Complete Solutions
Decreased coupling with adenylyl cyclase may be due to down regulation secondary to an
increase in circulating catecholamines with age. Why does the responsiveness of β-
adrenergeic receptors decrease with age?
The left ventricular wall thickens, but myocytes numbers do not increase. This means just
thickening and not extra muscle for stronger pumping. Why effect does the increase in
afterload have on the heart with age?
The intima thickens and microvascular deformities form. What structural changes occur
in the vasculature that lead to arteriosclerosis?
Ventricular filling pressures: Increase
Afterload: Increase
Contractility: Decrease What happens to each of the following with age: [Increase,
decrease, or no change]
,Ventricular filling pressures
Afterload
Contractility
Arteriosclerosis leads to INCREASED vascular resistance and DECREASED perfusion pressure.
Arteriosclerosis leads to [increased/decreased] vascular resistance and [increased
decreased] perfusion pressure.
With age, arteries begin to stiff (decrease in compliance) due to a decrease in elastin production.
This leads to an increase in SBP and a decrease in DBP which widens pulse pressure (SBP-
DBP).
Further explanation:
The "reflection" wave from the aorta typically is "absorbed" by the arteries and reflected back
slowly where it is shown as the diacrotic notch in a healthy, young individual.
With loss of compliance, the wave is reflected back quickly (no "absorption") and the notch is
lost in the systolic wave, augmenting it. It amplifies systole, making it higher, thus creating a
,larger discrepancy between systole and diastole. Why does pulse pressure widen as we
age?
Less With age, is more or less O₂ consumed by the CV system?
Drugs will have a greater than expected plasma concentration when injected due to less volume
to "dilute" the into. Blood volume decreases 20-30% as we age. Why is this significant?
LVEDV ↑
SVR ↑
CO ↓
Contractility ↓
PA ↑
PVR ↑
Resting HR ↓ What happens to each of the following CV parameters as we age:
LVEDV
SVR
, CO
Contractility
PA
PVR
Resting HR
Due to a decrease in conduction fiber density and the number of sinus node cells. When
experiencing hypoxia, hypovolemia, or hypotension, a typical compensatory mechanism is to
increase HR. However, elderly patients are less able to compensate with increased HR. Why?
Thickened aortic valve cusps → aortic stenosis. These patients have a "fixed" CO and cannot
compensate well. Must aggressively treat HoTN. Thickening of the aortic valve cusps can
occur with age. Why is this significant in the face of HoTN?
Decreased CNS activity with age. Why is the respiratory response to things such as
hypercapnia or hypoxia impaired with age?