A&P2 Ch.20 mastering part a

The heart beats approximately ________ times each day.

100,000

Which chamber receives oxygenated blood from the pulmonary circuit?

16

The ________ valve prevents backward flow into the left atrium.

Bicuspid

________ is to slow heart rate as ________ is to fast heart rate.

Bradycardia; tachycardia

During the plateau phase of the cardiac action potential which ion is entering the cardiac muscle cell?

Calcium

Pacemaker cells in the SA node

Can spontaneously depolarize

Which of the following will receive electrical impulses next after the structure indicated by the red arrow?

Interventricular septum

When the semilunar valves close the AV valves then

Open

Depolarization of the atria corresponds to the EKG's

P wave

Identify the structure labeled "8."

Papillary muscles

The visceral pericardium is the same as the

Pericardium

Blood leaves the right ventricle by passing through the

Pulmonary valve

The duration of the ventricular action potential is approximately equal to the __________ interval in the electrocardiogram.

Q-T interval

Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing.

QRS complex

Into which chamber of the heart will blood flow next after the vessel indicated by the red arrow?

Right atrium (The small cardiac vein empties into the coronary sinus, which drains into the right atrium)

The arrow indicates the pericardial cavity. What term best describes the membrane on both sides of the cavity?

Serous pericardium (The serous pericardium includes both the visceral and parietal layers and completely lines the pericardial cavity)

Analysis of the electrocardiogram can reveal all of the following except the

Stroke volume

As a result of the long refractory period in the cardiac action potential cardiac muscle cannot exhibit

Tetany

Blood flowing into the heart from the venae cavae flows next through the ________ valve.

Tricuspid

The foramen ovale in the fetal heart is located in the

interatrial septum

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

left atrium

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

left atrium

Blood is supplied to the left atrium by the

left coronary artery

The circumflex branch and the anterior interventricular artery are branches of the

left coronary artery

The right pulmonary veins carry ________ blood to the ________ .

oxygenated; left atrium

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. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation?

5, 1, 3, 7, 8, 2, 4, 6

The papillary muscles function to __________.

prevent the AV valves from reversing into the atria

Contractions of the papillary muscles

prevent the atrioventricular valves from reversing into the atria

Which of the following are involved in the pulmonary circuit?

right ventricle, pulmonary trunk, left atrium

The __________ valve prevents backward flow of blood into the left ventricle.

Aortic

The right atrium receives blood from the

systemic circuit

Blood is supplied to the myocardium by

the coronary arteries

In cardiac muscle

the fast depolarization phase of the action potential is the result of, increased membrane permeability to sodium ions.

Intercalated discs serve to transfer ________ from cell to cell.

the force of contraction, action potentials, electrical signals, ionic currents

Compared to the right ventricle

the left ventricle has all the following characteristics, except that it, pumps a greater volume

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

the refractory period lasts until the muscle relaxes.

The heart pumps approximately ________ liters of blood each day.

8,000

Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute.

80-100

Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them?

Cardiac muscle cells lack transverse tubules

The P wave of the electrocardiogram is closely followed by __________.

Contraction of both atria

The first blood vessels to branch from the aorta are the ________ arteries.

Coronary

Identify the structure labeled "6."

Cusp of the tricuspid valve

If there is a complete block between the SA node and the AV node how would the ECG be affected?

The rate of P waves will be faster than the rate of QRS complexes

In cardiac muscle

about 20 percent of the calcium ion required for contraction comes from outside the cell.

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

calcium channels remaining open.

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as

cardiac tamponade

The function of an atrium is to

collect blood then pump it to the ventricle

The interventricular sulci and coronary sulcus

contain arteries, contain veins, contain fat, are grooves on the surface of the heart

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

conus arteriosus

The ________ deliver(s) blood to the myocardium.

coronary arteries

The great and middle cardiac veins drain blood into the

coronary sinus

Artery is to ________ as vein is to ________.

efferent; afferent

If the pacemaker cells in the SA node become more permeable to potassium ions the

heart rate will decrease and cells will hyperpolarize