Fewell - Neurohumoral control of the heart and circulation

Question 1

Organ Blood Flow (Supply)
is Closely Coupled to
__________________

Answer 1

Organ Metabolic Activity (Demand)

Question 2

ORGAN BLOOD FLOW

is determined by _ and _

Answer 2

DRIVING PRESSURE
and
ORGAN VASCULAR
RESISTANCE

Question 3

What the CONTROLLED

VARIABLE for ORGAN BLOOD FLOW?

Answer 3

systemic arterial pressure
because it is the driving pressure that allows each one of the tissues to determine their own blood flow by altering vascular resistance

Question 4

Blood volume of normal adult

Answer 4

5L

Question 5

Distribution of blood volume in the circulatory system

>heart

Answer 5

7%

Question 6

Distribution of blood volume in the circulatory system

>arteries

Answer 6

13%

Question 7

Distribution of blood volume in the circulatory system

>arterioles and capillaries

Answer 7

7%

Question 8

Distribution of blood volume in the circulatory system

>veins

Answer 8

64%

Question 9

Distribution of blood volume in the circulatory system

>pulmonary vessels

Answer 9

9%

Question 10

where is the majority of blood volume mantained?

Answer 10

in the veins

Question 11

large arteries are called __ vessels

Answer 11

distrubing vessels

Question 12

aterioles are called __ vessels

Answer 12

resistance vessels

Question 13

capillaires are called __ vessels

Answer 13

exchange vessels

Question 14

venules/veins are called __ vessels

Answer 14

capacitance vessels

Question 15

organ flow equation is

Answer 15

organ flow = driving pressure / resistance

Question 16

venule vs arterial side reclining vs upright

Answer 16

reclining has even distrubtion within venules and an even distrubtion within aterial side
>HOWEVER when upright the venule side has a higher concentration/buildup near the legs and feet (because veins are highly compliance and high volume)

Question 17

blood flow equation is

Answer 17

blood flow = driving pressure/vascular resistance
>consider that 120/80 is sufficent in humans to supply blood to organs above the heart (below this may not be able to supply blood to neck, brain …etc BUT above may brust blood vessels)
>BUT in giraffes blood pressure must be 300/180 because some organs are higher up from the heart (probably have more collagen in their walls of arteries to make up for high blood pressure)

Question 18

pulmonary circulation requires adequate driving pressure in the same was that __ does

Answer 18

systemic circulation does
>because the pulmonary circulation also has organs above the heart that need to be reached with the 25/8 blood pressure
>BUT don’t want it too high or too low

Question 19

why is pulmonary circulation have a lower BP than the systemic circulation

Answer 19

the systemic circulation has to reach organs higher up than the pulmonary circulation (ex: brain vs lungs)

Question 20

The heart normally accepts blood at _____ during diastole and
propels it forward at ____
during systole

Answer 20

low filling pressure, higher pressures

Question 21

An adequate blood volume is required for ___

and _

Answer 21

venous return and low-pressure filling of the heart

Question 22

can humans handle a decrease in blood volume and if so how?

Answer 22

Yes using homeostasis! But only a modest (10%) decrease

>e.g. via sympathetic vasoconstriction

Question 23

What do we use to regulate blood volume?

Answer 23

-via low pressure receptors

Question 24

where are low pressure receptors found

Answer 24

• cardiopulmonary (pulmonary vessels)
• atrial (walls)
• large systemic veins

Question 25

what are the effectors of low pressure receptors

Answer 25

hormones and kidneys

Question 26

what do low pressure receptors releases when pressure is low?

Answer 26

-ADH

Question 27

what do low pressure receptors releases when pressure is high?

Answer 27

-ANP

Question 28

Decreased atrial receptor firing causes

Answer 28

hypothalamus -> posterior pitutiary -> vasopressin ->
-v1 -> constriction (increased systemic vascular resistance)
-v2 -> kidney fluid reabsorption (increased blood volume)
_________________________-
leads to increased arterial pressure

Question 29

Arterial receptors function

Answer 29

fine tune/set driving pressure needed to prefuse driving pressure to get nurtients/02 to organs via tissues

Question 30

aterial baroreceptors function

Answer 30

sense pressure (driving pressure) and inform CV center