Long-term Control BP Hypertension - IN

Question 1

what is the set point for BP (generally)

Answer 1

hypotension would be systolic under 90, and hypertension would be systolic over 140, but everyone has their own normal set point

Question 2

what can make BP vary

Answer 2

age, time of day, stress, fever, exertion

Question 3

what is the equation for BP

Answer 3

CO x PVR

Question 4

what are the main factors influencing BP

Answer 4

cardiac output, peripheral resistance and blood volume

Question 5

what is the fast factor that controls BP

Answer 5

baroreceptor reflex

Question 6

what is the intermediate factor that controls BP

Answer 6

renal actions, causing changes in PVR

Question 7

what is the slow factor that controls BP

Answer 7

renal salt and water excretion, mainly handled by Angiotensin II

Question 8

whats the primary purpose of the juxtaglomerular apparatus

Answer 8

to help control BP

Question 9

what does the macula densa do

Answer 9

senses changes in osmolarity, Cl-

Question 10

what do juxtaglomerular granular cells do

Answer 10

produce renin

Question 11

what does a decline in BP cause

Answer 11

release of renin, which leads to release of AII, which stimulates ADH, which increases water reabsorption

Question 12

what does aldosterone do

Answer 12

stimulates proximal Na-H exchange, increasing Na/water reabsorption, and kicking out K. Decreases urine volume and increases BP/volume.

Question 13

what causes an increase in Na reabsorption

Answer 13

cortisol, estrogen, GH, TH and insulin

Question 14

how do primary hyperaldosteronism patients present

Answer 14

very low potassium and hypertension

Question 15

what are the determinants of renin secretion

Answer 15

neural baroreceptors signal via renal sympathetics to granular cells
stretch receptors within afferent arterioles, which can function without innervation
NaCl delivery to macula densa, osmotic swelling releases transmitter to inhibit renin secretion

Question 16

what does tubuloglomerular feedback accomplish

Answer 16

afferent arteriole constricts when confronted with too high GFR, putting break on the process.

Question 17

lets talk about CHF v COPD

Answer 17

those with CHF will have high BNP b/c their blood volume is increased (BNP is a naturetic peptide involved with inhibited renin and relaxing afferent arteriole; leads to diuresis). In pt with GI bleeds, antidiuretic hormones can be given to increase water resorption and inc blood pressure (since it will vasoconstrict blood vessels).

Question 18

what controls water excretion, and where

Answer 18

ADH in the distal nephron

Question 19

what does the proximal nephron regulate

Answer 19

ECF

Question 20

how does the proximal nepron regulate ECF

Answer 20

BP - if it falls, ADH increases to increase water resorption, increasing total body water and blood volume

Question 21

what happens when you eat too much salt

Answer 21

osmolarity increases, fluid is expanded, therefore you decrease ADH to decrease water resorption and urinate more to try and balance it, reducing volume, TBW