PPT 11: antihypertension Flashcards
What is the equation to calculate MAP
DBP+1/3(SBP-DBP)
What are factors that affect blood pressure?
peripheral resistance
vessel elasticity
blood volume
cardiac output
What is the Hydraulic equation
BP=CO x PVR
What are the 3 main sources of peripheral resistance?
blood vessel diameter
Blood viscosity
total vessel length (overweight ppl have inc. # of vessels)
where are baroreceptors located?
carotid arteries
aortic arch
How do the kidneys attempt to fix hypotension?
RAA cascade: hypotension in renal arterioles stimulates renin production. Renin -> angiotensin 1 -> angiotensin 2
angiotensin 2 causes vasoconstriction, stimulates aldosterone (inc. sodium absorption, intravascular volume)
What are the 4 types of antihypertensive agents?
diuretics
sympathoplegics (a2 agonists)
direct vasodilators
anti-angiotensins
Why is methyldopa better than clonidine for pregnant women?
Doesn’t cross the placental barrier like clonidine does
used for 2nd and 3rd trimester HTN
BP maintained by regulating:
- cardiac output (systolic)
- peripheral vascular resistance (diastolic)
What is systolic pressure? What is the normal range?
peak arterial pressure (120 mmHg)
What is diastolic pressure? What is the normal range?
lowest arterial pressure (70 - 80 mm Hg)
______ propels the blood to the tissues
MAP
What are the causes of primary hypertension?
- CV disease - most common
- obesity, age (over 40), diabetes, heredity, stress, smoking, renal failure, CV disease, stroke
Differentiate between the stages of hypertension
Normal - 120/80
Prehypertension (between)
Hypertension 140/90
Stage 1 (between)
Stage 2 - 160/100
What is driving venous pressure?
back pressure driving venous tone
skeletal muscle squeezes veins
one way valves
What are the four anatomic sites of BP control?
- Resistance - arterioles
- capacitance - venules
- pump output - heart
- volume - kidneys
