CV A&P

Question 1

cardiac output

Answer 1

amt of blood the heart pumps out of the L ventricle each minute

CO = stroke volume x heart rate

Question 2

cardiac output in HF

Answer 2

diminished because the L ventricle is weakened and cannot adequately pump blood out of the chamber

Question 3

stroke volume

Answer 3

difference between end-diastolic volume (volume of blood at end of relaxation) and end-systolic volume (volume of blood remaining in ventricle after each ejection)

Question 4

3 major factors that influence stroke volume

Answer 4

1. preload (volume of blood in heart)
2. afterload (force opposing ejection of blood from ventricle)
3. contractility

Question 5

preload

Answer 5

chamber volume right before contraction

*lower preload leads to lower SV and vice versa

Question 6

pt with hypovolemia will have…
___ ventricular filling
___ preload
___ stroke volume

Answer 6

less
reduced
lower

Question 7

frank-starling law

Answer 7

states that an increase in resting muscle fiber length results in greater muscle tension

the heart has the ability to change its force of contraction (and SV) in response to change in venous return

Question 8

starling’s capillary forces

Answer 8

3 fluid compartments:
intracellular: fluid inside cells
interstitial: fluid surrounding cells
extracellular: fluid inside capillaries

Question 9

hydrostatic pressure

Answer 9

fluid within the blood exerts hydrostatic pressure

a force that attempts to PUSH fluid out of capillaries and INTO interstitial and intracellular space

Question 10

oncotic (osmotic) pressure

Answer 10

particles within the blood (album, sodium, glucose) exert oncotic pressure

a force that attempts to PULL fluid from interstitial and intracellular space INTO capillaries

Question 11

starlings law of capillary forces

Answer 11

oncotic pressure forces and hydrostatic pressure forces OPPOSE each other at every capillary membrane in attempt to balance each other out

(increase in hydrostatic = decrease in oncotic)

Question 12

afterload

Answer 12

resistance that must be overcome in order to eject blood from chamber

increase in after load –> decrease in SV

Question 13

what determines L ventricular after load?

Answer 13

aortic BP

Question 14

a person with high BP will have…
___ afterload
___ stroke volume

Answer 14

high

be at risk for lower SV

Question 15

contractility is primarily determined by

Answer 15

amount of free calcium within myocardial (heart) cell

increased contractility –> increased SV by causing a greater % of volume to be ejected

Question 16

blood flow

Answer 16

1. superior vena cava and coronary sinus
2. R atrium
3. R ventricle
4. pulmonary artery
5. pulmonary vein
6. L atrium
7. L ventricle
8. aorta

*know the valves

Question 17

L ventricular failure: backward effects

Answer 17

creates a buildup of hydrostatic pressure in the L atrium, pulmonary veins, and pulmonary capillaries

causes pulmonary edema

Question 18

L ventricular failure: forward effects

Answer 18

cause decreased perfusion to brain, kidneys and other organs

activates stimulation of RAAS, ADH, SNS

posterior pituitary release ADH — increases water and increases blood volume

Question 19

pulmonary edema

Answer 19

crackles - opening/closing of alveoli through fluid
*fine = mild
*coarse, bubbly = severe
*cough, dyspnea, orthopnea, paroxysmal nocturnal dyspnea
*pink frothy sputum (severe)

BACKWARD EFFECT OF LVF

Question 20

when the kidneys sense decreased perfusion, what happens?

Answer 20

releases renin from the nephron juxtaglomerular apparatus and initiates cycling of RAAS

RAAS: renin –> angiotensinogen –> angiotensin I –> angiotensin II –> peripheral vasoconstriction and stimulation of adrenal gland –> aldosterone –> Na + H2O reabsorption –> increase blood volume and BP