Normal A&P Review of Cardiac

Question 1

cardiac output

Answer 1

CO= SV x HR
amount of blood ejected from LT ventricle each minute
diminished in HF, r/t weakened LT ventricle

Question 2

Stroke Volume

Answer 2

the difference between end diastolic volume and end systolic volume
3 major factors influence stroke volume, preload, afterload, and contractility

Question 3

preload

Answer 3

volume of blood in the heart just prior to contraction

preload is related to stroke volume

Question 4

afterload

Answer 4

resistance that must be overcame in order to eject blood from chamber
LT ventricle afterload primarily determined by aortic BP
increased afterload can decrease SV unless heart compensates

Question 5

contractility

Answer 5

contractile capabilities of the heart
primarily determined by amount of free calcium within myocardial cells
increased contractility increases SV

Question 6

frank-starling law

Answer 6

an increase in resting muscle fiber length results in greater muscle tension
“length-tension” relationship
heart has the ability to change its force of contraction and SV in response to venous return

Question 7

what are the three capillary forces in starlings law?

Answer 7

intracellular, interstitial, extracellular

Question 8

hydrostatic pressure

Answer 8

fluid within blood
a force that attempts to push fluid out of capillary and into interstitial and intracellular spaces
*water-pushing-pressure

Question 9

oncotic (osmotic) pressure

Answer 9

a force that attempts to pull fluid from interstitial and intracellular spaces into capillaries
*water-pulling-pressure

Question 10

starlings law of capillary forces

Answer 10

oncotic pressure forces and hydrostatic pressure oppose each other and try to balance each other

Question 11

blood flow through heart

Answer 11

vena cava gives blood to
RT atrium
RT ventricle
Pulmonary artery and lungs
oxygenated blood from pulmonary veins to LT atrium
LT Ventricle
Aorta

Question 12

LT Ventricle Failure backwards vs fwd effects

Answer 12

backward effect of failing lt ventricle creates hydrostatic pressure in lt atrium, pulmonary veins, and pulmonary capillaries
fwd failure effects cause decreased perfusion of the brain, kidneys, and other organs

Question 13

backwards LVF

Answer 13

buildup of hydrostatic pressure backwards into LT atrium and pulmonary vasculature causing pulmonary edema

Question 14

how does backwards LVF present?

Answer 14

heard as crackles
presents as cough, dyspnea, orthopnea, paroxysmal nocturia dyspnea
pink frothy sputum and coarse bubble crackles with severe PE

Question 15

forwards LVF

Answer 15

cause inadequate ejection of blood into aorta and diminished perfusion throughout whole circulatory system
stimulates RAAS, ADH, and SNS
kidney sense low perfusion and start RAAS system
ultimately increases blood volume and pressure