MM <3 regulators

Question 1

Only the ___ plateaus during exercise (cardiac output)

Answer 1

SV

Question 2

The heart and vasculature are regulated, in part, by:

Answer 2

neural (autonomic)

humoral (circulating or hormonal) factors.

Question 3

Neural mechanisms involve ______________ branches of the autonomic nervous system.

Answer 3

sympathetic adrenergic & parasympathetic cholinergic

Question 4

In general, the sympathetic system stimulates the heart and constricts blood vessels resulting in a rise in arterial pressure.

The parasympathetic system depresses cardiac function and ___________

Answer 4

dilates selected vascular bed

Question 5

There are several very important humoral mechanisms including __________________ (6) . Each of these humoral systems directly or indirectly alter cardiac function, vascular function, and arterial pressure.

Answer 5

circulating catecholamines
the renin-angiotensin system
 vasopressin (antidiuretic hormone)
atrial natriuretic peptide,
 endothelin

Question 6

The medulla, located in the brainstem above the spinal cord, is a major site in the brain for regulating____________________, and is particularly important for short-term feedback regulation of arterial pressure.

Answer 6

outflow to the heart and blood vessels

Question 7

The _______________ (NTS) of the medulla receives sensory input from different systemic and central receptors (e.g., baroreceptors and chemoreceptors).

Answer 7

nucleus tractus solitarius

Question 8

In general, the sympathetic system stimulates the heart and constricts blood vessels resulting in a rise in _________.

The parasympathetic system depresses cardiac function and dilates selected vascular bed

Answer 8

arterial pressure

Question 9

The nucleus tractus solitarius (NTS) of the medulla receives sensory input from different systemic and central receptors (e.g., ____________).

Answer 9

baroreceptors

Question 10

The heart is innervated by vagal and sympathetic fibers. The right vagus nerve primarily innervates the _______ node, whereas the left vagus innervates the AV node

Answer 10

SA node

Question 11

Sympathetic effects on heart function are mediated by beta-adrenoceptors

parasympathetic effects on heart function are mediated by _____________

Answer 11

muscarinic receptors

Question 12

The release of acetylcholine (ACh) from parasympathetic nerves binds to muscarinic ACh receptors, has a direct ________ action (coupled to nitric oxide formation and guanylyl cyclase activation).

Answer 12

vasodilatory

Question 13

The heart is innervated by vagal and sympathetic fibers. The right vagus nerve primarily innervates the SA node, whereas the left vagus innervates the _________ node

Answer 13

AV Node

Question 14

Sympathetic effects on heart function are mediated by ______________

parasympathetic effects on heart function are mediated by muscarinic receptors

Answer 14

beta-adrenoceptors

Question 15

Circulating catecholamines are?

Answer 15

epinephrine and norepinephrine

important humoral mechanisms

Question 16

Epinephrine is released by the __________ upon activation of preganglionic sympathe`tic nerves innervating this tissue.

Answer 16

adrenal medulla

This activation occurs during times of stress

Question 17

Norepinephrine is also released by the adrenal medulla (about 20% of its total catecholamine release is norepinephrine).

The primary source of circulating norepinephrine is spillover from ____________ innervating blood vessels.

Answer 17

sympathetic nerves

Question 18

Circulating Epinephrine Causes:

Answer 18

Increased heart rate and inotropy (β1-adrenoceptor mediated)

Vasoconstriction in most systemic arteries and veins (postjunctional α 1 and α 2 adrenoceptors)

Question 19

Circulating Norepinephrine Causes`

Answer 19

Increased heart rate (although only transiently) and increased inotropy (β1-adrenoceptor mediated) are the direct effects norepinephrine on the heart.
Vasoconstriction occurs in most systemic arteries and veins (postjunctional α 1 and α 2 adrenoceptors)

Question 20

Overall CV response to epinephrine is increased _________ and a small change in mean arterial pressure.

Answer 20

Cardiac Output

Question 21

The overall cardiovascular response to Circulating Norepinephrine is increased cardiac output and systemic vascular resistance, which results in an elevation in __________

Answer 21

arterial blood pressure.

Question 22

Because catecholamines act on the heart and blood vessels through alpha and beta adrenoceptors, the cardiovascular actions of catecholamines can be blocked by treatment with ______________

Answer 22

alpha-blockers and beta-blockers

Question 23

The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating blood volume and systemic vascular resistance, which together influence:

Answer 23

cardiac output and arterial pressure

Question 24

Renin, released by the kidneys, stimulates the formation of angiotensin in blood and tissues, which in turn stimulates the release of ____________ from ___________.

Answer 24

aldosterone from the adrenal cortex

Question 25

Renin is a proteolytic enzyme that is released into the circulation primarily by the kidneys. Its release is stimulated by:

Answer 25

1- sympathetic nerve activation (β1-adrenoceptors) 2- renal artery hypotension 3- decreased sodium delivery to the distal tubules of the kidney.

Question 26

Vascular endothelium has an enzyme, angiotensin converting enzyme (ACE), that cleaves off 2 aa to form _______ from AI

Answer 26

angiotensin II (AII)

Question 27

angiotensin II (AII) functions to:

Answer 27

1- Constricts vessels---> increasing systemic vascular resistance and arterial pressure 2- release aldosterone (adrenal cortex), which in turn acts on the kidneys to increase sodium/fluid retention 3- Stimulates the release of vasopressin (antidiuretic hormone, ADH) 4- Facilitates norepinephrine release from sympathetic nerves 5- Stimulates cardiac hypertrophy and vascular hypertrophy

Question 28

The renin-angiotensin-aldosterone pathway regulated by the mechanisms that stimulate renin release, & also modulated by ___________ released by the heart. These act as an important counter-regulatory system.

Answer 28

natriuretic peptides (ANP and BNP)

Question 29

The main physiological actions of natriuretic peptides ((ANP and BNP) ) is to reduce arterial pressure by ______________

Answer 29

decreasing blood volume and systemic vascular resistance.

Question 30

__________ is a peptide hormone formed in the hypothalamus. Its two primary functions are to retain water in the body and to constrict blood vessels

Answer 30

Vasopressin (aka Argipressin)

Question 31

Mechanisms regulating the release of Vasopressin

Answer 31

Hypovolemia Hypotension Hypothalamic Dehydration

Question 32

cardiopulmonary baroreceptors entering the atria decrease their firing rate when there is a fall in atrial pressure. Nerve fibers from these receptors synapse within the medulla, which signals to hypothalamus for A_________ by the pituitary

Answer 32

Vasopressin (aka Argipressin) release

Question 33

Hypotension, which decreases arterial ____________, leads to enhanced sympathetic activity that increases AVP release

Answer 33

baroreceptor firing

Question 34

___________ located in a region of the hypothalamus regulate AVP release.

Answer 34

Angiotensin II receptors an increase in angiotensin II simulates AVP release.

Question 35

``` Natriuretic peptides (ANP and BNP) is cause decrease renin release, thereby decreasing circulating levels of ______. This leads to natriuresis and diuresis. ```

Answer 35

angiotensin II and aldosterone

Question 36

Taken together, the actions of NPs decrease:

Answer 36

``` ↓ blood volume ↓ arterial pressure ↓ central venous pressure ↓ pulmonary capillary wedge pressure ↓ cardiac output. ```

Question 37

Natriuretic peptides serve as a counter-regulatory system for the ______ system.

Answer 37

renin-angiotensin-aldosterone