Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Lecture 22

Cardiac Pumping

Cardiac Cycle Sequence of contraction and relaxation. 4 valves, 2 A-V,Aorti/Pulmonar, keep blood flow one way.
Diastole Relaxed heart, time for filling. End diastolic volume ~ 130 mL
Atrial Systole Contracts first completes filling of ventricles
Ventricular Systole Follows atrial contraction. Contraction spreads upward, pressure must be greater than aorta to open aortic valve.
Aortic Pressure Load left ventricle works against high BP puts greater load on heart.
Ejected Blood Volume ~70-90 mL of blood ejected per beat. ~ 65 mL of end diastolic volume. Lower HR means higher ejected volume.
Heart Rate Dependence The max heart rate is (220-age), rates above 180 dec. filling time. Must be motivated to exceed 180. This can dec. cardiac output. Potentially life threatening.
Arterial Pulse Arterial walls expand to hold blood. Rebounds during diastole - creates pulse. Little drop in BP throughout arteries.
Heart Sounds Closing of valves-turbulent blood flow creates sound. Low pressure AV (mitral and tricuspid) first, then high pressure aortic and pulmonary valves, diff. sound intensifies.
Murmurs non- laminar (non smooth)flow-sound when valves should be closed.
Valve Stenosis Stiff valve-small opening. Turbulent flow as blood squirts through.
Valve Insufficiency Valve leaves dont properly mesh. Children w/ improper valve closure, sometimes outgrow this murmur as growth alters valve alignment.
Cardiac Output Amount of blood pumped per min.
Stroke Volume x Heart Rate =CO ~ 7 oml @ 70 beats per min=~5L/min. Body has about 5 L of blood. Circulation time = 1 min.
Starling's Law Stroke volume control raises venous return stretches cardiac muscle rasies force raises CO. More actin myosin interaction, less thick z line contact less thin - thin overlap, more Ca2+ release. Stronger contraction, more SV, more CO
Neural Influences Both SV and HR changed
Parasympathetic Dominant at rest. Cut vagus nerve to heart, HR inc. from 70-100 immed. Exercise raises parasymp output lowers resting. HR: may go to 30-40.
Sympathetic Inc. Ca2+ channel opening. Faster depolarization causes inc. HR. More Ca2+ causes more force, causes inc. SV
Created by: danamarie9323



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards