Anatomy & Physiology II Lab, Ch. 18: Heart

Which of the following is true of cardiac muscle?

A. Cardiac muscle tissue has both an intracellular and extracellular source of Ca++. B. Cardiac muscle tissue has slow Ca++ voltage gates in the membrane that make cardiac muscle incapable of tetanus. C. In cardiac muscle tissue, excitation spreads from cell to cell via intercalated disks. D. Cardiac muscle tissue does not require nerve activity to stimulate a contraction. E. All of these are true of cardiac muscle.

Which of these statements about the coronary arteries is true?

A. The left coronary artery supplies the anterior wall of the heart and most of the left ventricle. B. The right coronary artery supplies most of the right ventricle. C. Blood flow through the coronary arteries is greatest during ventricular diastole (relaxation). D. A heart attack occurs if a coronary artery is blocked. E. All of these are true

Intercalated disks in cardiac muscle

A. are a type of gap junction. B. allow all of the muscle fibers in an area to contract at the same time. C. prevent the cells from pulling apart. D. reduce the electrical resistance between cells allowing APs to pass more easily from cell to cell. E. All of these are correct

Which of the following structures are able to spontaneous generate an action potential?

A. the sinoatrial node (SA Node) B. the atrioventricular node (AV Node) C. the atrioventricular bundle D. the right and left bundle branches E. All of the items can spontaneously generate an action potential.

Given these structures: 1) AV node 2) atrioventricular bundle 3) bundle branches 4) Purkinje fibers Arrange these parts of the conduction system of the heart in the correct order, as an action potential would pass through them.

AV node atrioventricular bundle bundle branches Purkinjie fibers 1, 2, 3, 4

In a normal electrocardiogram (ECG or EKG)

Both the QRS complex results from depolarization of the ventricles and the T wave

Cardiac muscle cells

Both twist when they contract and shorten when they contract are correct.

Which of these statements concerning the functional characteristics of the heart chambers is NOT correct

During ventricular diastole, the semilunar valves open

The pericardium, or pericardial sac

Is a double-layered, closed structure Anchors the heart in the mediastinum Has a tough fibrous connective tissue outer layer Has an inner layer of squamous epithelial cells E. Has all of these characteristic

Depolarization of the atria is shown as the ______________ on an EKG.

P wave

The contraction of the atria and beginning relaxation of the atria is shown as the ________ on an EKG

P-Q (or P-R) interval

All of ventricular cells depolarizing and then repolarizing are shown as the ___________ on an EKG.

Q-T interval

Depolarization of the ventricles is shown as the _________________ on an EKG.

QRS complex

The following is a list of vessels and structures that are associated with the heart. 1) right atrium 2) left atrium 3) right ventricle 4) left ventricle 5) superior & inferior vena cava 6) aorta 7) pulmonary artery 8) pulmonary vein 9) mitrial/bicuspid valve 10) tricuspid valve 11) pulmonary semilunar valve 12) aorta semilunar valve What is the correct order for the flow of blood entering the heart from the BODY and leaving for PULMONARY CIRCULATION?

Superior& inferior vena cava right atrium tricuspid valve right ventricle pulmonary semilunar valve pulmonary artery 5, 1, 10, 3, 11, 7

Which of these statements concerning the form and location of the heart are correct?

The apex is directed to the left, and deep to the fifth intercostal space

Melinda suffers from stenosis of the aortic semilunar valve. This will increase the rigidity of the valve making it hard to open. This increases the ________________ therefore ________________ the cardiac output

afterload; decreasing

Coronary arteries may become blocked

by a thrombus, producing a coronary thrombosis

As the impulse from the SA node spreads across the atria, it is prevented from stimulating the ventricles

by the fibrous cardiac skeleton

Which of these is NOT a characteristic of cardiac muscle?

can develop a significant oxygen debt

The blood vessels that supply oxygenated blood to the heart tissue itself are the

coronary arteries

A large groove that runs around the heart, and separates the atria from the ventricles is the

coronary sulcus

The layer of the heart wall that is the visceral pericardium is also called the

epicardium

Which of these statements concerning the normal pathway of blood flow is NOT correct

from the pulmonary veins to the right atrium

"2" delivers blood

from the right ventricle to the lungs

The atria of the heart

function primarily as reservoirs for blood collection

The specialized __________ in the intercalated disks allow cytoplasm to flow freely between adjacent cells.

gap junctions

All of the following are functions of the heart EXCEPT:

generation of the formed elements of the blood

The cardiac skeleton

has all of these characteristics

Action potentials in contractile cardiac muscle cells

involve voltage-gated calcium ion channels.

The right atrium

is the location of the pacemaker cells of a normal heart.

The thick middle layer of the heart, composed of cardiac muscle, is the

myocardium

Papillary muscles

prevent the backflow of blood into the atria during ventricular systole

Papillary muscles:

prevent the backflow of blood into the atria during ventricular systole

The aortic semilunar valve

prevents blood flow from the aorta to the left ventricle

The bicuspid (mitral) valve

prevents blood flow from the left ventricle to the left atrium

The pulmonary semilunar valve

prevents blood flow from the pulmonary artery to the right ventricle

The tricuspid valve

prevents blood flow from the right ventricle to the right atrium

In a normal heart, when the right ventricle contracts, it forces blood through the

pulmonary semilunar valve

Which of these is NOT one of the large veins carrying blood to the heart

pulmonary trunk

The following is a list of vessels and structures that are associated with the heart. 1) right atrium 2) left atrium 3) right ventricle 4) left ventricle 5) superior & inferior vena cava 6) aorta 7) pulmonary artery 8) pulmonary vein 9) mitrial/bicuspid valve 10) tricuspid valve 11) pulmonary semilunar valve 12) aorta semilunar valve What is the correct order for the flow of blood entering the heart from the LUNGS leaving for SYSTEMIC CIRCULATION (i.e. the body)?

pulmonary vein left atrium mitral/bicuspid valve left ventricle aorta semilunar valve aorta 8, 2, 9, 4, 12, 6

"5" recieves blood

recieves blood from the right atrium

Like skeletal muscle, cardiac muscle:

relies on calcium and ATP to contract

Papillary muscles are attached to the cusps of valves by thin, strong connective tissue strings called

the chordae tendineae

As a result of the long refractory period generated by __________, cardiac muscle can not exhibit __________.

the influx of calcium ions, tetanus (tetanic contractions)

If a valve is classified as stenosed

the opening is narrowed

The serous pericardium just internal to the fibrous pericardium is called

the parietal pericardium

The right side of the heart forces blood to flow

to the lungs

Which of these valves is found between the right atrium and the right ventricle

tricuspid valve