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Flashcards in Hypertension Deck (29):
1

Systolic Blood Pressure

(SBP) avgs 120 mmHg

2

Diastolic Blood Pressure

(DBP) avgs 80 mmHg

3

Mean Arterial Pressure

(MAP) avg pressure responsible for driving blood forward to the tissues
MAP = DBP + (1/3)PP
where PP = SBP - DBP

4

Pulse Pressure

PP = SBP - DBP

5

Which pressure does the body seek to regulate?

MAP!! not diastolic or systolic

6

Definition Hypertension

BP greater than or equal to 140/90 mmHg on 2 or more BP readings from 2 or more visits

7

Types of Hypertension

1. Primary (multi-factoral, 95% of cases)
2. Secondary (single known cause, 5% of cases)

8

Risk Factors

1. Salt rich diet
2. Diabetes, Dyslipidemia
3. Alcohol
4. Genetics
5. Sedentary lifestyle
6. Obesity
7. Smoking/Tobacco

9

Age and Hypertension

Age is related to aortic stiffness, this leads to inc SBP and decreased DBP which means higher PP which in turn means increased MAP

10

Clinical Presentation

Usually without symptoms :/
those which do present are typically headache, fatigue, which are not unique to hypertension

11

Ohm's Law

Delta P = Flow x R

12

Ohm's Law in the Body

MAP = Cardiac Output (CO) x Total Peripheral Resistance (TPR)

13

Relation Radius to TPR and MAP

Inversely Proportional: as R dec the TPR and MAP increase

14

Baroreceptors of the Heart

exert major control of ANS w/ respect to MAP
nerve endings in arterial wall which respond to stretch
send signals which indicate to the brain how to adjust para and sympathetic tone
ALLOWS IMMEDIATE SHORT TERM CONTROL OF THE BP

15

Stimulation of Baroreceptors

Beta 1 in Heart = inc HR, inc SV, inc BP
Alpha 1 = vasoconstriction arterioles, inc BP
Beta 2 = vasodilation arterioles, dec BP

NEUROTRANSMITTER = norepinephrine

16

Pheochromocytomas

Adrenal Tumor; secretes excessive amounts of norepinephrine

17

Obstructive Sleep Apnea (OSA)

Frequently stop breathing during sleep; frequent hypoxic episodes lead to hyper-adrenergic state; inc BP

18

Chronic Stress

Higher Adrenergic State, leads to inc BP

19

Vasculature

Aorta is elastic, gets less so w/ age
Arterioles = resistance vessels (have a thick layer of smooth muscle around them)

20

Vasoconstrictors

endothelin
angiotensin II (AT2)
vasopressin
thromboxane
neurotransmitters

21

Vasodilators

nitric oxide
bradykinin
prostacyclin

22

Consequence of Prolonged Vasoconstriction

Increased afterload, this is more work for the heart

23

Consequences Inc Pressure in the Vasculature

endothelial damage --> atherosclerosis
weakening of the vessel walls

24

RAAS --> Kidney BP Regulation

baroreceptor sensing device in the arterioles leading to the kidneys, when pressure to the kidney is low they release RENIN

25

Renin Cycle

1. RAAS detects dec BP
2. Releases Renin
3. Renin converts angiotensin to angiotension I (AT1)
4. ACE turns AT1 into angiotensin II (AT2)
5. AT2 causes vasoconstriction
6. AT2 also causes release of norepinephrine and Aldosterone

26

Aldosterone and Blood Pressure

Inc Na and H2O reabsorption
Inc blood volume
inc stroke volume
inc cardiac output
inc blood pressure

27

Stroke Volume

Blood Volume

28

Cardiac Output

CO = Heart Rate x Stroke Volume

29

Renal Artery Stenosis

Narrowing of the renal artery, dec renal function, activation of RAAS which restores the lowered pressure in the intraglomular area but also inc BP