Heart and Vessels Final Exam Review
In which septum is it normal to find openings in the adult?
Atrioventricular Septum
The influx of which ion accounts for the plateau phase?
Calcium
Which is not important in preventing backflow of blood?
Endocardium
When closed, the left atrioventricular valve prevents backflow of blood into the
Left atrium
Tachycardia predisposes a person to inadequate coronary blood flow because
it reduces the time that the myocardium is relaxed enough to permit blood flow
What heart problem may be caused, ironically, by the body's attempt to protect itself from a streptococcal throat infection?
rheumatic heart disease
list the valves in the order through which the blood flows from the vena cava through the heart.
tricuspid, pulmonary semilunar, bicuspid, aortic semilunar
The pulmonary trunk and aorta are derived from which primitive heart structure?
truncus arteriosus
atrium
upper or receiving chamber of the heart that pumps blood into the lower chambers just prior to their contraction; the right atrium receives blood from the systemic circuit that flows into the right ventricle; the left atrium receives blood from the pulmonary circuit that flows into the left ventricle
aortic valve
valve located at the base of the aorta
Rank the following in order from the longest lasting to the shortest-lived condition in a normal cardiac cycle: (1) atria relaxed (2) ventricles contracting (3) AV valves open (4) semilunar valves closed
1, 4, 3, 2
Just before leaving the heart to go to the lungs, blood must pass through a smooth-walled region called the
Conus arteriosus
The ________ layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.
Endocardium
Autonomic innervation of the heart does which of the following?
Increases heart rate and force of contractions and decreases heart rate without changing force of contractions
In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?
It decreases.
Although the valve itself is located elsewhere, the best auscultation site for the left AV valve is
Near the apex of the heart in the fifth intercostal space
What is unique to cardiac muscle cells?
Only cardiac muscle is capable of autorhythmicity
Which component of the heart conduction system would have the slowest rate of firing?
Purkinje fibers
Which chamber initially receives blood from the systemic circuit?
Right atrium
In terms of oxygen content of the blood they transmit, left atrioventricular is to aortic semilunar as ____________ is to pulmonary semilunar.
Tricuspid
The inclusive period of time from the beginning of one heartbeat to the next is called
a cardiac cycle
autorhythmicity
ability of cardiac muscle to initiate its own electrical impulse that triggers the mechanical contraction that pumps blood at a fixed pace without nervous or endocrine control
The force the heart must overcome to pump blood is known as ________.
afterload
cardiac output (CO)
amount of blood pumped by each ventricle during one minute; equals HR multiplied by SV
What happens during ventricular diastole?
both ventricles fill with blood
Which primitive area of the heart will give rise to the right ventricle?
bulbus cordis
The myocardium is composed of
cardiac muscle tissue
atrioventricular septum
cardiac septum located between the atria and ventricles; atrioventricular valves are located here
The two tubes that eventually fuse to form the heart are referred to as the ________.
cardiogenic tubes
Which structures prevent the AV valves from everting and flipping into the atria when the ventricles contract?
chordae tendineae and papillary muscles
As the ventricles start to contract, the first heart sound ("lubb") signifies the
closing of the AV valves
The first heart sound represents which portion of the cardiac cycle?
closing of the atrioventricular valves
atrioventricular (AV) node
clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum; receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum
Specialized cardiac muscle fibers that transmit muscle impulses to the contractile muscle cells of the myocardium are an important part of the heart's
conduction system
autonomic tone
contractile state during resting cardiac activity produced by mild sympathetic and parasympathetic stimulation
Sympathetic and parasympathetic components of the autonomic nervous system that innervate the heart are collectively called the
coronary plexus
In the coronary circulation, all venous blood returns to the heart through the
coronary sinus
The QRS complex of a typical electrocardiogram (ECG) tracing denotes the beginning of
depolarization of the ventricles
cardiac notch
depression in the medial surface of the inferior lobe of the left lung where the apex of the heart is located
cardiac reserve
difference between maximum and resting CO
What are the three layers of the heart wall, in order from external to internal?
epicardium, myocardium, endocardium
In an ECG tracing, what might an unusually strong QRS complex indicate?
hypertrophy of the ventricular myocardium
The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?
isovolumic contraction
anterior interventricular artery
major branch of the left coronary artery that follows the anterior interventricular sulcus
Which potentially fatal heart problem is most like a stroke, or cerebrovascular accident?
myocardial infarction
cardiac cycle
period of time between the onset of atrial contraction (atrial systole) and ventricular relaxation
bulbus cordis
portion of the primitive heart tube that will eventually develop into the right ventricle
When a person's heart "skips a beat," what has most likely occurred?
premature ventricular contraction
baroreceptor reflex
autonomic reflex in which the cardiac centers monitor signals from the baroreceptor stretch receptors and regulate heart function based on blood flow
anterior cardiac veins
vessels that parallel the small cardiac arteries and drain the anterior surface of the right ventricle; bypass the coronary sinus and drain directly into the right atrium
The epicardium is also called the
visceral layer of the serous pericardium
What happens to preload when there is venous constriction in the veins?
It increases.
The myocardium would be the thickest in the ________.
Left ventricle
A type of heart murmur called mitral valve prolapse would most likely involve a defect in
the left chordae tendineae or papillary muscles
Arrange these components of the heart's conduction system in their sequence of activity, beginning with the pacemaker: (1) Purkinje fibers (2) AV node (3) SA node (4) AV bundle
3, 2, 4, 1
Which valve separates the left atrium from the left ventricle?
Mitral
If the fetal septum primum and septum secundum fail to fuse properly at birth, the newborn has a congenital heart malformation called
an atrial septal defect
The inferior, conical end of the heart is called the
apex
anastomosis
area where vessels unite to allow blood to circulate even if there may be partial blockage in another branch
As their name implies, the heart chambers that receive blood returning through both circulatory circuits are called
atria
Externally, the atria and ventricles are separated by a relatively deep groove called the
coronary sulcus
auricle
extension of an atrium visible on the superior surface of the heart
The serous pericardium does not
form a mucous membrane lining the pericardial cav
After birth, the foramen ovale of the fetal heart is replaced by a small depression in the interatrial septum called the
fossa ovalis
Bachmann's bundle
group of specialized conducting cells that transmit the impulse directly from the SA node in the right atrium to the left atrium
The earliest organ to form and begin function within the developing human is the ________.
heart
artificial pacemaker
medical device that transmits electrical signals to the heart to ensure that it contracts and pumps blood to the body
The cardiovascular centers are located in which area of the brain?
medulla oblongata
Of the three germ layers that give rise to all adult tissues and organs, which gives rise to the heart?
mesoderm
cardiac reflexes
series of autonomic reflexes that enable the cardiovascular centers to regulate heart function based upon sensory information from a variety of visceral sensors
The cardiac muscle fibers of the ____________ act as the pacemaker, the rhythmic center that initiates the heartbeat.
sinoatrial node
Oxygenated blood returning from the lungs enters the left atrium through
the pulmonary veins
bicuspid valve
valve located between the left atrium and ventricle; consists of two flaps of tissue
What ensures the unidirectional flow of blood through both the heart and the blood vessels?
valves within the heart that prevent backflow of blood
immediately follows ________.
ventricular repolarization
afterload
Force the ventricles must develop to effectively pump blood against the resistance in the vessels
The heart is rotated such that the ____________ are located more anteriorly, while the other chambers are located more posteriorly.
Right atrium and ventricle
atrioventricular bundle branches
Specialized myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the interventricular septum; lead to the Purkinje fibers and also to the right papillary muscle via the moderator band
Blood from the systemic circuit returns to the right atrium through
The superior vena cava, the inferior vena cava and the coronary sinus
Oxygenated blood flows through ____________ in the systemic circuit but through ____________ and the opposite heart chambers in the pulmonary circuit.
arteries and the left atrium and ventricle; veins
Most blood enters the ventricle during ________.
atrial diastole
Which set correctly lists the sequence in which events in the cardiac cycle begin?
atrial systole, atrial diastole, ventricular systole, ventricular diastole
Bainbridge reflex
autonomic reflex that responds to stretch receptors in the atria that send impulses to the cardioaccelerator area to increase HR when venous flow into the atria increases
atrial reflex
autonomic reflex that responds to stretch receptors in the atria that send impulses to the cardioaccelerator area to increase HR when venous flow into the atria increases
atrioventricular bundle
group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches
bundle of His
group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches
An ECG produces a composite tracing of all ____________ generated by myocardial cells.
muscle impulses
atrioventricular valves
one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve
cardiac plexus
paired complex network of nerve fibers near the base of the heart that receive sympathetic and parasympathetic stimulations to regulate HR
What are the prominent ridges on the internal surfaces of the auricles and the anterior atrial walls?
pectinate muscles
The fibrous skeleton of the heart does not
promote random impulse conduction throughout the heart wall
Blood from the systemic circuit returns directly into which heart chamber?
right atrium
The right coronary artery typically branches into which two vessels?
right marginal artery and posterior interventricular artery
From the right atrium, blood passes through the right AV (tricuspid) valve into the
right ventricle
The pulmonary trunk carries blood from which heart chamber into the pulmonary circuit?
right ventricle
anterior interventricular sulcus
sulcus located between the left and right ventricles on the anterior surface of the heart
The ____________ carries blood throughout the body; the ____________ carries blood only to and from the lungs.
systemic circuit; pulmonary circuit
Regardless of the heart chamber, contraction is called ____________ and relaxation, ____________.
systole, diastole
Under normal conditions, only two heart chambers are ever concurrently in ____________, but all four are ____________ together for the last half of the cardiac cycle.
systole; relaxing
What would happen if the papillary muscles could not contract?
the atrioventricular valves would not seal tightly
