BP sections i & II

Question 1

MABP can be altered by a change in either _______ or _________.

Answer 1

TPR or CO

Question 2

MAPB is responsible for driving blood forward into _______ throughout the cardiac cycle.

Answer 2

tissues

Question 3

CVP, although almost 0, is responsible for driving blood forward during diastole and is a measures of pressure where blood enters the ________.

Answer 3

R atrium

Question 4

MABP can be calculated by what equation?

Answer 4

MBP = Dys + 1/3(sys - dys)

Question 5

MABP is regulated by what a reflex & a hormone system what are they?

Answer 5

baroreceptor reflex

RAAS system

Question 6

Baroreceptors are located in the aortic arch & the carotid sinus. They relay information about BP in the circulation to the circulatory center located in the _______.;

Answer 6

medulla oblongota

Question 7

with low BP baroreceptors in the carotid sinus can trigger a reflex that is designed to do what?

Answer 7

insure adequate profusion to the brain by way of message to the medulla oblongata

Question 8

the baroreceptor reflex is the most important mechanism for ________ regulation of BP.

Answer 8

short-term (with-in seconds)

Question 9

A change anywhere in MABP triggers an autonomically mediated baroreceptor reflex that influences the heart and blood vessels to adjust ______ & _______ to maintain BP WNL.

Answer 9

CO & TPR

thus,
CO x TPR = MABP (Pa)

Question 10

a reflex arc includes 5 players who are they?

Answer 10

1. receptor
2. Afferent pathway
3. an integrating center
4. efferent pathway
5. effector organ

Question 11

Baroreceptors continuously generate _______ ________ in response to the ongoing pressure with n the arteries.

Answer 11

action potentials

- increase stretch = increased AP

Question 12

what is the difference in the response from the nucleus tractus solitarius when stimulated by CN IX vs CN X?
what is the over all result to their activation and when would the body want to do this?

Answer 12

CN IX will stimulate a cardiac decelerator = decrease in SA node conduction
CN X will inhibit the sympathetic system = slowing the cardiac accelerator, decreasing vascular tone, decreasing contractility and further slowing SA node conduction
-result = decrease in HR, SV, (CO), TPR, Venous return = decrease in BP
- done in response to high BP

Question 13

in response to acute hemorrhage the baroreceptors in the carotid sinus will?

Answer 13

decrease parasympathetic activity and increase sympathetic

- profuse the brain at all costs!!!!

Question 14

when an animal goes from lying down to standing what happens to the BP and how is it corrected?

Answer 14

-pooling in the venous system from gravity.(decrease in venous return, EDV, SV, thus CO = decrease in BP
this is corrected by the baroreceptor reflex.

Question 15

what is baroreceptor accommodation?

Answer 15

baroreceptor becomes desensitized.
- chronic abnormal BP is registered as normal either from a slow constant rise or a stabilized abnormally high BP
thus, a complication of chronic high BP
- Tx incorporate Beta 1 blocker to regulate HR & contractility.(readjust the norm of the receptors)

Question 16

when is the RAAS system activated? what are its steps?

Answer 16

activated in the response to low BP or Hypovolemia
- decrease in renal profusion –> kidney releases renin –> renin will convert angiotensinogen to angiotensin I. angiotensin I is converted to Angiotensin II by angiotensin converting enzyme by the endothelium of the pulmonary capillary. angiotensisn II will cause vasoconstriction increasing TPR and cause the adrenal cortex to release aldosterone. Aldosterone will tell the kidney to reabsorb more Na+ and H2O will follow it. = increase in BP via increase in venous return, CO and Blood volume.

Question 17

Angiotensin II will increase the release of _______ and slow the reabsorption rate of ______ further activating the sympathetic system.

Answer 17

epinephrine

norepinepherine

Question 18

what is ANP?
where is it produced?
how is it regulated?

Answer 18

atrial natriuretic peptide produced by atrial cardiomyocytes and is regulated by the stretching of the atrium in response to blood volume and pressure.

Question 19

what 3 effects of ANP’s oppose angiotensin II?

Answer 19

it does the opposite action

• promotes Na+ loss thus water loss
• inhibits the secretion of water = conserving hormones such as ADH & Aldosterone
• suppresses thirst

Question 20

secretion of ADH is increased by 2 types of stimuli. what are they?

Answer 20

1. increase in serum osmolality.
   
   • dehydration or hemorrhage
2. decrease in atrial blood pressure.
   
   • decreased stim of baroreceptors

Question 21

how does ADH raise BP?

Answer 21

• tells the kidney to retain more water (ADH has a low affinity for V2 receptor)
• causes arteriole constriction= increase TPR (high affinity for V1 receptor -used in large hemorrhage situations)