Hypertension Themed Session

Question 1

relation between body weight, heart rate and blood pressure

Answer 1

every 10% weight gain = +6.5mmHg
when person is overweight hormone insulin leptin is released more.
this activates more neurones in the brain which activates symphatheic nervous system to restrict blood vessels to increase BP
it also increases kidney activity which increases Na+ retention

Question 2

causes of essential hypertension

Answer 2

Obesity
stress
family history of hypertension
alchol/salt intake
sedentary lifestyle

Question 3

renal physiology body weight and BP

Answer 3

increase retroperiotenal fat decreases renal blood flow
this decreases glomerulus flow rate which slows fluid movement through the nephron which means more Na+ ions is reabsorbed
this triggers macula densa

Question 4

how do ACE inhibitors lower BP

Answer 4

prevents conversion of angiotensin 1 to angiotensin 2

Question 5

hypertension treatment

Answer 5

ACE inhibitors-prevents conversion of angiotensin 1 to angiotensin 2
Renin inhibitors- block renin activity
ang2 receptor antagonists block activity of angiotensin 2
mineralocorticoid recptor antagonists- block activity of aldosterone

Question 6

hypertension treatment for black indivuals

Answer 6

more sensitive to salt and is more likely the cause of hypertension in these people
black individuals have lower levels of renin so are less responsive to anti-hypersensitive drugs
ENaC channels are more common in black people which is why they’re sensitive to salt so simple ENaC blockers help reduce BP

Question 7

why reduce salt intake to control hypertension

Answer 7

more salt leads to more water retention which increase blood volume which increases stroke volume which increases BP

Question 8

renal failure with hypertension

Answer 8

normally kidneys filter small materials into urine but reabsorb useful substances
large substances like red blood cells dont get filtered
in hypertention the filter barrier gets damaged so large substances cant get through

Question 9

levels of adrenal gland

Answer 9

cortex- zona glomerulosa, zona fasciculata, zona reticularis
medulla

Question 10

renin-angiotensin-aldosterone system (RAAS)

Answer 10

reduced sodium, blood volume and pressure sensed by either sympathetic stimulation or macular densa cells increases production of renin from juxtaglomerular cells.
which increases production of angiotensin 1 and therefore 2 which increases aldosterone which can cause further effects

Question 11

aldesterone of Na+ and water reabsorption

Answer 11

affects collecting ducts and distal convoluted tubule
aldesterone binds to mineralocorticoid recptor in membrane
this increases expression of epithelial Na channel(ENaC) which allows Na ions into cell from filtered fluid
aldesterone also causes pituitary gland to release ADH which increases expression of aquaporins which allow for more water reabsorption due to potential gradient caused by Na+ intake
the mineralocorticoid recptor also increases expression of NA-K-ATPase swapping 2K+ for 3Na+ thus increasing Na+ reabsorption

Question 12

How is BP increased by Na and water reabsorption

Answer 12

aldesterone increases Na+ and water reabsorption
this increases EDV which increases stoke volume
this increases cardiac output which increases blood pressure