Chapter 20
Systole
Contraction of the heart
What vessels empty into the right atrium? Select all that apply.
Coronary sinus Superior vena cava Inferior vena cava
Which structures allow the entire myocardium of both ventricles to contract as a unit?
Gap junctions
Identify the functions of the heart.
Generates blood pressure Separates pulmonary and systemic circulations Moves blood in one direction
What vessels empty into the left atrium?
Left pulmonary veins Right pulmonary veins
What segment of an ECG does atrial systole occur?
PR interval
The right and left coronary arteries arise from the
aorta
The vessel that carries blood out of the left ventricle is the
aorta
Anastomoses are direct connections between
arteries
endocardium
inner lining of the heart
The fossa ovalis is a depression in the
interatrial septum
The upper chambers of the heart are divided from each other by the ...
interatrial septum
Regulation that results from the heart's normal functional characteristics and does not depend on neural or hormonal regulation is called....
intrinsic regulation
The phase of the cardiac cycle during which the ventricles are contracting, but all valves remained closed is called
isovolumetric contraction
visceral pericardium
layer closest to the heart
The foramen ovale is an opening between the
left and right atrium What structure allows blood to flow between the atria in the embryo and fetus?
The average pressure in the arteries is the
mean arterial pressure
Cardiac Output X Peripheral Resistance
mean arterial pressure / MAP
Cardiac muscle cells have an abundance of ............., an organelle that carries out aerobic metabolism to generate ATP.
mitochondria
The alternate name for the left atrioventricular valve is the
mitral/bicuspid
Myocardium The layer of the heart wall that gives it the ability to contract is called the
muscular, middle layer of the heart
epicardium
outer layer of the heart
parietal pericardium
outer layer of the pericardium
The structures that contract and prevent the AV valves from moving backward into the atria are called
papillary muscles
The internal ridges of myocardium found in the right atrium and auricle are the
pectinate muscles
The double-walled sac enclosing the heart is called the
pericardium
The phase of the cardiac cycle called Blank______ begins when ventricular pressure exceeds arterial pressure.
period of ejection
in the plateau phase of a cardiac muscle cells, Blank______ moves out of the cell.
potassium
At rest, what ion is abundant inside of the cardiac cell membrane, helping to establish the resting membrane potential?
potassium k+
The refractory period that is the time when the muscle cell requires greater stimulation for generation of an action potential is the........ refractory period.
relative
What does the small cardiac vein drain?
right atrium and right ventricle
The movement of calcium into a cardiac muscle cell through the membrane results in calcium release from the
sarcoplasmic reticulum
The valves that prevent backflow into the ventricles are called
seminar
the second heart sound is associated with the closing of the Blank______ valves.
semiulnar
The group of cells located in the right atrium that act as a pacemaker for the heart is called the
sinoatrial
The relationship between preload and stroke volume is referred to as the ...law of the heart.
starling
An increase in contractility caused by the sympathetic stimulation will result in increased
stroke volume
Cardiac output is equal to....... times heart rate.
stroke volume
circumflex artery
supplies the left atrium and the posterior walls of the left ventricle
The third heart sound is produced by
turbulent flow
bicuspid valve
valve between the left atrium and the left ventricle.
tricuspid valve
valve between the right atrium and the right ventricle
The amount of blood returning to the heart from the systemic circulation is called
venous return
The term "dicrotic" means
double beating
The blood vessel that collects venous drainage from the left side of the heart and travels alongside the anterior interventricular artery is the
great cardiac vein
T-tubules of cardiac muscles are found
near z disks of sarcomeres
right marginal artery
serves the myocardium of the lateral right side of the heart
The pacemaker of the heart is typically the
sinus
arrhythmia
Abnormal heart rhythm
What are the functions of the fibrous skeleton?
Anchors cardiac muscle Provides structural support for the heart Provides electrical insulation between the atria and ventricles
Identify the branches of the left coronary artery.
Anterior interventricular artery. Left marginal artery Circumflex artery
Identify the events that occur during ventricular systole.
Blood moves from ventricles through semilunar valves. Ventricles contract.
Which groove encircles the heart, separating the atria from the ventricles?
Coronary sulcus
serous pericardium
Delicate membrane around the heart consisting of the parietal and visceral layer. 2 layered
Indicate the type of junctions found at intercalated discs.
Desmosomes Gap junctions
Ventricular systole occurs completely during which indicated region of the ECG?
E, QT
Identify the characteristics of cardiac muscle cells.
Elongated, branching cells Organized myofilaments Intercalated discs between cells
base
Flat, superior end of the heart that lies deep to the sternum and extends to the second intercostal space
Identify the events that occur during ventricular diastole.
Isovolumetric relaxation Ventricular filling
Shape of heart The adult heart weighs an average of ______ grams.
Larger in males than females Size of closed fist 250-300 grams
Atrial repolarization occurs during the
QRS complex
The wave of an ECG that is a recording of the repolarization of the ventricular myocardium is the
T wave
What is the relationship between the heart and the adrenal medulla?
The adrenal medulla influences the action of the heart.
apex
The blunt, rounded point of the heart oriented to the left of the sternum
What valves are closing during the first heart sound?
Tricuspid Bicuspid
The epicardium is also called what?
Visceral pericardium
The refractory period that is the time when the muscle cell cannot be further stimulated, no matter the strength of the stimulus is the...... refractory period.
absolute
papillary muscles
anchor the chordae tendineae to the ventricular wall.
The groove that extends downward from the coronary sulcus on the front of the heart is the
anterior interventricular sulcus
Afterload is the amount of pressure needed to move blood into the
aorta
The posterior interventricular sulcus extends from the coronary sulcus toward the ______ of the heart.
apex
The inferior end of the heart that tapers to a blunt point immediately above the diaphragm is called the..... of the heart and the larger, flat end of the heart that lies deep to the sternum is called the ........
apex, base
Atrioventricular valves ensure one-way blood flow from
atria to ventricles
The valves that separate the upper and lower chambers of the heart are called Blank______ valves.
atrioventricular
The flaplike extension of each atrium is called a(n)
auricle
The cardioregulatory center sends information to the heart through Blank
automnic nervous system
Altered blood pressure can lead to changes in heart rate. The input for this reflex response is from the Blank______ of the large arteries, which monitor blood pressure changes.
baroreceptors
What is the volume of blood ejected by the ventricles per minute called?
cardiac output
The difference between the maximum cardiac output and resting cardiac output is known as the
cardiac reserve
An organ or cell specialized to detect chemicals is classified as a
chemoreceptor
systemic circulation
circulation that supplies blood to all the body except to the lungs
The blood vessels that supply nutrients and oxygen only to the heart muscle make up the specific type of circulation called the ______ circulation.
coronary
The three vessels that return deoxygenated blood to the right atrium are the ..........veins and the superior and inferior...........
coronary ; vena cava
The expanded blood vessel indicated in the figure is the
coronary sinus
The ridge that separates the pectinate muscles from the smoother part of the atrial wall is called the ...... terminalis.
crista
The stroke volume is equal to the end- volume minus the end- volume
diastolic, systolic
If another region of the heart other than the SA generates a heartbeat, this region is called a(n)....... focus.
ectopic
The volume of blood remaining in the ventricles at the end of ventricular contraction is called - volume
end systolic
The three layers of the heart wall from deep to superficial are the
endocardium myocardium epicardium
Regulation of the heart that involves neural or hormonal control is called ... regulation.
extrinsic
Purkinje fibers
fibers in the ventricles that transmit impulses to the right and left ventricles, causing them to contract
The framework of collagenous and elastic fibers found in the walls between chambers form the
fibrous skeleton
pulmonary circulation
flow of blood from the heart to the lungs and back to the heart
Electrical insulation between atria and ventricles is one function of the
heart skeleton
Put the following in order as seen on a standard ECG trace.
AD P VD QRS VR T
dicrotic notch
brief rise in aortic pressure caused by backflow of blood rebounding off semilunar valves
The atrioventricular ........(one word) is an electrical pathway by which signals leave the AV node to move to the interventricular septum
bundle
Sarcoplasmic reticulum of cardiac muscle stores
calcium
The ion primarily responsible for depolarization in pacemaker cells is
calcium
The Blank______ is a repeating series of contraction and relaxation events that move blood through the heart.
cardiac cycle
ventricular diastole
the period between ventricular contractions when the ventricles are repolarizing
The heart is located in the mediastinum, which is an area of the ______ cavity.
thoracic cavity
fibrous pericardium
tough, white fibrous connective tissue that is the outer layer of the pericardium
The internal ridges of myocardium seen in the ventricles are called ......... carneae.
trabeculae
