Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

31 Cards in this Set

  • Front
  • Back
When is the priming pump action of the atria important in maintaing homeostasis?
The atria acts as a "primer pumps" and under condition of stress, the heart may pump 300% to 400% more blood then during rest. The priming pump action of the atria become important in maintaing pumping efficency.
The volume of blood returing to each ventricle.
How much amount of blood is ejected during each cardiac cycle?
about 70ml per SV
Explain Starling's law of the heart?
The myocardial fibers contract more forcefully when stretched.

Cardiac output = SV x heart rate
what is more important factor than afterload in determing cardiac output?
Explain the concept of peripheral (PVR)vascular resistance and its effects on cardiac output?
Peripheral vascular resistance changes based on stroke volume. If vasodialtion occurs reduces the PVR and the afterload thereby producing an increase in cardiact ouput. In contrast if there is vasoconstriction of arteries will increase PVR and decrease in cardiac output.
muscular contractions of the heart
rate of heartbeat
conduction velocity of heart
At what rate effects the preload and decrease in SV
150 beats or greater
What are the elements that diffuse through the ion channel in a cell membrane
potassium (K), somewhat of Calcium chloride (Ca), and a little bit of sodium (Na).
what is permeable at the resting state?
what channel systems are calcium ions and sodium can enter a cell membrane in cardiac muscle?
There are two sepreate channel systems in the cardiac muscle: fast channels, and slow channels.

Fast channels are sensitive to small changes in membrane potential

slow channel are selective to calcium and lesser in sodium
what ion plays importan role in in contributing to the number of charges as well as the cardiac muscle contraction.
what is the reation in sodium -potassium exchange pump normally transport?
kind of drugs that are calcium channel blockers? without altering the conduction(blocks the slow channel)
verpamil (isoptin)
Diltiazem (cardizem)

antidiysrhythmic blocks inward sodium channel.
resting membrane protential
How many phases are athere in the cardiac action potential?
5 phases
Phase 0
rapid depolariation
Phase 1
early rapid depolarization phase
Phase 2
plateau phase
Phase 3
terminal phase of rapid repolariztion
Phase 4
represents the period between action potentials, when membreane hase returned to its RMP.
At what phase fast sodium channels open momentarily, permitting rapid entry of sodium into the cell.
Phase 0
at what phase that fast sodium channels close, the flow of sodium into cell, and potassium continures to be lost from the cell. The continuation lost of postive electical charges from inside of the cell resulting in a resting permeability.
Phase 1
As what phase is the calcium enters the myocardial cells, triggering a large secondary release of calcium from intracellular storage sites. The prolonged depolarization state allowing time for completion of one muscle contraction before another depolariation begins.
Phase 2
at what phase is the inside of the cell is too negative and it involes the closing of the slow calcium channels and increasing the outflow of potassium.
Phase 3
At what phase is when the membrane has returned to is RMP. The sodium pump is activated to transport out the exess sodium and in with the potassium.
Most negative potential level where threshold is reached.
Phase 4
what is the conduction system composed of?
SA node, AV node, bundle of His.
What are the mose common mechanism in porducing ectopic beats, including cases of PVC's
A fib
atrial flutter
paroxysmal supera ventricular tachycardia (psvt)
what can be assessed for pulse deficit and identifies the location of the mitral valve when assesing heart sounds.
Point of maximum impulse (PMI)