Cardiac output

Question 1

Define cardiac output

Answer 1

Volume of the blood that is ejected.
Left output = R output
Venous return = cardiac output

Question 2

Direct Fick method

Answer 2

uses O2 content of arterial blood, mixed venous blood & O2 consumption

Question 3

Dye dilution method

Answer 3

dye, thermal dilution, radioisotope dilution measured on right side

Question 4

Frank Starling law

Answer 4

Stretch of force of contraction are linearly proportional to upper limit
As ventricle fills more stretch is produced prior to stimulation
Increased stretch = more forceful contraction

Question 5

Explain FS CO venous

Answer 5

Increase in venous return will fill the ventricle

Increase amount will pumped out

Question 6

Explain right to left CO

Answer 6

Given volume of blood delivered to the right heart will be pumped to lungs to left side and to system

Question 7

Compensation under resting conditions

Answer 7

Increased HR decreased stroke volume. If the stroke volume stayed the same cardiac output would increase

Question 8

Sympathetic or PS

Answer 8

Diff NT can either increase or decrease the force of contraction independent of LVEDV.

Question 9

Negative inotropic

Answer 9

Decrease force of contraction CHF

Acetylcholine

Question 10

Positive inotropic

Answer 10

Increases force of contraction
Epinephrine
Nor epinephrine

Question 11

LVEDV decreases

Answer 11

the ventricle has less time to fill due to the increased HR

Question 12

LVESV decreases

Answer 12

During exercise the heart contracts more forcefully so it empties more

Question 13

CO

Answer 13

SV X HR

Question 14

Role of adenosine in matching coronary profusion to cardiac metabolic needs

Answer 14

Formed by breakdown of ATP to AMP enzyme removes phosphate in hypoxic conditions in heart
Causes vasodilation results in increased blood flow

Question 15

Describe effects of epi

Answer 15

HR increases
Glycogenolysis
MB permeability to Ca
Contractility increase
Increased CO

Question 16

Norepi on cycle

Answer 16

Increases rate at which Ca is pumped out

Shorter relaxation time more efficient faster filling of the ventricles

Question 17

Ischemic heart

Answer 17

Are stiffer cannot actively pump Ca at norm rate to relax properly

Question 18

PsF

Answer 18

Avg pressure in systemic cirulation

Question 19

Altering factors of PsF

Answer 19

Change in blood volume
Change in sympathetic tone
Massaging of veins by skeletal muscle

Question 20

Relationship btw venous return, PsF & right atrial pressure

Answer 20

VR is proportional to PsF minus RaP
RaP is the pressure that must be overcome to return blood back to heart
RaP increasing CHF, CO output decreases

Question 21

Explain norm VR curve w/ increased sympathetic tone

Answer 21

5.0 L/min average aP 0

During exercise tone increases and contractility increases but aP does not increase to much