Chapter 13
how many cardiac occur from the beginning of one heart beat to the beginning of the next
1
A segment of an ECG is
A straight line between two waves
Which equation correctly depicts the relationship between blood pressure (BP), peripheral resistance (PR), and cardiac output (CO)?
BP = CO x PR
Endocardium Pericardium Myocardium
Place the three layers of the heart in order from inside to outside,
What is the function of chordae tendineae?
Prevent the cusps of the AV valves from opening back into the atrium.
The first heart sound, "lubb" is heard when AV valves close, and this is related to the ______ on an ECG
QRS
Place the wave with the highest amplitude at the top.
R, T, P
In the cardiovascular system, what vessels are the site of nutrient, gas, and waste exchange?
capillaries
The heart contracts because of an electrical impulse. Where in the heart does this impulse start?
SA node
The stimulation of the heartbeat begins in the _____, which is why this structure is called the pacemaker of the heart
SA node
What wave in an ECG tracing depicts ventricular repolarization?
T wave
At which point on an ECG is the second heart sound, "dupp", heard
The end of the T wave
What is systolic pressure?
The maximum pressure achieved during ventricular contraction.
what is the function of the four heart valves
They allow the blood to flow in only one direction through the heart.
The AV valves are closing during ventricular
contraction (systole)
How are the sounds of a heartbeat in a healthy heart created
by heart valves closing
As a result of a sudden increase in the blood pressure, signals from baroreceptors lead to a(n) ___ in sympathetic outflow from the vasomotor center, which results in a(n) ___ in peripheral resistance and return of blood pressure to normal.
decrease, decrease
Arterial blood pressure would decrease due to a ______ peripheral resistance from ____ of arterioles.
decrease; dilation
When the heart contracts, this is due to an electrical change called _________
depolarization
What does an ECG measure
electrical impulses
The electrical activity that occurs in the heart when it contracts and relaxes can be recorded, and the recording is called an
electrocardiogram
The second heart sound, "dupp" is heard when the semilunar valves close, and this is related to the _______ on an ECG
end of the
What is the innermost layer of an artery wall called?
endothelium
blood leaves the ventricles during which period
from the end of the first heart sound to the beginning of the second heart sound
if you record an ECG on a test subject that has just exercise, it will show an increase in
heart rate
aortic valve
heart valve between the left ventricle and the aorta
the SA node is located where
in the right atrium
mitral (or bicupsid, atrioventricular valve controls the flow between the
left atrium and ventriicle
A turbulent noise, created by the back flow of blood as a heart valve closes, is called a heart
murmur
An interval of an ECG is
one or more waves and a straight line
A cardiac cycle is
one set of atrial contractions followed by one set of ventricular contractions
A cardiac Cycle
one set of atrial contractions. followed by one set of ventricular contractions
The semilunar valves are closing during ventricular
relaxation (diastole)
Which ventricle pumps blood through the pulmonary artery to the lung
right ventricle
What blood vessel is a tributary of the hepatic portal vein?
splenic v.
The P-Q (or P-R) interval is the time it takes for
the electrical impulse to spread through the atria
Which factors are important when trying to obtain an accurate ECG recording
the electrodes should adhere properly to the skin; the electrodes should be in their correct positions
femoral artery
the major artery supplying the leg
The ventricles relax during
the second heart sound
What is happening in the heart during the second heart sound "dupp"
the semilunar valves are closing
A cardiac cycle covers the events that occur from the beginning of one heart beat to the beginning of the next
true
depolarization and repolarization are responsible for making the heart contract and relax
true
true or false: The ventricles contract during the first hand sound
true
mitral valve
valve between the left atrium and the left ventricle; bicuspid valve
tricuspid valve
valve between the right atrium and the right ventricle
pulmonary valve
valve positioned between the right ventricle and the pulmonary artery
The first heart sound, "lubb", is associated with the closing of which valves
AV valves
normal
An average adult with a heart rate of 70 beats. per minute has a ______ heart rate
the electrical impulse is delayed in the AV node before propagating to the bundle of his. During this delay the ________ contract
Atria
In an ECG, the _____ wave is associated with atrail depolarization.
P
Electrical
________ impulses stimulate cardiac muscle to contract
The parasympathetic fibers of the vagus nerve secrete ____, which ____ the heart rate.
acetycholine; decreases
the heart contracts because of
an electrical impulse
The _______ line is a straight line used as a point of departure for the electrical activity recorded in an ECG
base
