Hypertension Flashcards
Why is hypertension dangerous?
predisposes to coronary disease/atheroma, cardiac hypertrophy, heart failure, cerebrovascular disease, aortic dissection and renal failure
What part of an artery can contract/relax?
the media
this can increase or decrease your blood pressure
what is essential/primary hypertension?
cases of hypertension with no specific identifiable cause
how does renin-angiotensin system influence blood pressure?
renin (from juxtoglomerular aparatus) converts plasma angiotensinogen which is then converted to AT2 by angiotensin converting enzyme (ACE)
this acts on the arteriolar smooth muscle to constrict them
and stimulate secretion of adrenal mineralocorticoid aldosterone to retain sodium and maintain blood volume
What are our main mechanisms for treating hypertension?
ACE inhibitors
Diuretics
Vasodilators
What are the main causes of secondary hypertension?
main causes are
- renal
- adrenal
- other endocrine
- miscellaneous
how does a renal failure cause hypertension?
stenosis of the renal system, vasculitis, renin producing tumours etc. can trick the RAAS system into increasing blood pressure
how does your adrenal gland cause hypertenison?
- iatrogenic cushing is very common (caused by medical treatment)
- cushings = over use of glucocorticoids - can happen if a carcinoma of the adrenal cortex
What is Cushings syndrome?
- obese with round face due to steroid effect
- acne
- adrenal adenoma (yellow adenomas b/c it’s a very fatty organ- steroids are based on cholesterol)
What is Conn’s Syndrome ?
Where you have an adrenal tumour that pumps out aldosterone - just has a mineralocorticoid effect
so you don’t get the moon face like cushings - you DO get the hypertension though
What is a Pheochromocytoma?
rare tumour of the medulla
classically paroxysmal hypertension
(looks a lot like anxiety)
Reddish brown like tumour
What are some endocrine reasons for hypertension?
- Thyroid hypo/hyper
- pituitary tumour producing growth hormone
- cushing disease - pituitary tuour
- pre-eclampsia - plasma renin production
what are the cardiac consequences of hypertension?
it accelerates atheroma fomraiton
-initially there are hypertrophic changes involving the medial smooth muscle and increased elastic tissue in large arteires
later, it leads to fibrous change and loss of elastic tissue - aortic dissection/haemorrhage, rupture of cerebral berry aneurysms
how does hypertension effect small arteries and arterioles?
thickening of walls of these vessels, luminal narrowing especially in the kidney, chronic renal impairment
With severe uncontrolled hypertension - necrotizing change “fibrinoid necrosis” in small vessels may lead to acute renal failure - It’s called “malignant hypertension” just to get across the aggressiveness of it (not b/c it’s cancerous)
