A&P Chapter 17

tachycardia

Archie has a resting heart rate of 125 beats per minute. Classify his cardiac dysrhythmia.

cardiac pacemaker cells.

Autorhythmicity is the responsibility of:

vena cavae

Blood from the systemic circuit returns to the heart via the __________.

tricuspid valve and into the right ventricle.

Blood in the right atrium should travel next past the:

left atrium

Blood returning from the lungs enters the __________.

pulmonary trunk

Blood that leaves the right ventricle enters the __________.

the veins

Both the left and right atria receive blood from:

closes the AV valves

During the isovolumetric contraction phase, the pressure in the ventricles rises rapidly as the ventricles begin to contract. This high pressure ____________________________

120 ml.

End-diastolic volume for each ventricle during rest is normally about:

coronary sinus

Generally, coronary veins empty into a vessel known as the:

QRS wave

On an electrocardiogram (ECG), atrial repolarization is obscured by the:

3,6,1,4,2,5

Place the following parts of the cardiac conduction system in the order in which they transmit the action potential. 1) atrioventricular (AV) bundle 2) Purkinje fibers 3) sinoatrial (SA) node 4) right and left bundle branches 5) contractile cells of cardiac muscle tissue 6) atrioventricular (AV) node

Both AV valves are forced shut while both semilunar valves are forced open.

Predict the position of the valves when the ventricles contract.

70 ml per heart beat.

Stroke volume averages about:

ventricle increases

The AV valves close when __________.

ventricular repolarization

The T wave of an ECG corresponds to __________.

pressure in the left ventricle falls below aortic pressure

The aortic valve closes when __________.

inferior

The apex of the heart is __________.

left ventricle

The cardiac chamber with the thickest wall is the __________.

ventricles

The chambers that have just emptied when the second heart sound is heard are the __________.

chordae tendineae

The cusps of the atrioventricular valves attach directly to:

in the mediastinum

The heart is located _________.

mediastinum

The heart is situated in the middle of the thoracic cavity in a region known as the:

most pressure

The left ventricle has the thickest wall because it has to generate the

SA node

The main pacemaker of the heart is the __________.

sinoatrial (SA) node.

The right and left atria depolarize and contract following the arrival of the action potential from the:

aorta

The right and left coronary arteries receive blood from the:

pulmonary arteries

The right side of the heart pumps deoxygenated blood into _____.

deoxygenated blood from the systemic circuit.

The right side of the heart receives:

superior and inferior venae cavae

The two veins that drain the majority of the systemic circuit are the ____________________________

epicardium

The visceral pericardium is also known as the __________.

stroke volume

The volume of blood pumped by each ventricle in one heartbeat is known as:

SA node; parasympathetic NS

The____________ sets the heart rate at 100 beats per minute, but the ___________________ slows it down to 75 beats per minute.

The Frank-Starling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract.

What best describes the Frank-Starling law?

intercalated discs

What characteristic differentiates cardiac muscle cells from skeletal muscle cells?

prevent backflow of blood through the heart

What is the function of the valves in the heart?

papillary muscles

What muscles, present in the ventricles, anchor by tendon-like chords called chordae tendineae?

the vibrations of the ventricular and blood vessel walls when valves shut

What produces the "lub dub" heart sounds?

right atrioventricular valve (tricuspid valve)

What valve prevents the backflow of blood from the right ventricle into the right atrium?

pulmonary semilunar valve

When the right ventricle contracts, blood passes through the _________________ into the pulmonary trunk

aorta

Where should the left ventricle send blood?

left ventricle

Which chamber experiences a maximum pressure of around 118 mm Hg during contraction?

vagus nerves (CN X)

Which cranial nerves have a negative chronotropic effect on heart rate?

atrial natriuretic peptide

Which hormone decreases cardiac output by decreasing blood volume and preload?

acetylcholine

Which of the following decreases heart rate?

pulmonary vein

Which of the following does NOT return blood to the right atrium of the heart?

pulmonary vein

Which of the following vessels carries oxygenated blood?

foramen ovale

Which opening in the interatrial septum of the fetal heart connects the right and left atrium?

the right marginal artery and the right posterior interventricular artery

Which two arteries arise from the right coronary artery?

pulmonary trunk

Which vessel is guarded by a semilunar valve at its base?

aorta

Which vessel supplies the systemic circuit with oxygenated blood?

QRS wave

Which wave on the electrocardiogram (ECG) represents ventricular depolarization?