Cardiovascular Reflexes

Question 1

Where are Baroreceptors located?

Answer 1

Carotid Sinus!!!!

And minimally in aortic arch.

Question 2

With decreased arterial pressure, is there decreased or increased baroreceptor firing?
Increased arterial blood pressure?

Answer 2

Decreased blood pressure=decreased baroreceptor firing.

Increased blood pressure=increased baroreceptor firing.

Question 3

What is activated when there is decrease baroreceptor firing?

Answer 3

Increase Sympathetic innervation to increase Cardiac Output and SVR.
And decreased parasympathetic firing.

Question 4

What change do baroreceptors sense?

Answer 4

Changes in blood pressure in the carotid sinus.

Question 5

Does the baroreceptor reflex have more effect on rapidly changing BP or long term BP changes?

Answer 5

Rapidly changing pressure. especially postural changes in BP.

Question 6

What is the Bainbridge Reflex?

Answer 6

Infusion of volume causes an increase in heart rate due to activation of atrial stretch receptors which causes medullary center activation of sympathetic output to the SA node.

Question 7

How does degree and direction of HR change depend on prevailing HR?

Answer 7

Slow baseline HR will see increased HR with infusion.

High baseline HR will see decreased HR with infusion.

Question 8

Which nerve innervates Carotid sinus?

Answer 8

CN-IX

Question 9

What do atrial stretch receptors sense changes in?

Answer 9

Changes in volume.

Question 10

Location of stretch receptors?

Answer 10

Vena Cava/right atrial junction.

Pulmonary vein/left atrial junction.

Question 11

Stretch receptor activation causes three other related results, What are they?

Answer 11

Decreased sympathetic activity to kidneys.
Decrease vasopressin, Increased atrial natriuretic peptide.
(all of these are trying to get rid of blood via increased urine output.)

Question 12

What is the other name of Bezold-Jarisch Reflex?

Answer 12

Ventricular Receptor Reflex.

Question 13

What does this reflex play a role in?

Answer 13

Blood pressure regulation.

Question 14

Describe the Bezold-Jarisch Reflex:

Answer 14

Strong contraction of an underfilled ventricle elicits the reflex.

Question 15

What is best way to limit the Bezold-Jarisch Reflex with spinal anesthesia?

Answer 15

Give preload prior to spinal anesthetic.

Question 16

The Bezold-Jarisch Reflex is probably involved in what?

Answer 16

Bradycardia and hypotension during coronary reperfursion,
Bradycardia and hypotension with myocardial ischemia/infarction, Bradycardia with profound hypovolemia, Syncope in severe aortic stenosis.

Question 17

What are the “big three” symptoms of aortic stenosis?

Answer 17

CHF, Angina, Syncope.

Question 18

2 Take aways from Bezold Jarisch Reflex:

Answer 18

1. Give epi if severely hypotensive/bradycardic

2. Give preload prior to spinal anesthesia.

Question 19

Where are peripheral Chemoreceptors located?

Answer 19

Aortic and Carotid bodies.

Question 20

Hypoxemia/hypercarbia result in excitation of vasomotor center which causes what?

Answer 20

Increase in SVR»>Increase in MAP.

Question 21

Peripheral Chemoreceptor involvement in BP is not stimulated strongly until what arterial pressure is reached?

Answer 21

Until arterial pressure falls below 80mmHg.

Question 22

How is CNS ischemic response mediated?

Answer 22

Result of decrease blood flow to vasomotor center in medulla.

Question 23

What is the result of the CNS ischemic response reflex?

Answer 23

Increase in BP, Contractility, and HR.

Question 24

What is an example of CNS Ischemic Response?

Answer 24

Patient shocked out of ill-perfusing rhythm, they will typically have sever hypertension following even if drugs were not given.

Question 25

What is Cushing Response a result of?

Answer 25

Increased intracranial pressure.

Question 26

What will you typically see with Cushing triad?

Answer 26

Increased ICP, Hypertension, Bradycardia, irregular breathing.

Question 27

Which happens first, increased MAP or decreased HR in Cushing Response?

Answer 27

Increase MAP from CNS Ischemic response, which then causes baroreceptor reflex which causes decrease in HR.

Question 28

Where are Diving reflex receptors located?

Answer 28

Facial thermoreceptors.

Question 29

What two things do the diving reflex have on the body?

Answer 29

Decrease HR and Increased peripheral vasoconstriction.

Question 30

What stimulus causes Atrial stretch reflex?

Answer 30

Increased Blood volume.

Question 31

What is the response to increased blood volume via atrial stretch reflex?

Answer 31

Makes you pee to decrease blood volume.

Question 32

What stimulus causes Bezold-Jarisch Reflex?

Answer 32

Strong contraction of an empty ventricle

Question 33

Where are receptors located for Bezold-Jarisch Reflex?

Answer 33

Ventricles.

Question 34

What stimulus causes the CNS Ischemic response?

Answer 34

Decreased MAP (blood flow to medulla).

Question 35

Where are the baroreceptors located?

Answer 35

Carotid sinus.

Question 36

What stimulates baroreceptors?

Answer 36

Decreased MAP.

Question 37

What is the response elicited from Diving reflex?

Answer 37

Decreased HR and vasoconstriction.

Question 38

What stimulates Cushing Response?

Answer 38

Increased ICP.

Question 39

What Stimulates Diving Reflex?

Answer 39

Cold water to face

Question 40

Where are Diving reflex receptors located?

Answer 40

Facial thermoreceptors.

Question 41

What stimulates the Bainbridge reflex?

Answer 41

Increased blood volume.

Question 42

What is the response elicited from the Bainbridge reflex?

Answer 42

Increased HR.

Question 43

Where are Bainbridge receptors located?

Answer 43

Atrial/venous junction.

Question 44

What stimulates Peripheral chemoreceptors?

Answer 44

Decreased MAP.

Question 45

What response is elicited from peripheral chemoreceptor reflex?

Answer 45

Increased MAP.

Question 46

Where are peripheral receptors located?

Answer 46

Aortic and Carotid bodies.