Hypertension Flashcards
What is the BP cut off for hypertension?
140 / 90
What are the 4 stages of blood pressure culminating with hypertension? What are the cut offs?
Normal - less than 120
Prehypertension - 120 -139
Stage 1 - 140 - 159
Stage 2 - 160 and up
What are the 2 types of hypertension? How are they different? Which is more prevalent?
Essential hypertension - unknown etiology - 90-95% cases
Secondary hypertension - known cause - 5 - 10 % cases
Tumors in the renal system can cause hypertension. What are 2 ways a tumor in the adrenal cortex can cause hypertension? 2 ways a tumor in the adrenal medulla can cause hypertension?
Cortex - hyperaldosteroidism, increased blood volume
Medulla - Pheochromocytoma, increased epinephrine
How can renal artery stenosis cause hypertension?
Increased renin release, increased Ang II
What is iatrogenic hypertension?
Hypertension caused by medical interventions
Neural control of the blood pressure is also know as the _. This is a [short/long] term mechanism. Sympathetic stimulation goes to _ (3). Parasympathetic stimulation goes to _ (1)
Baroreflex
Short term
Heart, vessels, kidney
Heart
What are the 3 contributors to the brain that coordinate the baroreflex?
Arterial baroreceptors
Arterial chemoreceptors
Muscle metaboreceptors
What are the 2 brainstem (medulla) regions that mediate the baroreflex?
NTS - Nucleus tractus solitarius
RVLM - Rostral ventrolateral medulla
What is the effect of the baroreflex on sympathetic NS activity? on HR, vascular tone and BP?
Decreased all of the options
How is the baroreflex thought to be altered in hypertension? (2)
Baroreceptor resetting
Labile arterial pressure
Where in the body is angiotensinogen made? Where is pro-renin and renin made? What is the source of ACE? what is another name of ACE?
Liver
Kidney
Lungs
Kininase
What enzyme converts kininogen to bradykinin? What enzyme inactivates bradykinin?
Kallikrein
Kininase II
What are 2 widely accepted endothelial derived vasodialators? What are their second messenger systems?
PGI2 - Adenylyl cyclase and cAMP
Nitric oxide - guanylyl cyclase and cGMP
What is the precursor and the enzyme that form nitric oxide? What about PGI2 (prostacyclin)?
L-arginine and nitric oxide synthase
Arachidonic acid and (cyclooxygenase and PGI2 synthase)
What are 3 widely accepted endothelial derived vasoconstrictors? What is their common second messenger?
Endothelin1, TXA2 (thromboxane) and Ang II
Calcium
What are the 2 receptors for endothelin? What does each mediate?
ETa- Constriction
ETb - Dilation
What is the precursor for thromboxane?
Arachidonic acid
What are the 2 factors that determine the contractile function of smooth muscle?
Intracellular calcium concentration
Calcium sensitivity of contractile proteins
What occurs when the myosin light chain is phosphorylated? When it is dephosphorylated? What enzyme pair mediates this “switch”?
Phosphorylated - Contraction
Dephosphorylated - Relaxation
Myosin light chain kinase and phosphotase
What is the role of the myosin light chain phosphotase? What enzyme inhibits it? What disease state is this enzyme upregulated in?
Phosphatase dephos. myosin light chain, lead to relaxation
Rho-kinase
cardiovascular disease
What is the relationship between obesity and hypertension? What is the proposed mechanism (2)?
Obese more likely to be hypertensive
- Insulin mediated sodium retention
- increased centrally mediated vasoconstriction
What are 2 way restricted sodium intake can improve hypertension?
Decreases MAP
Increases effectiveness of antihypertensive drugs
