If the vagal nerves to the heart were cut, the result would be that ________.
the AV node would become the pacemaker of the heart
the heart would stop, since the vagal nerves trigger the heart to contract
parasympathetic stimulation would increase, causin
the heart rate would increase by about 25 beats per minute
Damage to the ________ is referred to as heart block.
AV Node
Which vessel of the heart receives blood during right ventricular systole?
Pulmonary Trunk
During the period of ventricular filling ________.
the P wave on the ECG has the peak
the atria remain in diastole
pressure in the heart is at its peak
blood flows passively through the atria and the open AV valves into the ventricles
Blood passively flows through the atria and the open AV valves into the ventricles.
The time of day most hazardous for heart attacks is ________.
Morning
If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________.
heart rate would decrease, but blood pressure would rise due to the excess sodium present
tetanic contraction would occur due
threshold is reached more quickly and heart rate would increase
Tissues damaged by myocardial infarction are replaced by connective tissue.
True
Norepinephrine acts on the heart by ________.
Causing the threshold to be reached more quickly
Hemorrhage with a large loss of blood causes ________.
a lowering of blood pressure due to change in cardiac output
Which of the following is not part of the conduction system of the heart?
AV valve
AV node
bundle of His
SA node
AV Valve
Isovolumetric contraction ________.
refers to the short period during ventricular systole when the ventricles are completely closed chamber
Which of these vessels receives blood during ventricular systole?
aorta only
both the aorta and pulmonary trunk
pulmonary arteries only
pulmonary veins only
both the aorta and pulmonary trunk
An ECG provides direct information about valve function.
False - ECG is a composite of all the action potentials generated by nodal and contractile cells at any given time
As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.
true
The P wave of a normal electrocardiogram indicates ________.
atrial depolarization
The myocardium receives its blood supply from the coronary arteries.
TRUE
Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle.
FALSE
Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.
TRUE
Tissues damaged by myocardial infarction are replaced by connective tissue.
TRUE
The left side of the heart pumps the same volume of blood as the right.
TRUE
Chronic release of excess thyroxine can cause a sustained increase in heart rate and a weakened heart.
TRUE
Arterial blood supply to the heart muscle is continuous whether the heart is in systole or diastole.
FALSE When the ventricles contract and push the Semilunar Valves open the coronary artery is closed.
Trabeculae carnae are found?
in the ventricles and never the atria.
The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic valves.
FALSE
Autonomic regulation of heart valve is via two reflex centers found in the pons.
FALSE
The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the AV valve flaps.
FALSE
As pressure in the aorta rises, more ventricular pressure is required to open the aortic valve.
TRUE
What is tachycardia
bursts of atrial contractions with little pause between them.
Which of the events below does not occur when the semilunar valves are open?
-Ventricles are in diastole.
- Ventricles are in systole.
-Blood enters pulmonary arteries and the aorta.
- AV valves are closed.
Ventricles are in Diastole
The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________.
pumps a greater volume of blood
pumps blood against a greater resistance
sends blood through a smaller valve
expands the thoracic cage
Pumps Blood against a greater resistance
Which is correct?
--The tricuspid valve divides the left atrium from the left ventricle.
-- The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
-- Aortic and pulmona
The AV valves are supported by chordae tendineae so that regurgitation of blood into the atria during ventricular contraction does not occur.
The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________.
myocardial infarct
pericarditis
angina pectoris
ischemia
angina pectoris
The source of blood carried to capillaries in the myocardium would be the _______
coronary arteries
Blood within the pulmonary veins returns to the ________.
left atrium
which is correct?
--Connective tissue in the heart wall aids in the conduction of the action potential.
--The heart chambers are lined by the endomysium.
--The myocardium is the layer of the heart that actually contracts.
--The fibrous skeleton forms the
The myocardium is the layer of the heart that actually contracts.
Small muscle masses attached to the chordae tendineae are the ________.
papillary muscles
When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________.
noticing the thickness of the ventricle walls
The left ventricular wall of the heart is thicker than the right wall in order to ________.
pump blood with greater pressure
The heart is actually (one, two, or three) pumps?
two pumps
Which chamber receives blood from the superior and inferior vena cavae?
right atrium
Which heart chamber receives blood from the pulmonary veins?
left atrium
Which heart chamber pumps unoxygenated blood out the pulmonary trunk?
right ventricle
Which chamber pumps oxygenated blood out the aorta to the systemic circuit?
left ventricle
Select the correct statement about the function of myocardial cells in a healthy, normally functioning heart.
--The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.
--The atria, followed by the ven
The atria, followed by the ventricles, contract as a unit or they do not contract at all.
During contraction of heart muscle cells ________.
--calcium is prevented from entering cardiac fibers that have been stimulated
-- the action potential is initiated by voltage-gated slow calcium channels
--the action potential is prevented from spreading
some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells ________.
--tetanic contractions might occur, which would stop the heart's pumping action
--contractions would last as long as the refr
tetanic contractions might occur, which would stop the heart's pumping action
Compared to skeletal muscle, cardiac muscle ________.
has gap junctions that allow it to act as a functional syncytium
Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle
false
If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________.
decreased delivery of oxygen
which is true about cardiac output
--If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased.
--Stroke volume increases if end diastolic volume decreases.
--Decreased venous return will result i
A slow heart rate increases end diastolic volume, stroke volume, and force of contraction.
The second heart sound is heard during which phase of the cardiac cycle?
isvolumetric relaxation
The tricuspid valve is closed ________.
--when the ventricle is in systole
-- while the atrium is contracting
-- while the ventricle is in diastole
-- by the movement of blood from atrium to ventricle
when the ventricle is in systole
Normal heart sounds are caused by which of the following events?
Closing of the heart Valves
what is congestive heart failure?
The pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.
Is the Pulmonary trunk an artery or a vein?
ARTERY
Does the pulmonary truck carry oxygen rich or oxygen poor blood?
oxygen poor
Where are arteries connected to?
Ventricles
where are veins connected to?
atrium
The coronary sinus drains blood to the Left or Right atrium
Right atrium
Why does the coronary sinus drain blood to the right atrium and not the left?
Because it is still apart of the systemic system.
When is blood pumped into the coronary arteries?
When the aortic Semilunar valve is closed and the ventricle is in diastole
Papillary muscles function to
adjust tension of the chordae tendinae
which of the following has the thickest wall
Left ventricle
which vessle is in contact with myocardium
Loos areolar connective tissue
which of the following vessels contains oxygenated blood?
Inferior vena cava
superior vena cava
pulmonary arteries
pulmonary veins
pulmonary veins
What is the structure between right ventricle and pulmonary trunk?
pulmonary semilunar valves
What is the conduction pathway in the heart
SA node
AV node
Atrioventricular bundle
L&R bundle branches
purkinje fibers
During the cardiac cycle, the amount of blood ejected from the left ventricle when the semilunar valve opens is the
Stroke Volume
Which of the following is longer?
The refractory period of cardiac muscle or the refractory period of skeletal muscle?
The refractory period of cardiac muscle
if the papillary muscles fail to contract
The ventricles will not pump blood
the atria will not pump blood
the semilunar valves will not open
the AV valves will not open
None of these
None of these
when the semilunar valves are opened which of the following are occuring?
coronary arteries fill
AV valves are closed
Ventricles are in systole
Ventricles are in diastole
Blood enters aorta
Blood enters pulmonary arteries
atria contract
AV valves are closed
Ventricles are in Diastole
Blood enters aorta
AV node is located on
Right atrium
The major ion channel which is responsible for the plateau phase of the contractile cell action potential is
Voltage gated SLOW Ca++ Channels
Cardiac cells are communicated with each other via
gap junctions
How does the Parasympathetic nervous system affect the Heart rate?
ACH opens ligand gated K+ channels
longer to reach threshold
slowed heart rate
What major ion channel is responsible for the depolarization phase of the action potential of the conducting cells?
FAST voltage gated Ca++ channels
How does the Sypmathetic nervous system affect the heart rate?
NE opens more ligand gated Na+ channels
faster to reach threshold
heart rate inclease
What does the P wave represent?
Atrial contraction
What does the QRS complex represent
ventricular contraction
What does the T wave represent?
ventricular relaxation
Tachycardia
>100 beats/min short T-P interval
Bradychardia
<60 beats/min longer R-R
Mitral Stenosis
valve is leaking, blood backflow, extra wide P wave
Atrial Fibrillation
no P wave
Decreased pumping effectiveness
Ventricular fibrillation
No QRS
missing rythym or pattern