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CBIOL Cardiovascular Physiology
Terms in this set (94)
One complete heart cycle; lasts 0.8 seconds, aka heart beat; marked by the changes in blood pressure and volume in the heart
75 beats per minute
average human heart rate
lasts 0.1 seconds, fills relaxed ventricles, first phase of the cardiac cycle
lasts 0.3 seconds, pumps blood out of the heart, second phase of cardiac cycle
lasts 0.4 seconds, blood enters ventricles during resting period, third phase of cardiac cycle
in the heart itself
Where do heart beats originate?
Cardiac Conduction System
1. initiates signal for contraction 2. Provides a pathway for conducting the signal to all cardiac muscle fibers
Allows for the initiation of an electrical impulse across the cell membrane
outside of the cell has more positive ions than does the inside
A change in the charge across the cell membrane
Sodium enters slowly then calcium
Potassium leaves the cell
Sinoatrial Node (SA Node)
pacemaker, located in the wall of the right atrium just velow the superior vena cava, initiates the electrical impulse in the heart, casues atria to contract
Located in the lower atrial septum, receives the electrical impulse from the atria muscle fibers, causes a 0.1 second delay, allows atria to contract prior to ventricular firing
Bundle of HIS, located in a septum between the atria and ventricles, the electrical connection between the atra and ventricles, reveices signals from the AV node, sends signals to the bundle branches
located in the interventricular septum, sends signals to the Purkinje fibers, right and left bundle branches
located in the apex of the myocardium and the lateral walls of the right and left ventricle, send signals to the ventricular cardiac muscle starting from the apex and spreading upward, ventricles contract
Heart sounds; used to diagnose and evaluate valve function
amplifies the sounds of the heart to an audible level
S1; caused by closure of the AV valves as ventricles begin to contract
S2; occurs as the SL valves close at the beginnnig of ventricular diastole
Sloshing in; too much fluid volume results in the blood oscillating between the walls of the ventricles when blood rushes in from the atria
Stiff Wall; ventricular hypertrophy; makes sound during atrial contraction due to higher pressure
Measure of the force the blood exerts on the walls of the systemic arteries
LV contracts and pumps blood into the Aorta thereby increasing arterial pressure; 1st Korotkoff sound; pressure that exceeds the cuff
LV relaxes, less blood flows into aorta, arterial pressure decreases; absence of korotkoff sounds
Average BP of a male
Average BP of a female
cardiac output, blood volume, and peripheral resistance
Arterial blood pressure is affected by
the volume of blood discharged from the left ventricle into the aorta each minute at rest
Amount of blood pushed from the left ventricle in a single contraction
The body's total volume of blood
the friction caused by blood flow against the vessles walls, dependent on hormone levels, activity levels, weight, age, and kidney function
Used the measure arterial blood pressure; cuff that is inflated to block blood flow in the brachial artery
Chronic resting BP above 140/90; can weaken small arteries and cause aneurysms
Chrpnic low resting BP; causes: blood loss, dehydration, anemia
how heart rate is determined
Blood pressure increases and stretched the walls of the arteries
Blood pressure decreases and arterial walls rebound
A recording of the impulses (aka EKG)
first event, represents atrial depolarization, arises from SA node just before atrial contraction
Represents the time for an impulse to travel from the AV node to the ventricles
Occurs between the start of the P wave and start of the QRS Complex, represents the time required for an impulse to travel from the SA Node to the ventricular muscle
Measures the delay between ventricular depolarization and repolarization
Represents ventricular repolarization just before the ventricles relax
The cycle of ventricular depolarization and repolarization
Heart rate above 100 beats/min
Heart rate below 60 beats/min
Prolonged tachycardia, rapid uncoordinated contraction, no blood is pumped
The sinoatrial node has a common name. What is it?
Which two chambers of the heart (atria or ventricles) contract last in a normal cardiac cycle?
What two chambers are stimulated immediately after the SA node depolarizes?
Atrioventricular bundle, bundle branches, Purkinje fibers
After the AV node depolarizes what structures conduct the impulse to the myocardium of the ventricles?
P wave, QRS Complex, T wave
What are the main events recorded by an ECG?
What electrical event in the heart does the QRS complex represent?
Ventricular repolarization is represented by what part of an ECG?
What ECG wave represents the atrial depolarization?
It occurs at the same time as ventricular depolarization which is the larger electrical event
Why is the ECG event indicating atrial repolarization not seen in an ECG?
slows the impulse in the heart and lengthens the QRS complex of the ECG
What does a heart block do to impulse transmission in the heart?
Random contraction in cardiac muscle results in numerous loci of contractions, atria and ventricles could (fine) at different rates which could be antagonistic to each other & reduce efficiency of heart
What effect does fibrillation have on cardiac muscle contraction and on pumping efficiency of heart? Which is more serious-atrial or ventricular fibrillation?
Portion of ECG electrically measured events of bundle branches would be altered, would see an increase of time of QRS interval
If myocardial infarct (heart attack) destroyed a portion of the right or left bundle branches what change would you see in an ECG?
Fatty deposits in the walls of the arteries.
A short period of elevated blood pressure.
Lasts for much longer periods of time and is a
significant health concern.
Blood pressure is measured in the brachial artery,
which is at the level of the heart and has the
approximate pressure of the blood leaving the heart.
The sounds made by the flow of blood in a partially
brachial artery; it is located at the same level as the
heart and has about the same pressure as blood leaving the heart
To measure blood pressure, what artery would you most commonly use and why?
diastolic pressure; resting phase
If you have a blood pressure of 140/80, what does the 80 represent? What phase is the heart in at this point?
What is the clinical threshold for high blood pressure in young adults?
When the first sound is heard during measurement with a blood pressure cuff, what is measured - systolic or diastolic
before the ventricles
During the cardiac cycle, the atria contract:
depolarization of the atria
The P-wave in the human electrocardiogram is associated with:
the QRS complex
In the ventricles, the depolarizing phase of the action potential is associated with:
the ventricles contract
The AV valves close and produce the "lub" sound when:
the ventricles relax
The semilunar valves close and produce the "dup" sound when:
the electrical activity of the heart
The electrocardiogram measures:
the P wave
In the atria, the depolarizing phase of the action potential creates:
The heart rate can be calculated if you know the time interval between:
the time interval between T-wave and the next P-wave
If the action potentials do not change and the timing between the atrial and ventricular action
potentials remains constant, which time interval will change when the heart rate increases?
is greater than the blood pressure in the left ventricle.
In the relaxed heart, the blood pressure in the aorta:
The AV valves close
Which of the following events takes place first after the atria contract?
the semilunar valves close and produce the dup heart sound.
In the human heart, the ventricles relax and:
the elastic recoil of the aorta
The dicrotic notch is produced by:
once during each cardiac cycle
The electrocardiogram (ECG) is composed of a P-wave, a QRS complex, and a T-wave. These three
components are measured:
action potentials in the atria and ventricles
The electrocardiogram (ECG) measures:
to the left of the midline
In most people, the heart is located:
pointing downward, at some angle between horizontal and vertical
The heart lies in the thorax with its long axis
the SA node
The pacemaker for the human heart is found in:
the AV node
The action potential passes from the SA node to the ventricles via:
the P-wave and the QRS complex would increase
If there were a sudden increase in the time taken for the action potential to travel through the AV
node, the time interval between:
specialized muscle fibers
An action potential travels from the AV node to the ventricles by:
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