Download Cardiovascular System: The Heart

Chapter 11
Cardiovascular System: The Heart Cont
2 conduction systems regulate heart activity:
1. autonomic nervous system- __________________________________________
___________________________________________________________________
2. intrinsic conduction (________ system)- a property of the heart, does not
depend on ____________ _____________ impulses, specialized tissue causes
_______________ in only one direction (_______ to _______); enforces
contraction rate of approximately 75 beats per minute
(even if all nerve connections are severed, the heart continues to beat rhythmically)
cardiac conduction system (nodal system)- specialized noncontractile cells that initiate
and distribute impulses throughout the heart
sinoatrial node (SA)- the ___________
right _______________
depolarizes spontaneously 70-80 times per minute
_________________________________________________________________
atrioventricular node (AV)at the junction of the _________ and _________
.04 seconds
delayed .1 seconds at the ______________ (allows atria to complete their contraction)
AV bundle (bundle of His) and bundle branches- in ______________________
septum
Purkinje fibers- spread within the ______________________________
More elaborate on ________ side
Total time from SA node to last ventricular muscle cells is .22 seconds in a healthy
human heart
Contraction is initiated by the ________________ node
Sequential stimulation occurs at other ______________________
Heart sounds
2 distinguishable sounds- ____ and ____
lub= _________________________________________________________
_____________________________________________________________
dup= ______________________ valves snapping shut (aortic just before pulmonary)
Cardiac cycle
All events associated with the ______________________________________________
_____________________________________________________________________
(atrial systole and diastole followed by ventricular systole and diastole)
systole- period of __________________
diastole- period of _________________
(arbitrary starting point)
1. period of ventricular filling (mid to late diastole)
low pressure, _______________________________
AV valves _______
AV valves _______, atrial depolarization, followed by atrial contraction (atrial systole)
Atrial diastole (relaxation through the rest of the cycle)
2. ventricular systole
as atria _______, ventricles begin _______
AV valves closed to prevent _____________
As ventricular pressure builds up, ___________________ valves are forced open, blood
into __________________________________ trunk
3. Early diastole
_____________begin to relax
(throughout ventricular systole, atria were in diastole- filling with blood
as pressure increases, AV valves forced open and ventricular filling begins again)
Cardiac output (CO)
Amount of _____________________________________________
CO = _________________________________________________
Stroke volume
________________________________________________________
Stroke volume _____________ as the force of ventricular contraction
____________
Normal Adult Volume of blood _________ ml passes through the human body once each
minute.
A healthy heart pumps out about ______% of the blood present in its ventricles
That is approximately ____ ml (2oz) per heartbeat
.