Lecture 17/18 ish Flashcards
what is the mitral valve between
the left atrium and left ventricle (mitral valve = bicuspid)
what is the AV valve between
the aorta and left ventricle
what happens in mitral valve regurgitation
failure of mitral valve to close properly during systole results in backflow from the left ventricle into the left atria
- systolic murmur
- increased pressure in the LA causes increased pulmonary venous pressure which leads to pulmonary edema
what happens during AV valve regurgitation
aortic valve doesn’t close properly during diastole so blood flows back into the left ventricle from the aorta
-diastolic murmur
what happens to pulse pressure if there is a decrease in compliance
pulse pressure will increase
decreased compliance = vessels are stiffer
what happens to the pulse pressure in a patient with PDA
it would increase b/c there is lower diastolic pressure and higher systolic pressure
hormone released when atrial stretch is reduced
- enhances water reabsorption in renal tubules &
- vasoconstricts peripheral resistance vessels
ADH (anti-diuretic hormone)
what hormones result in an increased retention of fluids
renin
aldosterone
angiotensin II
ADH
what is VSD
ventricular septum defect = hole in interventricular septum
- during systole, blood flows from the left ventricle into the right ventricle
- The right ventricle gets close to the same pressure as LV (since its getting blood from both the right atrium and LV) which elevates pulmonary artery pressure and flow
-RV hypertrophy and mild LV hypertrophy
-systolic murmur
explain PDA
what type of murmur
what happens
continuous murmur b/c
- during systole, aortic pressure is much higher than the pressure in the pulmonary artery so blood flows from the aorta to the pulmonary artery (backwards)
-during diastole, the aortic pressure remains higher than the pulmonary artery pressure thus maintaining the murmur
what happens to the EDV in VSD
EDV increases b/c there is an increased volume of blood in the ventricles
what happens to the ESV in VSD
ESV increases due to the increased volume of blood still remaining in ventricles after systole
what happens to SV in VSD
SV decreases as hypertrophy and an increased afterload makes it harder for the ventricles to pump out the blood volume
explain the atrial receptor reflex and what happens when it is active vs less active
atrial receptor reflex are stretch receptors in the L&R atria and pulmonary veins that respond to changes in volume
an increased volume in the atria activates the receptors (increases rate of APs)
—> ANP release
—- vasodilates and inhibits renin
a decreased volume in atria would reduce the rate of APs at the receptors
—> ADH release which stimulates renin release
—> increased thirst
what things affect TPR
local controls (O2, CO2, pH)
arteriolar radius
blood viscosity
blood vessel length
explain what happens during the defense alarm reaction
baroreceptor reflex undergoes a change in setpoint in order to maintain a high BP
increased sympathetic (NE, EPi release)
release of Angiotensin II and ADH
increased BP, SV, HR
vasoconstriction of non-critical organs
vasodilation of coronary vessels and working muscle
what is the CV systems response to exercise?
the increased demand for O2 and CO2 removal is met by an increased CO and redirection of blood flow
hormone released when plasma osmolarity or blood pressure is low that causes arteriolar vasoconstriction and increases the reabsorption of water in the kidneys
ADH/AVP (vasopressin)
what is the effect of epinephrine on B2 adrenergic receptors?
causes the relaxation of smooth muscle at arterioles and skeletal muscle
what hormone would be released in a hypovolemic state (fluid loss)
ADH
- increases kidney ability to reabsorb water
- causes vasoconstriction
what hormone(s) would be released in a hypervolemic state (excess fluid)
ANP
- targets kidneys to decrease Na+ reabsorption
- promotes vasodilation
- inhibits renin release
explain the effect of dehydration on arterial pressure
decreased CO b/c preload decreases which decreases SV
TRP increases b/c the rest of the arterioles constrict to minimize fall in arterial pressure and divert blood to essential organs
what would the effect of reduced contractility have on ESV and systolic ventricular pressure
both would increase
explain the cause of fluid retention and peripheral edema / pulmonary congestion in heart failure
reduced blood flow during heart failure activates neurohormonal systems (renin, angiotensin II, aldosterone, ADH) which cause fluid retention
increased capillary hydrostatic pressure favors filtration which causes pulmonary congestion and peripheral edema
