neurohumoral control

Question 1

Which sympathetic nerve receptor predominantly causes vasoconstriction?

Answer 1

alpha

Question 2

Which sympathetic nerve receptor predominantly causes increased contractility?

Answer 2

beta 1

Question 3

Which sympathetic nerve receptor predominantly causes bronchodilation?

Answer 3

beta 2

Question 4

Chronotrophy

Answer 4

HR

Question 5

inotropy

Answer 5

contractility

Question 6

dromotropy

Answer 6

conduction velocity

Question 7

lusitropy

Answer 7

relaxation

Question 8

What is the “second messenger” that is involved with sympathetic stimulation of a cardiac muscle cell?

Answer 8

cyclic AMP

Question 9

Which catecholamine does the adrenal gland predominantly release with sympathetic stimulation?

Answer 9

Mostly epinephrine (80%), lesser amount norepinephrine (20%)

Question 10

What is the Baroreceptor Reflex

Answer 10

Sensor of change in BP, increases or decreases HR due to change. Located in carotid sinus and aortic arch

Question 11

Where are the receptors for the baroreceptor reflex located?

Answer 11

Located in Carotid SINUS and Aortic Arch

Question 12

How does the Baroreceptor Reflex help with blood pressure regulation?

Answer 12

Helps ↓ daily variation in blood pressure
Helps with postural changes in BP
Responds rapidly to changing pressure

Question 13

During what surgery does Baroreceptor Reflex activation frequently cause hemodynamic changes?

Answer 13

Carotid endarectomy

Question 14

What is the Bainbridge Reflex?

Answer 14

Infusion of ↑ VOLUME causes ↑ HR due to activation of atrial stretch receptors

Question 15

Where are the receptors for bainbridge reflex located?

Answer 15

Vena cava – right atrial junction

Pulmonary vein – left atrial junction

Question 16

In addition to receptor activation what also contributes to the heart rate changes seen with the Bainbridge Reflex?

Answer 16

Stretch of heart and stretch of SA node

Question 17

The Baroreceptor Reflex responds to changes in arterial blood pressure or to changes in blood volume?

Answer 17

pressure

Question 18

The Bainbridge Reflex responds to changes in arterial blood pressure or to changes in blood volume?

Answer 18

volume

Question 19

What are some of the effects of Atrial Stretch Receptor activation?

Answer 19

↓ Volume by ↑ Urine output and ↓ BP

↑HR (Bainbridge)

Question 20

What is the Bezold-Jarisch Reflex?

Answer 20

strong contraction of an undefiled ventricle => ↓HR, BP, and SVR

Question 21

What is the CNS ischemic response?

Answer 21

Atrial pressure elevation in response to cerebral ischemia

Question 22

What is the Cushing Response?

Answer 22

Increased ICP causes increased BP until blood flows once again in the vessels of the brain

Question 23

What is Cushing’s Triad?

Answer 23

Irregular respirations (caused by impaired brainstem function), bradycardia, and widening pulse pressure (caused by systolic hypertension).

Question 24

Under what circumstances can Peripheral Chemoreceptors cause hemodynamic changes

Answer 24

When SBP< 80mmHg => ↓PaO2, ↑PaCO2, ↓pH => excites vasomotor center in medulla => ↑ SVR and MAP

Question 25

What is the Diving Reflex?

Answer 25

the body’s physiological response to submersion in cold water and includes selectively shutting down parts of the body in order to conserve energy for survival.

Question 26

Vasopressin is released from which part of the brain? What are the effects of vasopressin on blood pressure? What are the effects of vasopressin on the kidney?

Answer 26

1. Vasopressin is released from the hypothalamus. Increases BP. Greatly increases water reabsorption from the renal tubules back into the blood and therefore helps to control body fluid volume. (antidiuretic hormone)

Question 27

What is the stimulus for release of Atrial Natriuretic Peptide?

Answer 27

ANP is released by the atrial walls of the heart when they are stretched

Question 28

What are the effects of ANP on blood pressure?

Answer 28

The ANP has a direct effect on the kidneys to increase greatly their excretion of salt and water. Therefore, ANP plays a natural role to help prevent extreme congestive systems during cardiac failure. Causes Decreased BP

Question 29

What converts angiotensinogen to angiotensin I?

Answer 29

renin

Question 30

What converts angiotensin I to angiotensin II?

Answer 30

1. Angiotension-converting enzyme (ACE). Located in the lungs

Question 31

What are the INDIRECT effects of hypoxia on the circulatory system?

Answer 31

SNS activation. Increased HR, Increased CO, increased contractility.

Question 32

What are the DIRECT effects of hypoxia

Answer 32

Depressed myocardial contractility

Question 33

What are the INDIRECT effects of hypercarbia on the circulatory system

Answer 33

SNS activation. Increased HR, Increased CO, increased contractility. \

Question 34

what are the direct effects of hypercarbia

Answer 34

depressed myocardial contractility