Hypertension Flashcards
no obvious cause; risk factors include overweight, sedentary lifestyle and high salt diet
primary hypertension
increased bp due to either medical condition or medication
secondary hypertension
causes include renovascular disease, aldosteronism, pheochromocytoma
secondary hypertension
> 130 mmHg SBP OR >80 mmHg
hypertension
as we age, there is an increased risk for what
CAD (coronary artery disease)
most common form of HTN
diastolic HTN
ages 30-50
DBP elevated (above 80 mmHg)
diastolic HTN
after age of 55
systolic bp elevated (>140)
isolated systolic HTN in older adults
17-25 yrs old
overactive sympathetic NS
increased CO
isolated systolic HTN in young adults
MAP=
CO x TPR (SVR)
blood volume controlled by kidney
CO
respond to rapid change in bp (3 things)
baroreceptor reflex
chemoreceptors
CNS ischemic response
respond to longterm changes in BP and have infinite gain
kidneys
a lot of the time due to renal dysfunction
hypertension
how kidneys respond to low bp
increase fluid retention
RAS activation
vasoconstrict
when factors alter the pressure natriuresis and diuresis relationship, what happens
changes in bp will follow (HTN)
AV fistula closure ultimately causes
increase in CO and MAP
how to decrease blood volume
diuresis and natriuresis
when fistula is repaired what happens
TPR increased (venous pressure increases and pumps blood to heart)
3 main functions of kidney
glomerular filtration
tubular reabsorption
tubular secretion
net effect of the 3 stages of kidney function
what gets excreted as urine
what increases GFR (glomerular filtration rate)
vasodilation of afferent arteriole and vasoconstriction of efferent arteriole
normal natriuresis steep curve remains the same regardless of what intake (BP remains normal)
increased salt intake
what happens when you decrease filtering capacity of kidney
bp becomes salt sensitive
what happens when you elevate pre-glomerular resistance
GFR decreases and BP is elevated
what happens to MAP if renal mass is decreased
nothing
if you eat salt w/ impaired kidney filtration
bp changes (salt-sensitive)
due to decreased NO and impaired vasodilation
endothelial dysfunction
what happens in endothelial dysfunction
stop making NO, and start making ROS (vasoconstrictors)
what happens as a response to endothelial dysfunction
vascular remodeling
what happens as an effect of vascular remodeling
decrease in arterial radius
increase in resistance
increase in bp
cross sectional wall area has no change; just decreased lumen size
eutrophic
increased in cross sectional wall area and decreased lumen size
hypertrophic
3 factors leading to SNS overactivity
- deactivation of baroreceptors
- increase in activation of stimulatory inputs
- circulating Ang II
targets of SNS activity in HTN
arterial tone
adrenal medulla
RAS
most powerful system for regulating bp and body fluid volume
Renin-Angiotensin-Aldosterone system
powerful vasoconstrictor and stimulates production of aldosterone
Angiotensin II
renal baroreceptors
juxtaglomerular cells in afferent arterioles
what is released by JG cells to increase pressure
renin