Bio 228 Ch. 19
Contraction of the atrial myocardium is called __________.
atrial systole
The __________ is the ability to reach threshold without stimulation.
pacemaker potential
The delivery of blood per unit time per gram of tissue is called ________. 1) ventilation 2) contraction 3) circulation 4) perfusion
perfusion
A __________ agent is one that results in an increase in the heart rate.
positive chronotropic
During the refractory period, cardiac muscle __________. 1) cannot be restimulated 2) needs a stronger stimulus to be stimulated
cannot be restimulated
The volume of blood pumped by one ventricle in one minute is defined as __________.
cardiac output
Parasympathetic innervation of the heart comes from the __________ via the left and right vagus nerves.
cardioinhibitory center
Many cases of sudden cardiac death can be attributed to ________ which results from congenital defects and coronary artery abnormalities
cardiomegaly
In the right ventricle, papillary muscles anchor thin strands of collagen fibers called ________.
chordae tendineae
During the period of ejection in the cardiac cycle, the AV valves are ________ and the semilunar valves are _________.
closed open
The coronary vessels are ________ when the heart contracts which ________ blood flow.
compressed impedes
The __________ deliver oxygen rich blood to the thick heart wall while the __________ carry deoxygenated blood away from the heart wall.
coronary arteries coronary veins
All cardiac veins empty into the ________, which then empties into the ________.
coronary sinus right atrium
Structures in cardiac muscle cells are ________, ________, ________, and ________.
desmosomes gap junctions smooth sarcoplasmic reticulum T tubules
__________ contraction is the beginning of the ventricular contraction.
Isovolumetric
The ________ of the heart receive blood and the ________ pump blood to the lungs and body tissues.
atria ventricles
The fibrous skeleton of the heart is located between the ________ and the ________.
atria ventricles
The heart is innervated by the ________ nervous system.
autonomic
A(n) ________ refers to the cells outside of the SA node that controls the heart rate.
ectopic pacemaker
Prolonged pumping of unequal amounts of blood by the left and right ventricles can lead to ________.
edema
During ventricular ________ blood moves from the ventricles into the pulmonary trunk and aorta.
ejection
A function of the fibrous skeleton is to provide ________ insulation between atria and ventricles.
electrical
The amount of blood in the ventricles immediately prior to initiation of contraction is called __________.
end diastolic volume (EDV)
The atrial reflex is initiated when ________ in the atrial walls are stimulated by an increase in venous return.
baroreceptors
This occurs at the same time as atrial systole:
blood is being pumped into the ventricles
The second heart sound, "dupp" is heard when the seminlunar valves close, and this is related to the ________ on an ECG.
end of the T wave
Factors that result in an increase in venous return include ________ and a ________ heart rate.
exercise decreased
As we age, ________ is deposited in the epicardium, and so this layer becomes ________.
fat thicker
During atrial contraction the atria are contracting and the ventricles are ________.
filling
Late ventricular relaxation is an important time for ventricular ________.
filling
An opening in the septum secundum (which is covered by the septum primum) is called the __________.
foramen ovale
Since it's the right side of the heart that sends blood to the lungs, blood is shunted from the right atrium to the left atrium by traveling through the ________ and pushing the septum primum to the ________.
foramen ovale left
Intercalated discs include these structures:
gap junctions, desmosomes, interdigitating folds
Within the intercalated discs, junctions increase the flow of ions between the cells as the muscle impulse moves along the ________.
gap/sarcolemma
Cardiac muscle can use fatty acids, ________, lactic acid, amino acids and ________ bodies as fuel sources.
glucose ketone
The 3 main components of the cardiovascular system are ________, ________, and ________.
heart blood vessels blood
Coronary arteries are considered functional end arteries and not anastomoses because __________.
if one becomes blocked there is insufficient blood flow to the tissue.
Increase venous return = ________ stroke volume.
increase
When heart rate and stroke volume increase, cardiac output ________.
increases
The effect of norepinephrine on the heart: 1) increases the rate and strength of contraction 2) decreases the rate and strength of contraction 3) decreases the amount of blood pumped per minute
increases the rate and strength of contraction
Inotropic agents increase stroke volume by __________. 1) increasing contractility 2) increasing Ca2+ levels 3) decreasing Ca2+ levels
increasing contractility increasing Ca2+ levels
Gap junctions increase the flow of ________ between the cells as the muscle impulse moves along the sarcolemma.
ions
The __________ contraction phase of the cardiac cycle includes closure of the AV and semilunar valves even though the Purkinje fibers have initiated __________ contraction.
isovolumetric ventricular
The circumflex artery supplies blood to the ________ ventricle.
left
In an atrial septal defect, the postnatal heart still has an opening between the left and right atria. Thus, blood from the ________ atrium is shunted to the ________ atrium.
left right
The systemic circulation is movement of blood from the ________ side of the heart to the systemic cells of the body and back to the ________ side of the heart.
left right
The right coronary artery typically branches into the right ________ artery, which supplies the lateral wall of the right ventricle, and the posterior ________ artery, which supplies the posterior surface of both the left and right ventricles.
marginal interventricular
The heart is located in the ________, which is located in the ________.
mediastinum thoracic cavity
Damage to this part of the brain would cause the body to have less control over cardiac activity:
medulla oblongata
The __________ agents decrease heart rate by causing hyperpolarization of the cell membrane potential.
negative chronotropic
The __________ contract and anchor the chordae tendineae to the AV valve cusps.
papillary muscles
The cone shaped muscular projections of the right ventricular wall are called ________.
papillary muscles
The posterior atrial wall is smooth, but the auricle and anterior wall exhibit obvious muscular ridges called ________.
pectinate muscles
An agent that causes an increase in stroke volume is known as a __________ agent.
positive inotropic
The common atrium is subdivided into a left and right atrium by an interatrial septum, which consists of two parts; the septum ________ and the septum ________ that partially overlap.
primum secundum
The __________ carries blood away from the right ventricle and branches into the pulmonary arteries
pulmonary arteries
The coronary sinus drains directly into the ________ atrium of the heart.
right
The opening for the coronary sinus is located in the wall of the __________.
right atrium
The epicardium is also known as the __________.
visceral pericardium
In cardiac muscle cells, rapid depolarization is caused by the opening of this: 1) voltage-gated Ca2+ ion channels 2) voltage-gated Na+ ion channels 3) voltage-gated K+ ion channels
voltage-gated Na+ ion channels
Rheumatic heart disease can cause ________. 1) valvular stenosis 2) aortic dissection 3) valvular insufficiency
valvular stenosis
The ________ ions must bind to troponin to allow the cross bridge cycling to begin.
calcium
Place in the correct order the sequence of events resulting in the action potential for cardiac muscle cells. -Na+ ions enter causing depolarization -Depolarization causes opening of voltage-gated K+ channels -Plateau occurs -Voltage-gated Ca2+ channels close -Repolarization occurs, returning the cell to the resting membrane portential -Slow voltage-gated Ca2+ channels open causing a Ca2+-induced Ca2+ release
-Na+ ions enter causing depolarization -Depolarization causes opening of voltage-gated K+ channels -Slow voltage-gated Ca2+ channels open causing a Ca2+-induced Ca2+ release -Plateau occurs -Voltage-gated Ca2+ channels close -Repolarization occurs, returning the cell to the resting membrane portential
Correct order of the initiation and conduction of an action potential through the heart. -SA node fires action potential -Action potential reaches AV node via gap junctions -Action potential travels up the Purkinje fibers -Action potential is delayed at the AV node -Actions potential travels down the bundle branches
-SA node fires action potential -Action potential reaches AV node via gap junctions -Action potential is delayed at the AV node -Actions potential travels down the bundle branches -Action potential travels up the Purkinje fibers
The epicardium is composed of simple squamous epithelium and ________ connective tissue. 1) reticular 2) dense 3) areolar
areolar
The left ventricle normally has _____ papillary muscles.
2
Place the options in the correct order for the opening of ion channels in a cardiac nodal cell from resting membrane potential through an action potential. 1) Fast voltage-gated Ca2+ channels 2) Voltage-gated K+ channels 3) Slow voltage-gated Na+ channels
3,1,2 Slow voltage-gated Na+ channels Fast voltage-gated Ca2+ channels Voltage-gated K+ channels
In order, an action potential passes through: 1) AV bundle 2) AV node 3) bundle branches 4) Purkinje fibers 5) SA node
5,2,1,3,4 SA node AV node AV bundle bundle branches Purkinje fibers
The normal rate of spontaneous depolarization of the SA node: 1) 20-40 per minute 2) 40-60 per minute 3) 70-80 per minute 4) over 100 per minute
70-80 per minute
After initiation, the muscle impulse travels from the SA node to the __________.
AV node
The AV node is located in the floor of the right atrium between the right ________ and the opening for the ________.
AV valve coronary sinus
__________ do(es) not contribute to the ability of cardiac muscle to meet its energy demands. 1) An extensive blood supply 2) Glycolytic enzymes 3) Myoglobin 4) Numerous mitochondria
Glycolytic enzymes
HR x SV =
CO (cardiac output)
__________ cells cannot exhibit tetany. 1) Skeletal cells 2) Cardiac cells
Cardiac cells
__________ is a measure of how effective the cardiovascular system is in fulfilling its function in transporting life supporting substances through the body.
Cardiac output
Atrial contraction causes which to occur? 1) Compresses the openings of the great veins 2) Causes closure of the semilunar valves 3) Pushes blood into ventricles
Compresses the openings of the great veins Pushes blood into the ventricles
SV = _____ - _____
EDV ESV
True or False: All arteries carry oxygenated blood.
False
True or False: Papillary muscles are associated with semilunar valves.
False
Movement of _____ is responsible for the depolarization phase of the action potential in cardiac muscle cells.
Na+
Which options are involved in establishing and maintaining the resting membrane potential in cardiac node cells? 1) Na+/K+ pumps 2) K+ leak channels 3) Cl- leak channels 4) Na+ leak channels
Na+/K+ pumps K+ leak channels Na+ leak channels
The _____ wave reflects the electrical changes of atrial depolarization.
P
On an ECG, the AV node is not conducting action potentials when the _____ wave and QRS complex are not ________.
P synchronized
The ________ valves are closed in the isovolumetric phase of the cardiac cycle.
Pulmonary semilunar Bicuspid Tricuspid
The left and right bundles conduct the impulse from the AV bundle to conduction fibers called __________.
Purkinje fibers
From the beginning of ventricular depolarization to the end of ventricular repolarization corresponds to which ECG component?
Q-T interval
At which point on an ECG is the first heart sound, "lubb", heard?
QRS complex
The segment that is associated with ventricular contraction is _____.
S-T
The single heart tube develops into what 4 structures? 1) Sinus venosus 2) Inferior vena cava 3) Primitive ventricle 4) Primitive atrium 5) Superior vena cava 6) Bulbus cordis
Sinus venosus Primitive ventricle Primitive atrium Bulbus cordis
What are the great vessels?
Superior vena cava Inferior vena cava Aorta
Which options are part of the cardiac muscle cells? 1) T tubules 2) Sarcolemma 3) Fasciculi 4) Myofibrils
T tubules Sarcolemma Myofibrils
True or False: Afterload is the pressure that the heart must work against to pump blood into the systemic circulation.
True
True or False: Relaxation of the atrial muscle is necessary for the cardiac veins to return blood to the atria.
True
True or False: The innervation by autonomic centers in the brainstem does not initiate a heartbeat, but it can increase of decrease the rate of the heartbeat.
True
In a person who has a damaged left ventricle due to a heart attack, they would experience this: 1) left ventricle pumps less blood than the right 2) blood accumulates in the pulmonary vessels 3) blood accumulates in the systemic vessels
a & b left ventricle pumps less blood than the right & blood accumulates in the pulmonary vessels
Cardiac reserve is an increase in cardiac output above its level at rest. Therefore a trained athlete would be expected to have ________ compared to a non-athlete. 1) no advantage in the ability to increase cardiac output 2) a greater ability to increase the cardiac output
a greater ability to increase the cardiac output
The resting membrane potential (RMP) depends upon this: 1) low permeability to Na 2) high permeability to K 3) low permeability to Ca
all of these
The coronary arteries are considered functional end arteries because their ________ shunt too little blood from one artery to the other.
anastomoses
The condition, __________ is characterized by poorly localized pain in the left side of the chest, left arm, and shoulder. It can result from strenuous activity and is temporary.
angina pectoris
The entrance into the ________ is located at the superior aspect of the left ventricle.
aorta
During isovolumetric relaxation, the ________ valves close to prevent blood backflow into the ventricles.
semilunar
The second heart sound is produced when the ________ valves close, producing a "dupp" sound.
semilunar
The __________ and the primitive atrium form parts of the left and right atria. 1) bulbus cordis 2) ductus arteriosus 3) sinus venosus
sinus venosus
An infant's heart rate is higher than an adult's because the smaller heart = a ________ stroke volume
smaller
The amount of blood that leaves the heart during ventricular contraction is called the __________.
stroke volume
The right atrium receives venous blood from the ________.
superior and inferior vena cava
The three major vessels that empty into the right atrium: ________, ________, and ________.
superior vena cava inferior vena cava coronary sinus
The purpose for the delay in the conduction of the action potential from the AV node to the bundle branches of the ventricles is to allow __________. 1) the atria to complete their contraction 2) the pulmonary valves to close 3) the atria to complete their filling
the atria to complete their contraction
Each semilunar valve is composed of ________ thin, ________ shaped, pocket like semilunar cusps.
three half-moon
The bulbus cordis may be further subdivided into a ________ part of the right ventricle, which forms most of the right ventricle.
trabeculated
