PBL 6 Flashcards
how does excessive BP affect the arteries?
causes hardening of the arteries = arteriosclerosis
how does hypertension affect the IEL?
thickens it
what is retinopathy?
damage to blood vessels in retina
what is the microalbumin test and when is it used?
- tests for very small levels of proteins in the urine
- kidney failure — leak proteins and gradually fail
- this tests detects this
describe ANP
= counter-regulatory system for the RAAS
- released by cells in the atria
- responds to atrial stretch, sympathetic stimulation, angiotensin 2 (high levels)
- acts on kidney to increase glomerular filtration rate, natruiresis and diuresis — increase urinary output
- decrease renin and aldosterone release
- these all decrease blood volume, CO and BP
what is the rate limiting enzyme in RAAS?
renin
where is renin made?
kidneys
where is ACE made?
lungs
what is the receptor for covid-19?
ACE 2
why are muscular arteries the main vasoconstrictors and vasodilators?
have the most smooth muscle
what type of artery has the largest tunica media?
elastic arteries
what type of artery lacks EEL?
arterioles
how does high BP affect the kidneys?
- HBP can constrict and narrow the blood vessels throughout the body, including in the kidneys
- this narrowing reduces blood flow
- if the kidney’s blood vessels are damaged, kidneys are not able to remove all wastes and extra fluid from your body
- extra fluid in the blood vessels can raise your BP even more
- causes more damage leading to kidney failure
- kidneys become granular and shrunken, leak proteins and gradually fail
what is a good drug choice for hypertensive obese people?
obesity activates RAAS — therefore increases renal tubular Na+ reabsorption — diuretics good choice
how can alcohol lead to hypertension?
leads to increased renin and decreases baroreceptor activity
what is indapamide?
= thiazide-like drug
- diuretic (water pill)
- acts at distal tubule at NaCl channel — inhibits it
- causes increased loss of salt and water
- lowers BP
- not 1st line treatment — add on
why is it essential to monitor serum electrolyte and creatine levels during diuretic treatment?
all diuretics can disturb the plasma-electrolyte balance, especially with K+. diuretics can also cause a loss of renal function as a consequence of hypovolaemia
what is amlodipine?
- blockade of Ca++ channels
- antagonists for L-type Ca++ channels
- decreases arterial smooth muscle contractility and vasoconstriction by inhibiting the influx of Ca++ through the channels
- causes swollen ankles
name an ACE inhibitor
ramipril
what is given instead of ACE inhibitor to remove dry persistant cough?
angiotensin receptor blocker eg. candesartan
what is/describe eGFR?
eGFR = estimated glomerular filtration rate
- should be >90
- measure of kidney function
- based on age, sex, creatinine
high creatinine = low eGFR
why does oedema occur with amlodipine?
- antagonist for L-type Ca channels — decreases arterial smooth muscle contractility and vasocontriction by inhibiting the influx of calcium ions through the channels
- triggers dilation of blood vessels — lowered BP and improves blood flow
- improved flow can increase intra-capillary pressure — forces fluid into surrounding tissues
- mostly in ankles due to gravity
pre-capillary arterioles dilate more than post-capillary venules, causing hydrostatic pressure that pushes fluid out of the capillaries
what are normal levels of K+?
3.3 - 5.5 mmol/L
what are normal levels of Na+?
135-145 mmol/L
why is exercise recommended?
- increased resistance to fatigue
- decreased TPR
what is an inherited form of high BP?
liddle’s syndrome
describe liddle’s syndrome
- monogenic — Mendelian Hypertenison
- autosomal dominant
- mutations in the SCNNIB or SCNNIA gene
- Na+ is continuously reabsorbed, along with H2O
- kidneys excrete K+ but retain Na+ and H2O —> HYPERTENSION
- hypokalaemia
what is biochemical screening for nonadherance?
uses mass spec to measure levels of prescribed drugs in urine
what % of people discontinue treatment of antihypertensive drugs within 1st year?
50%
are blood vessels innervated?
yes, by sympathetic fibres only
what is the normal range for LDL:HDL cholesterol ratio in males?
<100mg/dl LDL but > 40mg/dl HDL
what part of the kidney tubule does a thiazide diuretic act upon?
distal convoluted tubule
what is the mechanism of Losaratn?
angiotensin II receptor (type AT1) antagonist
in what stage of the Stages of Change Model do people begin weighing up the pros and cons?
contemplation
which ion does bendroflumethiazide inhibit the reabsoprtion of?
Cl-
approximately what % of women aged over 75 have hypertension?
65%
what is the main social predictor of smoking initiation?
having parents that smoke
