38 Hypertension Flashcards
What is hypertension level? symptomatic or asymptomatic?
sustained 140/90 mmHg, asymptomatic
What is the JNC7 classification of hypertension for Normal? Prehypertension? Stage1? Stage2?
High= 160 or >100
Do systolic or diastolic BP tend to decrease after 50 years old?
Diastolic–systolic seems to just keep increasing
What is 90-95 % of all hypertension and has an unknown etiology? What does the unknown etiology arise from?
- Essential hypertension
2. Polygenetics and altered regulation of arterial pressure
How does a tumor of the adrenal cortex cause hypertension? Adrenal medulla?
- increase mineral corticoids–> increase blood volume
2. increase epinephrine–> vasoconstriction
What does renal artery stenosis do to cause hypertension?
Increase renin release–increase angiotensin II Also other kidney will eventually hold off its higher volume because of TGF
What is the definition of MAP?
Cardiac output x total peripheral resistance
What are the 2 major determinants of stroke volume?
Ventricular filling pressure and myocardial contractility
What is the most important neural sensory mechanism for blood pressure?
Arterial baroreceptors (also chemoreceptors and muscle metaboreceptrs
What are the two main outputs from neural control on BP?
ParaSNA=Heart
Sympathetics= heart vessels and kidney
What is the neuronal route from the carotid sinus to the SNA input to the kidney?
carotid sinus–>NTS—>RVLM–>SNA IML etc.
What are the 2 underlying causes of abnormal baroreceptor function?
loss of afferent function=oxygen radicals, atherosclerosis, less distensible
central defect= angiotensin II, loss of baroreceptor pathways, emotional or reactive stress
What does normal fluid regulation look like in the kidney?
up arterial pressure–> up renal perfusion–> down Na and H2O reabsorption and down renin release
What percentages of people have high, low and normal renin but have hypertension?
15% high, 25% low, 60% normal, but drugs attacking the renin are still very effective
Vasopressin, aldosterone, catecholamines have what general effect on BP?
Increase CO and peripheral vascular resistance
What does angiotensin II feedback inhibit?
Renin- at renal B1 receptors [blocks angiotensinogen from becoming angiotensin II]
Which angiotensin II receptor leads to increased aldosterone? Is this a slow or fast pressor response?
AT1 [this is a slow pressor response]
How does ACE inhibitor modulate the bradykinin system?
Blocks kininase II from degraded bradykinin which leads to B2 effects of vasodilation and B1 effects of inflammation
What are the 3 endothelial-derived vasodilators? how do each lead to vasodilation
- PGI2- up adenylyl cyclase–>incr. cAMP–>SM relax
- NO- up guanylyl cyclase–> incr. cGMP–> SM relax
- EDHF–> k channels and SM hyperpolarization effect
Does abnormal vascular function in CV disease arise from abnormal endothelial function or abnormal smooth muscle function?
Both
What is smooth muscle function determined by?
Intracellular calcium concentration and calcium sensitivity of contractile proteins
What are the 3 endothelial-derived vasoconstrictors? What happens in the smooth muscle cell?
- endothelin-1
TXA2
AngII - Increase Ca2 concentration
Does NE cause vasodilation?
Vasoconstriction
Does endothelin-1 on ETa or ETb lead to constriction?
ETa…ETb does dilation
