Blood Pressure Regulation and Hypertension

Question 1

rate of blood flow through the lungs and why

Answer 1

pulmonary blood flow constitutes the entire right ventricle. PBF is equal to the entire right ventricle volume of 5 L/min

Question 2

what control mechanisms regulate blood flow to organ or tissue capillary beds

Answer 2

intrinsic control: within that tissue, sympathetic blood flow into caps, auto regulated

extrinsic blood flow SNS hormones

Question 3

intrinsic- metabolic theory of auto regulation

Answer 3

as local tissue metabolism increases due to increased activity, local factors are produced by the tissue that dilates arterioles that perfuse the tissue resulting in increased blood flow to that tissue. it decreases resistance

O2 and nutrient supply to tissues increases as long as metabolism is increased

Question 4

O2 decrease

Answer 4

cell metabolism

Question 5

CO2 increase

Answer 5

cell metabolism

Question 6

H increase pH decrease

Answer 6

cell metabolism

Question 7

K+ increase

Answer 7

cell metabolism

Question 8

adenosine

Answer 8

ATP breakdown

Question 9

Histamine

Answer 9

mast cells

Question 10

Nitric Oxide (NO2)

Answer 10

endothelium

Question 11

Prostacyclin (PGI2)

Answer 11

endothelium

Question 12

myogenic theory of autoregulation

Answer 12

myogenic- contraction originates in the muscle. true of cardiac and smooth muscle. Ca2+ stretch-activated smooth muscles open when pressure or force distends the cell membrane allowing the muscle to contract in response to stretch - increased perfusion pressure, increase VGCC, increased vasoconstriction, decreased flow - negative feedback

Question 13

extrinsic blood flow (outside, not local) controls

Answer 13

ANS and Hormones/Neurohormones

Question 14

which branch of ANS has control of blood vessel tone

Answer 14

sympathetic

Question 15

alpha 1 receptor

Answer 15

NE, some EPI, constricts

Question 16

Beta 2

Answer 16

epi only, dialates

Question 17

muscurinic receptors

Answer 17

controls the bladder, cold medication may cause bladder relaxation

Question 18

angiotensin regulates blood volume and blood flow

Answer 18

regulation of aldosterone release from adrenal cortex (inc Na+ reabsorption)
regulation of vasopressin release from hypothalamus (anti-diuretic)
increased SNS activity - increased vasopressin (antidiuretic), increases thirst, increases CV response, increases Na+ reabsorption
direct vasoconstriction

Question 19

effects of angiotensin 2 synthesis inhibitors or receptor blockade

Answer 19

reduction of SNS activity from CV control center in Medulla Oblongata
reduction in vasopressin release from posterior pituitary
- decreased H2O reabsorption in kidney decreased blood volume
- reduction of aldosterone synthesis - decrease Na+ reabsorption in kidney - decreased blood volume
- reduce direct vasoconstriction

Question 20

epinephrine

Answer 20

produced in response to SNS activation and released from adrenal medulla - allows vessels to dilate while others will constrict ( alpha constricts and beta dialates)

Question 21

regulation of mean arterial pressure

Answer 21

arterial pressure- driving pressure created by the pumping of the heart. when we measure the brachial artery its an estimate of the total pressure created by ventricular contraction. abnormally high or low blood pressure can be indicative of a problem in the CV.

Question 22

MAP =

Answer 22

Diastolic Pressure + 1/3 Pulse Pressure

Question 23

Pulse Pressure =

Answer 23

systolic - diastolic

Question 24

factors that affect MAP - Blood Volume

Answer 24

drug: diuretics

determined by fluid intake or fluid loss (passive or regulated at kidneys)

Question 25

describe baroreceptor response to either a rapid drop or increase in blood pressure

Answer 25

control of HR and MAP stretch receptors in aorta or carotid relay information to the CV control center. the afferent nerves from the baroreceptors fire faster with increased pressure, slower with decreased pressure - aortic pressure inc, inc firing rate CV control center in medulla oblongata- 1. dec symp output (alpha 1 receptor (dilate arteriole, dec peripheral resistance), b1 receptor (dec force of contraction on ventricular myocarium dec CO), B2 (SA node, dec heart rate, dec CO) 2. inc para symp- inc more ACh on muscurinic receptor- SA node, dec heart rate- dec CO

Question 26

Preventable risk factors

Answer 26

smoking (nicotinic receptor: ligand gated dec heart rate, chronic use elevates pressure), untreated hypertension, diabetes, obesity, dylipidemia, sedentary lifestyle, atheroclerosis (inc lipid levels)

Question 27

describe criteria for stage 1 and stage 2 hypertension. when should pharmacological treatment be initiated

Answer 27

stage 1 pressure: 130-139 stage 2 pressure: above 140 treatment of BP should begin at stage 2. the goal, even those with diabetes, should be between <130/80, patients over 80 years should have <150 systolic

Question 28

primary hypertension

Answer 28

unknown origin 90% of all hypertension multiple gene involvement common theory: baroreceptors reset at higher levels

Question 29

compensation for increase blood flow

Answer 29

compensation by CV system- vasodilation, CO goes down (fast response)mediated by baroreceptor reflex compensation by kidneys- excretion of fluid in urine decreases blood volume (slow response)

Question 30

tissue/organ effects of uncontrolled hypertension

Answer 30

1. vascular tissue: acceleration of atherosclerosis, rupture of aortic aneurysms, peripheral arterial disease, erectile dysfunction 2. heart: increase IM risk, cardiac hypertrophy, angina 3. kidney: renal failure, proteniuria, increase BUN 4. eyes: retinopathy and blindness 5. brain: hemorrhagic or ischemic stroke, reduced cognition, aneurysm

Question 31

unpreventable risk factors

Answer 31

age, gender, risk, family history higher in younger men, older women, African Americans older women more at risk because of menopause AA> hispanic > Caucasian

Question 32

secondary hypertension cause!

Answer 32

cause is known: 1. renal disease (renal artery stenosis 2. endocrine disorders: hyperthyroidism 3. vascular disorders- atherosclerosis, coarctation(smaller in diameter of the aorta) 4. neurologic disorders- brain tumors, spinal cord injuries 5. tobacco use 6. medications or illicit drug abuse- cocaine, amphetamines/stimulants (ritalin, ADHD meds), cold meds (pseudoephedrine), diet pills: ephedrine, sibutramine

Question 33

treatments for primary hypertension

Answer 33

life style modification, pharmacotherapy, diet, exercise, sodium restriction, beta blockers, direct vasodialators, alpha1 adrenergic antagonists, alpha2 adrenergic agonists, thiazide diuretic, angiotensin 2 synthesis or receptor blockers, calcium channel blockers