Ch 2: The heart

What is the primary function of intercalated discs in cardiac muscle cells?

To connect muscle cells and facilitate the synchronized contraction of the heart 

Which of the following correctly describes excitation-contraction coupling?

ATP binds to myosin heads, causing them to detach from actin filaments after the power stroke, allowing muscle relaxation.

In the conduction system of the heart, which of the following is the correct order of impulse transmission?

Sinoatrial Node → Atrioventricular Node → Bundle of His → Purkinje Fibers  

Muscular ridges inside the atria of the heart involved in atrial contraction.

Pectinate muscles

Irregular muscular ridges on the inner walls of the ventricles.

Trabeculae carneae

A large artery that carries deoxygenated blood from the right ventricle to the lungs.

Pulmonary artery

The upper right chamber of the heart, receiving deoxygenated blood through the superior and inferior vena cavae.

Right atrium

A small, ear-like extension of the atria to increase atrial volume.

Auricle

Valve located between the left atrium and left ventricle to stop the backflow of blood into the atria during ventricular contraction

Left AV valve (bicuspid)

A large vein carrying deoxygenated blood from the head, neck, arms, and chest into the right atrium of the heart.

Superior vena cava

Tendinous, collagenic cords attaching the leaflets of the atrioventricular valves to the papillary muscles.

Chordae tendineae

A valve located between the right ventricle and pulmonary artery, preventing backflow of blood into the ventricle.

Pulmonary valve

The lower right chamber of the heart, responsible for pumping deoxygenated blood to the lungs via the pulmonary artery.

Right ventricle

Vessels that carry oxygenated blood from the lungs to the left atrium of the heart.

Pulmonary veins

A valve located between the right atrium and right ventricle, preventing backflow of blood into the atrium.

Right AV valve (tricuspid)

The passageway in the fetal heart between the right and left atrium that allows blood to bypass the fetal lungs.

Foramen ovale

The largest vein in the body, transporting deoxygenated blood from the lower body into the right atrium.

Inferior vena cava

A depression in the right atrium of the heart, the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development.

Fossa Ovalis

Cone-shaped muscles tethering the chordae tendineae of the atrioventricular valves.

Papillary muscles

The part of the circulatory system that carries deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart

Pulmonary circulation

The upper left chamber of the heart, receiving oxygenated blood from the lungs through the pulmonary veins.

Left atrium

The lower left chamber of the heart, responsible for pumping oxygenated blood through the aorta to the systemic circulation.

Left ventricle

Blood from the _____ flows into the left atrium.

Pulmonary veins

The right atrium receives blood from the _______.

Superior vena cava

The tricuspid valve is located between the ________.

Right atrium and right ventricle

There is a semilunar valve between the ________.

Left ventricle and the aorta

The left coronary artery branches into the left anterior descending artery and the _______.

Circumflex

The right coronary branches into the _______.

Posterior interventricular artery

Right marginal artery

The coronary sinus delivers blood into the ______

Right atrium

The anterior cardiac veins empty directly into the right atrium, bypassing the coronary sinus?

True

Which vessel collects blood to bring it back from the anterior portion of the heart and delivers it to the coronary sinus?

Great cardiac vein

When the atria are contracting, the AV valves are open and the semilunar valves are closed?

True

When the ventricles are contracting, the semilunar valves are closed and the AV valves are open?

False

The serous membrane surrounding the heart is called the ________.

Pericardium

The function of the chordae tendineae is to:

Prevent the inversion of the AV valves during ventricular contraction

Once carbon dioxide and oxygen have been exchanged in the pulmonary capillaries, the oxygenated blood travels back to the heart in the ________.

Pulmonary veins to the left atrium

The pericardial cavity contains?

Pericardial fluid

A heart attack, or myocardial infarction, is when there is tissue death in the heart because of lack of oxygen. Which layer would be damaged?

Myocardium

Damage to the conduction system of the heart that prevents the impulse from traveling in through the AV node is called ________.

Heart block

The foramen ovale is located:

In the interatrial septum

Deoxygenated blood is returned to the heart via the _______

Coronary sinus

Anterior cardiac veins

Inferior vena cava

Superior vena cava

Which ventricle has the thickest myocardium?

Left

What is the function of the adipose tissue found on the heart? Where is it located?

The adipose tissue is found on the surface of the heart. Adipose tissue provides cushioning and protection to the heart. It also serves as an energy reserve.

How can the right and left ventricles be distinguished from one another?

The myocardium of the left is thicker. The inter ventricular septum also separates the right from the left ventricle.

A blunt probe is placed through one of the great vessels and enters the right ventricle. Which great vessel was the probe placed in?

The pulmonary trunk

The bicuspid valve separates which two chambers?

The left atrium from the left ventricle

Name the structure in the heart responsible for initiating the heartbeat by automatically depolarizing.

SA node

An EKG measures:

Electrical potentials over time

Name the structure in the heart responsible for initiating the heartbeat by automatically depolarizing.

SA node

Which chamber of the heart has the thickest wall and why?

Left ventricle because it pumps oxygenated blood to all parts of the body.

What is the function of the mitral valve in the heart?

It prevents backflow of blood from the left ventricle to the left atrium

The pulmonary veins bring the blood to which chamber?

Left atrium

The heart is placed in a space between the lungs, superior to the diaphragm. This area is referred to as the _______.

Mediastinum

On an electrocardiogram (EKG), which wave aligns with ventricular depolarization?

R wave

In an EKG, the interval that represents the time taken for the electrical impulse to travel from the sinoatrial (SA) node through the atria, antrioventricular (AV) node, and down to the ventricles is known as the ________.

PR interval

Which statement accurately describes the difference between the semilunar valves and the atrioventricular (AV) valves in the heart?

Semilunar valves are found between the ventricles and the major arteries, while AV valves are located between the atria and ventricles.

AV valves close when pressure is greater from below, whereas the semilunar valves close when pressure is greater from above.

Pectinate muscles are located in the:

Atria