Blood Pressure Regulation

Question 1

what are 4 determinant of blood pressure

Answer 1

Blood volume
overall compliance
cardiac output
peripheral resistance

Question 2

An increase in blood volume cause what effect on blood pressure

Answer 2

increase in BP

Question 3

An increase in blood vessel elasticity (compliance) cause what effect on blood pressure

Answer 3

decrease in BP

Question 4

An increase in cardiac output cause what effect on blood pressure

Answer 4

increase in BP

Question 5

An increase in peripheral resistance cause what effect on blood pressure

Answer 5

increase in BP

Question 6

Blood pressure is regulated short term by what mechanism

Answer 6

contriction/dilation

Question 7

Describe the baroreceptor reflex pathway

Answer 7

Sensors detect change in AP → afferent neurons → brain stem ctrs coordinate response by the ANS outflow via efferent nerves and create a desired change in heart and blood vessels.

Question 8

As part of the broreceptor reflex, the sympathetic nervous system innervates all vasculature except

Answer 8

capillaries, precap. sphincters and metarterioles

Question 9

The aortic baroreceptor is associated with which nerve

Answer 9

vagus nerve

Question 10

The carotid baroreceptor is associated with which nerve

Answer 10

glossopharyngeal via Hering’s nerve

Question 11

The medial portion of the vasomotor center to control BP control via which fibers

Answer 11

Dorsal nulcei of vagus nerve

Question 12

The lateral portion of the vasomotor center to control BP control via which fibers

Answer 12

Sympathetic fibers

Question 13

Neurons within which brain structure excites and inhibits the vasomotor center for BP

Answer 13

Reticular substance of the Pons, mesencephalonand diencephalon

Question 14

Neurons within which brain structure MILDLY excites or inhibits the vasomotor center for BP

Answer 14

Hypothalamus posterolateral region neurons

Question 15

Neurons within which brain structure increases or decreases activity of the vasomotor center for BP

Answer 15

Cerebral cortex: temporal lobe, orbital, cingulate gyrus, amygdala, septum and hippocampus

Question 16

Which neurotransmitter dilates vessels when binding to β-adrenergic receptors

Answer 16

Epinephrine

Question 17

Which test is used to asses orthostatic intolerance cause by sympathetic nervous system dysfunction

Answer 17

Head up tilt table test

Question 18

what is expected to happen in a head up tilt table test

Answer 18

HR and BP changes

Question 19

What is the stimulus in a head up tilt table test

Answer 19

decreased central blood volume due to pooling of blood in the legs

Question 20

A test for baroreceptor functionality

Answer 20

Valsalva maneuver

Question 21

How do you calculate the magnitude of the reflex bradycardia

Answer 21

ΔHR/ΔBP

Question 22

Which response is considered very powerful activator of sympathetic vasoconstrictor system

Answer 22

CNS ischemic response

Question 23

Apart form the baroreceptor reflexes, what are other reflexes for BP

Answer 23

CNS ischemic response
Cushing reaction (a type of CNS ischemic response)
 Atrial stretch 
bainbridge reflex
Abdominal compression reflex

Question 24

How does a Cushing reaction occur to maintain BP

Answer 24

When CSF > AP This compresses arteries in the brain (↓ blood to the brain). Art. Pr. ↑ → Art. Pr. > CSF pr. Restores BF to the brain.

Question 25

How does an atrial stretch occur to maintain BP

Answer 25

due to ↑ Blood Volume → 1. dilates afferent arterioles of the kidneys (↑ GFR) 2. and ↓ release of (ADH), leading to ↓ water reabsorption and ↑ fluid loss

Question 26

How does a bainbridge reflex occur to maintain BP

Answer 26

Atrial stretch send signals via the vagus to the medulla, in turn efferent signals are send to the heart leading to ↑ inotropy and chronotropy

Question 27

The bainbridge reflex prevents what

Answer 27

prevents blood from damming in atria, veins and pulmonary circulation

Question 28

Which reflex to maintain BP is important in spinal cord injury

Answer 28

Abdominal compression reflex

Question 29

How does a abdominal compression reflex occur to maintain BP

Answer 29

Vasoconstriction of abdominal vasculature due to abdominal muscle contraction translocates blood to the heart increasing Q

Question 30

What happens in Emotional fainting (Vasovagal syncope)

Answer 30

Thoughts or sensations in the cerebral cortex → vasodilatory ctr. of the ant. Hypothalamus → vagal ctr. of the medulla → heart and through the vasodilator nerves of muscles → ↓ HR and massive vasodilation

Question 31

What chemicals are chemoreceptors for BP sensitive to

Answer 31

↓O2 , ↑ CO2, & ↑ H+ due to ↓ blood perfusion. Stimulated when art. Pr. < 80 mm Hg

Question 32

Renal-Body Fluid System and Arterial Pressure Control is what kind of feed back? an increase in pressure causes what?

Answer 32

Negative feedback ↑ Pr. →↑ diuresis and natriuresis

Question 33

In a healthy kidney, chronic increased salt intake (6x N) causes __________ (big/small) changes in Art. Pr. .

Answer 33

Small changes

Question 34

Acute increase in salt intake causes larger shifts in the arterial because of what

Answer 34

↓ antinatriuretic systems (↓ SNS act. and ↓ AII and Aldosterone)

Question 35

What is RENIN-ANGIOTENSIN’S ROLE IN ARTERIAL PRESSURE CONTROL

Answer 35

It increases arterial pressure by vasoconstriction and renal retention of salt and water