin walls?
veins
What is flow measured in?
L/min
mL/min
small or large vessels are the dominant contributer to resistance?
small
What vessel is blood flow regulated in?
arterioles
What is the absolute refractory period?
no possible new action potential
What is the supranormal refractory period?
easier than normal to stimulate new action potential
What is the relative refractory period?
requires larger stimulus than normal
What is heart rate determined by?
rate of depolarization
What causes the 1st heart sound?
AV valves closing
What causes the 2nd heart sound?
semilunar valve
What do glomus cells do?
sense changes in O2, pH, and CO2
When the brain is ischemic, will the resistance is high or low?
low (less blood to brain)
In coronary circulation, when vasodilation is not enough _________ is released
adenosine
Where is renin released from?
juxtaglomeria cells in kidney
During exercise, TPR increases/decreases and why?
decreases
(more blood flow to muscles)
Why are cardiac muscle cells depolarizations longer than other cells?
Ca2+ must be brought into cell from outside
Where does the AV valve close on a wiggers diagram?
A
Where does the AV valve open on a wiggers diagram?
D
Where does the semilunar valve close on a wiggers diagram?
C
Where does the semilunar valve open on a wiggers diagram?
B
Where does the semilunar valve open on a PV loop?
D
Where does the semilunar valve close on a PV loop?
F
Where does the AV valve open on a PV loop?
A
Where does the AV valve close on a PV loop?
C
Release of atrial natriuretic peptide (ANP) results in increased or decreased vasopressin (ADH)?
decreased vasopressin (ADH) release
Which of the following physiological changes are seen during exercise? Select all that apply.
a. increased heart rate
b. increased contractility
c. increased total peripheral resistance
d. increased cardiac output
a. increased heart rate
b. increased contractility
d. increased cardiac output
Which of the following will not increase cerebral blood flow? Select all that apply.
a. hyperventilation
b. increased O2
c. increased CO2
d. decreased pH
a. hyperventilation
Increased O2, CO2, and [H+] increases or decreases cerebral blood flow
increases
True/False: ANP causes an increase in salt and water retention
False
ANP actually promotes renal salt and water excretion.
Is ANP released during high or low blood pressure?
high
Does ANP cause salt excretion or retention?
excretion
