The primary function of the cardiovascular system is the transport of ____ to and from all parts of the body.
Nutrients, water, gases, wastes, and chemical signals
Blood vessels that carry blood away from the heart
arteries
Blood vessels that carry blood to the heart
veins
Blood flows down a ___ from the highest pressure in the aorta and arteries, to the lowest pressure in the vena cava and pulmonary veins.
pressure gradient
The pressure created when the ventricles contract is called the ___ for blood flow
driving pressure
In a system in which fluid is flowing, pressure ___ over a distance.
decreases
___ of fluid flowing through a tube increases as the length of the tube and the viscosity of the fluid increases, and as the radius of the tube decreases. (of these factors, radius has the greatest effect)
Resistance
If resistance increases, flow rate ___.
decreases
___ is the volume of blood that passes one point in the system.
Flow rate
___ is the distance a volume of blood travels in a given period of time. At a constant flow rate, the __ of flow through a small tube is faster than the __ through a larger tube
Velocity
The heart is composed mostly of cardiac muscle or ____.
Myocardium
The signal for contraction originates in ____ in the heart. These cells are noncontractile myocardium
Autorythmic cells
Myocardial cells are linked to one another by ____ that contain gab junctions. These junctions allow depolarization to spread rapidly from cell to cell.
intercalated disks
In contractile cell excitation-contraction coupling, an action potential opens Ca2+ channels. Ca2+ entry into the cell triggers the release of additional Ca2+ from the sarcoplasmic reticulum through _____.
Calcium-induced calcium release
The force of cardiac muscle contraction can be graded according to how much___enters the cell.
calcium (Ca2+)
The action potentials of myocardial contractile cells have a rapid depolarization phase due to K+ efflux. The action potential also has a plateau phase created by _____.
Ca2+ influx
Autorhythmic myocardial cells have an unstable membrane potential called _____.
Pacemaker potential
Pacemaker potential is due to _____ that allow net influx of positive charge.
I-f Channels
The steep depolarization phase of the autorhythmic cell action potential is cased by Ca2+ influx. The repolarization phase is due to ____.
K+ efflux
Action potentials originate at the ____ and spread rapidly from cell to cell in the heart.
Sinoatrial (SA) nodes
The electrical signal moves from SA node through the ______ to the atrioventricular node.
internodal pathway
From the AV node electrical signals move to the AV bundle, bundle branches, _____, and myocardial contractile cells.
terminal Purkinje fibers
The ____ sets the pace of the heartbeat. If this node malfunctions, other autorythmic cell sin the AV node or ventricles take control of the heart.
SA node
In an electrocardiograph the ___ represents atrial depolarization.
P wave
In an electrocardiograph the ___ represents ventricular depolarization.
QRS Complex
In an electrocardiograph the ___ represents ventricular repolarization.
T wave
An ECG provides information on heart rate and rhythm, conduction velocity, and ____.
Condition of cardiac tissues
One ___ includes one cycle of contraction and relaxation.
Cardiac cycle
___ is contraction phase, ___ is relaxation phase.
Systole, Diastole
___ prevent backflow of blood into the atria.
AV Valves
During ____, the ventricular blood volume does not change, but pressure rises. When ventricular pressure exceeds arterial pressure, the semilunar valves open, and blood is ejected into the arteries.
Isovolumic ventricular contraction
First heart sound
AV valves close
Second heart sound
Semilunar Valves close
The amount of blood pumped by one Ventricle during one contraction is known as ___ volume
stroke
___ is the volume of blood pumped per ventricle per unit time. It is equal to heart rate times stroke volume.
Cardiac Output