Chapter 19 - The Cardiovascular System: The Heart

Which of the following is not important in preventing backflow of blood?

A. Chrodae tendineae

B. Papillary Muscles

C. AV Valves

D. Endocardium

D. Endocardium

Chrodae Tendineae

These are "tendinous cords," or sometimes more poetically referred to as "heart strings.". They are composed of approximately 80 percent collagenous fibers with the remainder consisting of elastic fibers and endothelium.

Papillary Muscles

Connected to the Chrodae Tendineae, there are three of these muscles called the: anterior,posterior, and septal muscles, which correspond to the three sections of the valves.

AV Valves

Valves between atria and ventricles. "Atrioventricular". It is marked by the presence of four openings that allow blood to move from the atria into the ventricles and from the ventricles into the pulmonary trunk and aorta.

Endocardium

Inner layer of the heart. Tissue.

What valve separates the left atrium from the left ventricle?

Mitral

Which of the following lists the valves in the order through which the blood flows from the vena cava through the heart?

A. Tricuspid, pulmonary semilunar, bicuspid, aortic semilunar

B. Mitral, pulmonary semilunar, bicuspid, aortic semilunar

C. Aortic semilunar, pulmonary semilunar, tricuspid, biscupid

D. Biscupid, aortic semilunar, tricuspid, pulmonary semilunar

A. Tricuspid, pulmonary semilunar, bicuspid, aortic semilunar

What chamber initially receives blood from the systemic circuit?

Right atrium

The ________ layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.

Endocardium

The myocardium would be the thickest in the ________.

Left ventricle

In which septum is it normal to find openings in the adult?

Atrioventricular septum

Interatrial Septum

This is the partition between the right and left atria. "Bachmann's bundle".

Interventricular Septum

This is the partition between the right and left ventricles. The two openings that are connected to third ventricle.

Which of the following is unique to cardiac muscle cells?

A. Only cardiac muscle contains a sarcoplasmic reticulum.

B. Only cardiac muscle has gap junctions.

C. Only cardiac muscle is capable of autorhythmicity.

D. Only cardiac muscle has a high concentration of mitochondria.

C. Only cardiac muscle is capable of autorhythmicity.

The influx of which ion accounts for the plateau phase?

Calcium

Which portion of the ECG corresponds to repolarization of the atria?

QRS Complex

QRS Complex

This represents the depolarization of the ventricles, which requires a much stronger electrical signal because of the larger size of the ventricular cardiac muscle.

P-Wave

Represents the depolarization of the atria.

T-Wave

Represents the repolarization of the ventricles.

Which component of the heart conduction system would have the slowest rate of firing?

Purkinje Fibers

Atrioventricular Node

A component in the cardiac conduction system. A second clump of specialized myocardial conductive cells, located in the inferior portion of the right atrium within the atrioventricular septum.

Atrioventricular Bundle

"Bundle of His"; specialized muscle fibers connecting the atria with the ventricles and transmitting electrical impulses between them.

Bundle Branches

Branches off the Bundle of His that conduct impulses to the left and right ventricles. commonly called the left and right bundle branches.

Purkinje Fibers

Additional myocardial conductive fibers that spread the impulse to the myocardial contractile cells in the ventricles.

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?

Diastole

Diastole

The period of relaxation that occurs as the chambers fill with blood.

Systole

The period of contraction that the heart undergoes while it pumps blood into circulation.

Most blood enters the ventricle during ________.

Atrial Diastole

The first heart sound represents which portion of the cardiac cycle?

Atrial Systole

Ventricular relaxation immediately follows ________.

Ventricular repolarization

Repolarization

Return of the membrane potential to its normally negative voltage at the end of the action potential.

Depolarization

Change in a cell membrane potential from rest toward zero.

The force the heart must overcome to pump blood is known as ________.

Afterload

Preload

The volume of blood in ventricles at end of diastole.

The cardiovascular centers are located in which area of the brain?

Medulla Oblongata

In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?

It decreases.

What happens to preload when there is venous constriction in the veins?

It increases.

Which of the following is a positive inotrope?

A. Na+

B. K+

C. Ca2+

D. Both Na+ and K+

C. Ca2+

The earliest organ to form and begin function within the developing human is the ________.

Heart

Of the three germ layers that give rise to all adult tissues and organs, which gives rise to the heart?

Mesoderm.

Ectoderm

It develops into the integumentary system (the skin) and the nervous system. The pituitary gland and the pineal gland arises from this germ layer.

Endoderm

Lining of airways and diestive system except the mouth and distal part of digestive system. It gives rise to the thyroid and parathyroid glands, as well as the pancreas and the thymus.

The two tubes that eventually fuse to form the heart are referred to as the ________.

Endocardial Tubes

Which primitive area of the heart will give rise to the right ventricle?

Bulbus Cordis

The pulmonary trunk and aorta are derived from which primitive heart structure?

Truncus Arteriosus