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