Exam 1 - Lecture 3

Question 1

Two components that determine cardiac output:

Answer 1

health of heart and health of system

Question 2

increase of resistance to venous return will cause

Answer 2

less venous return and less cardiac output

e.g. Right atrial pressure 0mmHg has 5L/min of venous return at Psf of 7, but if RA pressure is +4 its 2.5L/min

Question 3

If right atrial pressure increases, what needs to increase in order to raise venous return instead of lowering it?

Answer 3

Higher Psf. If it stays the same, then the delta P falls lower than 7 and it would decrease venous return.

Question 4

Why is making the right atrial pressure negative not as effective as raising the right atrial pressure + also increasing Psf?

Answer 4

if its negative it can only go up to 6L/min bc the veins would collapse from the negative pressure.

Question 5

If body needs to enhance CO for a marathon, it chooses to

Answer 5

Change the Psf!!!!

by tightening arteries to improve blood flow to muscles,

mesenteric arteries clamp down to shut down digestion

Increase BP

Increase venous constriction to raise Psf the most to improve blood returning to heart

Question 6

Primary obstacle to blood returning to heart would be

Answer 6

Chest full of air can compress the vena cavae and return in less venous return, such as during positive pressure ventilation. Counter this by tightening up veins with phenylephrine or more air per breath.

Question 7

What medication can tighten up veins to produce more venous return to heart?

Answer 7

Phenylepherine

Question 8

Where does majority effect of phenylephrine work?

Answer 8

Tightens up the veins more than arteries, and only has to tighten up them a little bit

Question 9

A hypoeffective heart will move the cardiac output curve to the

Answer 9

right

Question 10

A hypereffective heart will move the cardiac output curve to the

Answer 10

left

Question 11

IF someone has a heart problem, what happens to their CVP, and why?

Answer 11

increased and its because the heart cant pump it all out

Question 12

If the heart is weakening, the catecholamines step up. but if its a long term issue, its scaled back and replaced by

Answer 12

volume retention and blood expansion at the kidneys. Norepi and epi increase water retention as well.

Question 13

What is the max cardiac output if we maxed venous return but didnt do anything to the heart?

Answer 13

13L/min

Question 14

When the body wants to increase CO, the main thing the body adjusts is

Answer 14

venous return

Question 15

Output of the heart is geared by the

Answer 15

metabolic rate

Question 16

Conditions that increase metabolic rate/cardiac output (from highest increase of CO to lowest increase)

Answer 16

Beriberi, AV shunts, hyperthyroidism, Anemia, pulm disease, pagets disease

Question 17

Conditions that decrease metabolic rate

Answer 17

Removal of arms and legs, hypothyroidism (lowest metabolic demand).

Question 18

When cardiac output is reduced due to less metabolic demand, what happens to peripheral resistance?

Answer 18

increased to allow less blood flow to tissues.

Question 19

When cardiac output is increased due to more metabolic demand, what happens to peripheral resistance?

Answer 19

Decreased to allow more blood flow to tissues.

Question 20

Beriberi

Answer 20

Vit B1 deficiency, makes cells much less efficient and need to use more energy now.

not common in US, usually only third world countries

Question 21

Why does vascular resistance reduce with AV shunts?

Answer 21

its one more route for the blood to take, reducing resistance

Question 22

Cardiac output is tightly linked to

Answer 22

oxygen consumption

Question 23

Dinitrophenol

Answer 23

old weight loss drug that would drive up metabolic rate

need nervous system to cooperate in order to boost cardiac output on this chart (????)

Question 24

How does dinitrophenol help with blood pressure?

Answer 24

keeps blood pressure from crashing.

arteries dilate and veins will constrict to produce more venous return and cardiac output

Question 25

what drugs should we not take

Answer 25

gas station drugs

Question 26

Cardiac index

Answer 26

L/min/M²

Question 27

What is a normal body surface area

Answer 27

1.7M²

Question 28

What is a normal Cardiac index for a healthy 20 year old 70kg patienrt

Answer 28

3L/min/M2

Question 29

what age does our cardiac index max out?

Answer 29

10 years old

Question 30

Whats a normal max cardiac index

Answer 30

4-5L/min/m2

Question 31

cardiac index of a reasonably healthy 70 year old man

Answer 31

2.4L/min/m2

Question 32

Why does our cardiac index lessen as we age?

Answer 32

less energy expenditure

Question 33

which side of the heart has a steeper cardiac curve?

Answer 33

right ventricle.. think right atrial pressure is 0 and left atrial pressure is 2

Question 34

CVP depends on where you measure.. right outside right atrium is ____ and then further from the heart the pressure gets _____

Answer 34

CLOSE to 0mmHg; higher due to DISTANCE

Question 35

Mean circulatory filling pressure is same as

Answer 35

Psf

Question 36

With an AV fistula, the filling pressure will be _____ and the cardiac output will be _______. Why?

Answer 36

normal;high; resistance to venous return is reduced

Question 37

Reducing resistance to half will increase or decrease venous return?

Answer 37

Increase

Question 38

During hemorrhagic shock, how does heart adjust?

Answer 38

increases right atrial pressure

Question 39

normal intrapleural pressure is

Answer 39

-4mmHg

Question 40

When right atrial pressure increases to +4, how does interpleural pressure change?

Answer 40

Becomes much higher, around +2mmHg

Question 41

-4mmHg is equal to how much cmH2O

Answer 41

-5

Question 42

When you take a breath, it sucks air into lungs but also

Answer 42

sucks blood into heart, therefore there is higher cardiac output

Question 43

During exhalation, how does this adjust cardiac output?

Answer 43

decrease because there is more pressure in the intrapleural space

Question 44

If there is increased intrathoracic pressure, there will be _____ cardiac output. Over time, the body will compensate by ____

Answer 44

reduced; increasing venous return by constricting the venous system

Question 45

If there is a hypoeffective heart with reduced intrapleural pressure (more negative) then the hypoeffective heart will have a _____ shift with a _____ plateau

Answer 45

Left cardiac output curve; lower

Question 46

A hypereffective heart with an increased intrapleural pressure will have what output shift and what plateau

Answer 46

Right shift; high plateau

Question 47

How do arterial specific vasodilators cause increased venous return? Does it alter Psf?

Answer 47

Relax the arterioles to relax the "chokepoint" which will increase the pressure downstream into the venules, which will push the blood faster to the right heart. This does NOT change the Psf

Question 48

SVR is mainly governed where

Answer 48

arterioles

Question 49

Specific example of arterial specific vasodilator?

Answer 49

ACE-I

Question 50

Example of venous specific vasodilator is

Answer 50

nitroglycerin

Question 51

Do venous specific vasodilators change Psf?

Answer 51

yes, it will reduce it

Question 52

How does venous specific vasodilators change delta p?

Answer 52

lowers

Question 53

whats the main purpose/effect of nitroglycerin?

Answer 53

reducing preload and the stress on the heart so it needs less oxygen

Question 54

mixed vasodilators have what result on cardiac output?

Answer 54

dilates both vessels but since venous changes outweigh arterial, it slightly lowers venous return and Psf and therefore cardiac output

Question 55

If we reduce volume or increase venous compliance, the cardiac output will

Answer 55

decrease

Question 56

If we increase volume or decrease venous compliance, the cardiac output will

Answer 56

increase

Question 57

Decreased SVR will result in

Answer 57

increased CO

Question 58

Increased SVR will result in

Answer 58

decreased CO

Question 59

If the heart is damaged, then how will body adjust

Answer 59

Venous compliance reduces (veins tighten up), increased volume retention, and increased SVR