Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
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
Normal Size Small Size show me how
Cardiac cycle/output
| Question | Answer |
|---|---|
| What is systole | contraction period of the heart |
| What is diastole | relaxation period of the heart |
| What does the cardiac cycle include | all events associated with the blood flow through the heart during one complete heart beat |
| In the cardiac cycle, atrial systole and diastole are followed by what | ventricular systole and diastole |
| What is the first part of the cardiac cycle | ventricular filling |
| In ventricular filling, is the heart in systole or diastole | mid to late diastole |
| What is the pressure like in the heart in the first step | low |
| The blood returning from circulation in ventricular filling is flowing passively through the atria and what | the AV valves |
| What valves are closed during ventricular filling | pulmonary |
| What percentage of blood fills the ventricles during this stage | 80 |
| After most of the ventricles are filled, what starts to drift closed | the AV valves |
| What percentage of blood is delivered to the ventricles after the atria contract | 20 |
| When atrial systole occurs, what happens to the blood in their chambers | it is compressed |
| This causes a rise in what | arterial pressure |
| This rise propels residual blood into what | ventricles |
| At this point, the ventricles are in the last part of what | diastole |
| What is the EDV | the end diastolic volume; the point at which the ventricles have the maxiumum volume of blood they will contain in the cycle |
| What is the second step of the cardiac cycle | Ventricular systole |
| As the atria relax, what do the ventricles do | contract |
| What happens to the walls of the heart when the ventricles contract | they close in on the blood in their chambers |
| What happens to the ventricular pressure | it rises rapidly |
| What does this cause the AV valves to do | close |
| What is isovolumentric contraction | the split second where all of the valves are closed and the blood is completely contained |
| When the pressure continues to rise and finally exceeds pressure in the large arteries, what happens | blood is expelled from the ventricles |
| When the isovolumetric contraction ends, what happens | the SL valves open and expell the blood into the aorta and pulmonary trunk |
| When the SL valves open and expell the blood into the Aorta and pulmonary trunk, this is called | the ventricular ejection phase |
| What is the last part of cardiac cycle | isovolumetric relaxation |
| Isovolumetric relaxation happens when | early diastole of the ventricles |
| What is the ESV | end systolic volume; the blood remaining in their chambers during early diastole of ventricles |
| In the ESV, the blood is no longer | compressed |
| This causes what to happen to the pressure | it rapidly drops |
| This causes the blood in the aorta and pulmonary trunk to do what | flow back toward the heart and close the SL valves |
| This causes what | the dicrotic notch |
| What is the dicrotic notch | the brief rise in aortic pressure |
| What is cardiac output | the amount of blood pumped out by each ventricle in one minute |
| CO= | heart rate x stroke volume |
| The heart rate stands for what | how many beats per minute |
| the stroke volume stands for what | the volume of blood pumped out by a ventricle with each beat |
| Stroke volume is correlated with what | the force of ventricular contraction |
| At rest, CO= | HR(75 beats/min) x SV (70 ml/beat)= 5 25 L/min |
| What is maximal cardiac out put | 4-5 times the resting CO in a nonathletic person |
| In trained athletes, what can cardiac output reach | 35 L/min |
| What is cardiac reserve | the difference between resting CO and maximal CO |
| The sympathetic nervous system is activated by what | emotional and physical stressors |
| This causes the release of what from the sympathetic nerve fibers | norepinephrine |
| This release causes the pacemaker to do what | fire rapidly so the heart responds and beats faster |
| What does ACh do to the pacemaker cells | hyperpolarizes them by opening the K+ channels |
| Because the heart has a vagal tone, what does this mean about the heart rate | if the vagal nerves did not innervate it the heart rate would be much faster |
| What is the Atrial (Bainbridge) reflex | sypathetic reflex initiated by increased venous return and atrial filling |
| In the atrial reflex, how does the stretching of arterial walls increase heart rate | by stimulating the SA node and the atrial stretch receptors which activate sympathetic reflexes |
| What are other influences on heartrate | age, gender, exercise, body temperature |
| What is tachycardia | abnormally fast heart rate |
| If tachycardia is persistant it may lead to | fibrillation |
| What is bradycardia | heart rate slower than 60 bpm |
| This can result in what | grossly adquate blood circulation |
| Bradycardia may be a desirable result of what | endurance training |
| What is congestive heart failure | a progressive condition where CO is so low that blood circulation is inadequate to meet tissue needs |
| Congestive heart failure can be caused by | coronary atherosclerosis, persistant blood pressure, multiple myocardial infarcts, dialated cardiomyopathy |
| What are the 2 fetal heart structures that bypass pulmonary circulation | foramen oval and ductus arteriosis |
| What does the foramen ovale connect | the two atria |
| What does the ductus arteriosis connect | pulmonary trunk and aorta |
| Congenital heart defects leads to the mixing of what | systemic and pulmonary blood |
| Congenital heart defect involves | narrowed valves or vessels that increase the work load on the heart |
| What are four age related changes | sclerosis and the thickening of valve flaps, decline in cardiac reserve, fibrosis of cardiac muscle, and atherosclerosis |
Created by:
100000098798375
Popular Biology sets