Heart

When the semilunar valves are open, what is occurring?

(2) AV valves are closed (3) ventricles are in systole (5) blood enters aorta (6) blood enters pulmonary arteries

Freshly oxygenated blood is first received by the

(b) left atrium

The activity of the heart depends on intrinsic properties of cardiac muscle and on neural factors. Thus,

(a) vagus nerve stimulation of the heart reduces heart rate (b) sympathetic nerve stimulation of the heart decreases time available for ventricular filling, (c) sympathetic stimulation of the heart increases its force of contraction

In the heart, which of the following apply?

1) Action potentials are conducted from cell to cell across the myocardium via gap junctions (2) the SA node sets the pace for the heart as a whole (3) spontaneous depolarization of cardiac cells can occur in the absence of nerve stimulation

The fact that the left ventricular wall is thicker than the right reveals that it

(b) pumps blood against greater resistance

The chordae tendineae

keep the AV valves from everting during ventricular systole

The sequence of contraction of the heart chambers is

(c) both atria followed by both ventricles

List 3 factors that decrease contractility

1. Acidosis 2. Increased extracellular K 3. Calcium channel blockers

List 4 things that increase contractility

1. Increased sympathetic stimuli 2. Certain hormones 3. Ca++ 4. Some drugs

When the atria begin depolarizing, which of the following is occuring?

A) ventricular filling
B) ventricular ejection
C) atrial filling
D) atrial ejection

c.) atrial filling

Cardiac muscle depends almost entirely on aerobic respiration to make ATP.
A) True
B) False

A. TRUE

The semilunar valves are the valves that prevent the blood from flowing back into the atria when the ventricles contract.

A) True
B) False

B. FALSE

The chordae tendineae are connected to the walls of the ventricle via the papillary muscles.

A) True
B) False

A. TRUE

Which chambers of the heart are at the base of the heart?

A) atria
B) ventricles

…

Which of the following is the connective tissue layer that covers the external surface of the heart?

A) pericardium
B) myocardium
C) endocardium
D) epicardium

EPICARDIUM (D)

Which of the following is the connective tissue layer that surrounds the internal surface of each chamber of the heart?

A) pericardium
B) myocardium
C) endocardium
D) epicardium

ENDOCARDIUM

Which of the following refers to the cardiac muscle tissue?

A) pericardium
B) myocardium
C) endocardium
D) epicardium

B) myocardium

Unlike skeletal muscles, cardiac muscle has this feature:

A) larger cisternae
B) smaller T tubules
C) several nuclei
D) long, slender, unbranched cells
E) calcium ions can come from ECF

E) calcium ions can come from ECF

This chamber has to work harder than the others, so it has the thickest myocardium:

A) right ventricle
B) left ventricle
C) right atrium
D) left atrium

B) left ventricle

All of the following are cardiac stimulants except:

A) epinephrine
B) caffeine, nicotine, and chocolate
C) thyroid hormone
D) potassium and calcium ions

D) potassium and calcium ions

It is essential that both ventricles eject the same amount of blood even though the pressure in the right ventricle is much less than the pressure in the left ventricle.

A) True
B) False

a. true

When the ventricles relax blood in the aorta flows back toward the heart filling the coronary arteries.

A) True
B) False

a. true

Which of the following valves keeps blood from backing up into the left ventricle?

A) pulmonary valve
B) bicuspid valve
C) aortic valve
D) tricuspid valve

c. aortic valve

The valve that lies between the right atrium and the right ventricle is the:

A) aortic semilunar valve
B) tricuspid valve
C) mitral valve
D) bicuspid valve

B) tricuspid valve

An artery is defined as:

A) a vessel that carries blood away from the heart

Atrial pressure is at its highest when:

A) the AV valve is closed
B) the AV valves are open
C) the semilunar valves are closed
D) the valves have no influence on atrial pressure

B) the AV valves are open

describes a route that blood can take in a normal human?

C) left atrium > bicuspid valve > left ventricle > aortic semilunar valve

Closure of the AV valves occurs when:

A) the second heart sound is heard
B) ventricular pressure exceeds atrial pressure
C) atrial pressure exceeds ventricular pressure
D) ventricular pressure and atrial pressure are equal
E) blood is ejected from the ventricles

B) ventricular pressure exceeds atrial pressure

true or false?

Ventricular contraction begins at the AV valves and progresses downward toward the apex of the heart.

true

Which of the following structures allow one cardiac cell to electronically stimulate another by allowing ion flow across the intercalated disk?

A) fascia adherens
B) gap junctions
C) desmosomes
D) intercellular folds

B) gap junctions

The first three branches off the aorta are the right, left, and middle coronary arteries.

A) True
B) False

b. false

The pulmonary valve has string-like chordae tendineae and papillary muscles that prevent the valve cusps from prolapsing during right ventricular contraction.

A) True
B) False

false

Which of the following is associated with the atria?

A) trabeculae carneae
B) pectinate muscles
C) chordae tendineae
D) papillary muscles

B) pectinate muscles

The lining of the chambers and the covering of the heart are a simple squamous epithelium overlying a thin layer of loose connective tissue.

A) True
B) False

true

The anterior interventricular artery and the circumflex artery are the main branches of the right coronary artery.

A) True
B) False

false

The ____________ collects blood from all other veins draining the myocardium and returns this blood to the right atrium.

A) great cardiac vein
B) left circumflex artery
C) posterior cardiac vein
D) coronary sinus
E) middle cardiac vein

D) coronary sinus

The atria never need to contract due to passive ventricular filling.
A) True
B) False

false

The beginning of ventricular systole is when blood flowing back toward the relaxed ventricles causes the semilunar valves to close.

A) True
B) False

false

When the pressure in the ventricles becomes lower than the pressure in the atria…

A) the ventricles contract.
B) blood flows into the pulmonary trunk.
C) blood flows into the aorta.
D) the atrioventricular valves open.
E) the semilunar valves open.

AV valves open

Ventricular systole causes…

A) blood to flow into the ventricles.
B) blood to flow out of the atria.
C) the atrioventricular valves to close, and then the semilunar valves to open.
D) the semilunar valves to close, and then the atrioventricular valves to open.
E) pressure to become greater in the aorta and pulmonary trunk than in the ventricles.

C) the AV valves to close, and then the semilunar valves to open.

The ventricles begin to fill during ventricular diastole.

A) True
B) False

TRUE

Atrial contraction accounts for most of the ventricular filling.
A) True
B) False

FALSE

The atrioventricular valves open during…
A) ventricular systole.
B) ventricular diastole.
C) atrial systole.
D) atrial diastole.
E) both atrial and ventricular systole.

B) ventricular diastole.

The semilunar valves close during…

A) ventricular systole.
B) ventricular diastole.
C) atrial systole.
D) atrial diastole.
E) both atrial and ventricular systole.

B) ventricular diastole

Which of the following is not true for ventricular systole?

A) the ventricles contract.
B) the atrioventricular valves close.
C) the semilunar valves open.
D) the ventricles relax.
E) blood flows through the aorta and the pulmonary trunk.

D) the ventricles relax.

In the ventricles, the action potential travels along the interventricular septum to the apex of the heart, where it then spreads superiorly along the ventricle walls.

A) True
B) False

TRUE