PHY3171 Lecture 5: Hypertension
10 Feb 2019
School
Department
Course
Professor
15/03/18
CARDIOVASCULAR RESPONSE TO STRESS L5
HYPERTENSION
– Once you have high blood pressure, you have it for the rest of your life – can only be on
antihypertensive medication for the rest of your life
– Want to be able to find a cure or prevent it from happening altogether
COMPONENTS OF CARDIOVASCULAR CONTROL
Baroreceptors
– By removing the baroreceptors would believe that chronic hypertension would result
– BUT it doesn’t → baroreceptors = short term control of blood pressure
– Baroreceptors denervation only affects the variability of blood pressure
KIDNEY
– If BP ↑, kidney makes more urine – excretes more salt + water
– Hypertension can be caused by shifting the renal output curve OR increased salt intake
– Population salt intake predicts prevalence of hypertension
– People who did not have high BP and received kidney transplant from people with high BP
developed hypertension (and vice versa)
Salt-sensitive vs Non-salt-sensitive hypertension
– Most people have a steep pressure diuresis relation in the long term
o Can change salt intake and only small changes in arterial pressure
– Sub group have a flatter relationship
o If they went from a low to high salt intake – exaggerate increase in arterial pressure
o If they have high BP could decrease it by reducing salt intake
o BUT ALSO if they increase salt intake more susceptible to getting hypertension
Factors that can shift pressure diuresis/natriuresis relationship (to higher pressure or reduce its slope)
- Narrowing of the blood vessels leading to the kidney (aorta and renal artery)
- Salt retaining hormones (eg angiotensin II, aldosterone)
- Increased renal sympathetic nerve activity
- Renal disease
o glomerulosclerosis (damaged glomeruli)
o polycystic kidney disease
- Subtle alterations in the activity of tubular sodium transport systems
Document Summary
Once you have high blood pressure, you have it for the rest of your life can only be on. 15/03/18 antihypertensive medication for the rest of your life. Want to be able to find a cure or prevent it from happening altogether. By removing the baroreceptors would believe that chronic hypertension would result. But it doesn"t baroreceptors = short term control of blood pressure. Baroreceptors denervation only affects the variability of blood pressure. Hypertension can be caused by shifting the renal output curve or increased salt intake. Population salt intake predicts prevalence of hypertension. People who did not have high bp and received kidney transplant from people with high bp. If bp , kidney makes more urine excretes more salt + water developed hypertension (and vice versa) Most people have a steep pressure diuresis relation in the long term: can change salt intake and only small changes in arterial pressure.
