Hypertension Flashcards
(24 cards)
What is the equation for cardiac output?
CO= HR X SV
What is the equation for blood pressure
BP= HR X SV X TPR or
BP= CO X TPR
How is vascular smooth muscle controlled?
- Receptors on Vascular smooth muscle e.g adrenoreceptors
- Receptors on Endothelial cell
E.g receptors for acetycholine
What are a1-adrenoreceptors
- they are activated by noradrenaline and adrenaline (catecholamines)
-causes vasoconstriction
-causes increased resistance
What do a1-adrenoreceptor antagonists do?
Reduce resistance therefore used as antihypertensives
What are b2- adrenoreceptors
Less influence on total resistance
Activation causes relaxation and decreased resistance
How do b2- adrenoreceptor antagonists work? (beta blockers)
Increase resistance therefore they are hypertensive agents
What do calcium channel blockers do
Bind to the L
type channel restricting calcium from entering
What do ace inhibitors do
Block the conversion of angiotensin I to angiotensin II. They also inhibit bradykinin levels (peptide that causes vessels to dilate by stimulating nitric oxide and prostacyclin)
What do ARBS do
They block the angiotensin receptor which is also responsible for producing aldosterone so water and sodium retention
What do renin lnhibitors do
Block the conversion of angiotensinogen to angiotensin I . Therefore inhibiting the production of Angiotensin II
How is BP regulated
BP is regulated by baroreceptors on the carotid sinuses. So when BP is too low the baroreceptors send signals to the adrenal medulla triggering an increase in the sympathetic system through activation of b1 and alpha1 receptors
What do centrally acting adrenergic drugs do (clonedine and methyldopa)
Activate the alpha 2 receptors. Causing negative feedback to reduce catecholamine production and therefore reduction in BP
What’s the difference between dihydropyridine and nondihydropyridine calcium channel blockers
Dihydropyridines only work on L type channels on smooth muscles whereas NDH works on smooth muscle, cardiac cells , SA and AV node 🤣🤣
How do loop diuretics (furosemide)work
Reduce the absorption of sodium chloride in the loop of henle. Leads to diuresis. So less volume in the vascular space means less blood returns to the heart. So BP decreases
How do thiazide diuretics work (hydrochlorothiazide)
Reduce reabsorption of NaCl in the DCT
What are the two mechanism of potassium sparing diuretics work
- Interfere with sodium potassium exchange
- Blocking the actions of aldosterone
How do non selective beta blockers works?
Bind to alpha and beta receptors. So simultaneously decrease vascular resistance and cardiac output
Types of non selective beta blockers
Labetalol
Carvedilol
How do selective beta blockers work
Bind to beta1 receptors on the heart decreasing cardiac output
What are the types of selective beta blockers
Atenolol
Metoprolol
Name types of dihydropyridines
Amlodipine
Felodipine
Nicardipene
Nifedipine
Name Non dihydropyridines
Diltazem
Verapamil
what to do if white coat is suspected during a review
consider abpm or hbpm as they are in the comfort of their home
