CH 20. The Heart

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

Blood is supplied to the myocardium by

the coronary arteries

Activation of which kind of receptor causes heart rate to increase?

beta-one

When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n)

coronary thrombosis

In cardiac muscle, the fast depolarization phase of the action potential is the result of

increased membrane permeability to sodium ions.

Rupture of the papillary muscles in the left ventricle may result in

mitral valve prolapse

Each of the following factors will increase cardiac output except increased

parasympathetic stimulation True: -force of contraction. -heart rate. -sympathetic stimulation. -venous return.

Stroke volume depends on all of the following factors except

respiratory rate. True: -venous return of blood to the heart. -the pressure required to pump blood into the aorta. -end diastolic volume -the contractility of the ventricle.

What feature allows the blood supply to the heart muscle to remain relatively constant regardless of the pressure changes in the coronary arteries due to heartbeats?

arterial anastomoses

The property of heart muscle to contract in the absence of neural or hormonal stimulation is called

automaticity

The long plateau phase of the cardiac muscle action potential is due to

calcium channels remaining open.

The amount of blood pumped by the left ventricle in one minute during the cardiac cycle is called the __________.

cardiac output

The cusps (leaflets) of atrioventricular valves attach directly to

chordae tendineae

As blood leaves the right ventricle, it passes through the ________ and then into the pulmonary trunk.

conus arteriosus

A procedure in which a length of the patient's vein or artery is used to create a detour around an obstruction in a coronary artery is called

coronary artery bypass graft

The amount of blood remaining in the ventricle when the semilunar valve closes is the

end-systolic volume.

________ is when the heart can't maintain adequate cardiac output.

heart failure

Blood returning to the heart from the pulmonary circuit first enters the

left atrium

An MI that affects the ________ side of the heart is more severe because it has to pump blood with ________ force.

left; more

Abnormal heart sounds caused by turbulent flow through faulty valves are called

murmurs

Contractions of the papillary muscles

prevent the atrioventricular valves from reversing into the atria.

Blood leaves the right ventricle by passing through the

pulmonary valve

Blood returning to the heart from the systemic circuit first enters the

right atrium

Coronary veins empty into the

right atrium

The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the

systolic ejection phase.

The normal pacemaker of the heart is located in

the sinoatrial node.

If the connection between the SA node and AV node becomes blocked,

the ventricles will beat more slowly.

Muscular ridges on the inner surface of the ventricles are called

trabeculae carneae

If the force of ventricular contraction increases, what will happen to the end-systolic volume?

decrease (ventricle won't have chance to fill as much)

John encounters a bear while hiking. His heart will respond in all of the following ways except

decreasing heart rate and contractility. True: -increasing venous return. -increasing contractility. -increasing preload. -increasing heart rate.

Which of the following describes what is directly measured by an ECG?

electrical conduction

The ________ is the volume of blood in a ventricle at the beginning of systole.

end-diastole volume

The ________ is the amount of blood in a ventricle after it has contracted and before it begins to refill.

end-systolic volume

An action potential in cardiac contractile cells is the same as an action potential in skeletal muscle cells EXCEPT for ______.

the presence of a plateau phase in cardiac contractile cells True: -the movement of potassium ions out of the cell during repolarization -at threshold, voltage-gated sodium channels open, and there is a massive influx of sodium ions -as the membrane potential approaches +30mV, the voltage-gated sodium channels close, and sodium begins to be actively transported out of the cell

Tetanic muscle contractions don't occur in a normal cardiac muscle because

the refractory period lasts until the muscle relaxes.

Cardiac cells damaged by infarction will show all of the following except

an increase in metabolic activity True: -release of enzymes into the circulation. -a switch to anaerobic metabolism -release of CK-MB into the circulation. -release of troponin T and I into the circulation.


Kaugnay na mga set ng pag-aaral

WHAP Final, WHAP Review Part 4, WHAP Review Part 3, WHAP Final Review Part 2, WHAP Unit 8 Test, WHAP Test 07, WHAP Study Guide, Unit 6, WHAP EXAM

View Set

AAMC Bundle Practice Exam 1 - Questions I missed/to review

View Set

Sloveso + prepozice s akuzativem

View Set

ATI Care of Children Online Practice 2019 A with NGN

View Set

Chapter 13 Accounting Concept Assessments

View Set

Art I: The Elements and Principles of Art U2L15

View Set