Term
| what is the cardiac cycle? |
|
Definition
| when the blood moves from areas of high pressure to low pressure(systole, diastole) |
|
|
Term
|
Definition
| contraction period(pressure rises) |
|
|
Term
|
Definition
| relaxation period(pressure falls) |
|
|
Term
| what are the 3 cycles of cardia cycle? |
|
Definition
1. atrial systole-atria contract & ventricles complete filling
2. atrial diastole/ventricular systole: atria relax & ventricles start to contract pressure in ventricles closes AV valve first, then forces open semilunar valves
3. atrial diastole/ventricular diastole: atria & ventricles relaxed atria have been filling, when ventricular pressure drops, AV valves open & ventricles fill |
|
|
Term
| what sound does the heart make, and from what? |
|
Definition
lubb, dupp
-first(lubb)-beginning of ventricular systole when AV valves close
-second(dupp)-beginning of ventricular diastole when semilunar valves close |
|
|
Term
| what's the cardiac output(CO)? |
|
Definition
-amount of blood pumped by each ventricle in one minute
-influenced by beats per minute & how much blood is ejected w/ each beat (ie stroke volume) |
|
|
Term
|
Definition
| CO=heart rate(HR) X stroke volume(SV) |
|
|
Term
| how can the CO be changed? |
|
Definition
altered by changes in either variable
heart rate regulated by autonomic nervous system
stroke volume could inc. by:
more blood returning to heart(blood shunted from GI to muscles)
more blood is pumped out(contraction strength inc. due to sympathetic activation) |
|
|
Term
| the sympathetic nervous system on the CO does what? |
|
Definition
| it increases both the heart rate & stroke volume |
|
|
