Quiz 8 Heart

Place the steps of the conducting system in order from start to finish.

1 Stimulus spreads across the atrial surfaces and reaches the AV node. 2 SA node activity and atrial activation begin. 3 The impulse is distributed by the Purkinje fibers and relayed throughout the ventricular myocardium. Atrial contraction is completed, and ventricular contraction begins. 4 The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibers and, via the moderator band, to the papillary muscles of the right ventricle 5 There is a 100-millisecond delay at the AV node. Atrial contraction begins.

bicuspid valve

A valve in the heart that guards the opening between the left atrium and the left ventricle that prevents the blood in the ventricle from returning to the atrium.

regarding the sinoatrial (SA) and atrioventricular (AV) nodes

Any factor that changes either the resting potential or the rate of spontaneous depolarization at the SA node will alter the heart rate.

Sac-like dilations of the base of the ascending aorta occurring adjacent to each cusp are called

Aortic sinuses they prevent the individual cusps from sticking to the wall of the aorta when the semilunar valve opens

Which of the following occurs during ventricular systole?

Atrial diastole occurs. The atrioventricular valves close. Ventricular pressure exceeds arterial pressure. The semilunar valves open.

step 5 cardiac cycle

Atrial systole begins

Step One cardiac cycle

Atrial systole ends; atrial diastole begins

Place the steps in the cardiac cycle in order from start to finish.

Atrial systole ends; atrial diastole begins Ventricular diastole—early Ventricular systole—first phase Ventricular systole—second phase Atrial systole begins Ventricular diastole—late

Which cranial nerve innervates the heart for parasympathetic control?

CN X

Characteristics of cardiac muscle tissue include

Cardiac muscle has specialized cell junctions called intercalated discs. Cardiac muscle cells have relatively short T tubules that do not form triads with the sarcoplasmic reticulum. Cardiac muscle cells contract without instructions from the nervous system.

pulmonary veins

Deliver oxygen rich blood from the lungs to the left atrium

the signal for contraction passes from the sinoatrial node to the atrioventricular node via which of the following?

Internodal pathways

Why does every living cell rely on surrounding interstitial fluid for survival?

It is a place to dispose waste products. It is a source of O2. It is a source of nutrients.

Two papillary muscles

Left ventricle

step two of the conducting system

SA node activity and atrial activation begin.

step one of the conducting system

Stimulus spreads across the atrial surfaces and reaches the AV node.

Question 11:Why would a midsagittal section of the thoracic cavity NOT cut the heart in half?

The heart lies to the left of the midline of the thoracic cavity. The heart is rotated toward the left side. The heart sits at an angle to the longitudinal axis of the body.

step three conducting system

The impulse is distributed by the Purkinje fibers and relayed throughout the ventricular myocardium. Atrial contraction is completed, and ventricular contraction begins

step four conduction system

The impulse travels along the interventricular septum within the AV bundle and the bundle branches to the Purkinje fibers and, via the moderator band, to the papillary muscles of the right ventricle

aortic valve

The semilunar valve separating the aorta from the left ventricle that prevents blood from flowing back into the left ventricle.

most accurately describe the left ventricle?

There are two large papillary muscles, rather than three, in the left ventricle.

step five conducting system

There is a 100-millisecond delay at the AV node. Atrial contraction begins.

step two cardiac cycle

Ventricular diastole—early

step 6 cardiac cycle

Ventricular diastole—late

step 3 of cardiac cycle

Ventricular systole—first phase

step 4 cardiac cycle

Ventricular systole—second phase

epicardium is

a serous membrane consisting of a mesothelium covering a supporting layer of areolar connective tissue

auricle is

an expandable extension of an atrium

fibrous skeleton is

an extensive connective tissue network consisting of connective tissue layers that are continuous with dense bands of fibroelastic tissue that encircles the bases of the great vessels and the valves of the heart

fibrous pericardium is

an outer layer of dense irregular connective tissue containing abundant collagen fibers

Which branch(es) of the left coronary artery (LCA) is/are continuous with small branches of the posterior interventricular branch of the right coronary artery (RCA), thereby forming anastomoses?

anterior interventricular branch

What term is used to describe the division between the left and right ventricles indicating a linear depression on the anterior surface of the heart?

anterior interventricular sulcus

Which valves of the heart are located on the left side of the heart?

aortic valve and mitral valve

Which of the following layers of the heart wall is relatively thin and contains layers that form figure-eights as they pass from atrium to atrium?

atrial myocardium

In the systemic circuit,

blood pressure is the highest where the left and right coronary arteries originate at the base of the ascending aorta to ensure a continuous flow of blood to meet the demands of active cardiac muscle tissue

Of the different types of blood vessel, which types are considered exchange vessels?

capillaries

Which of the following structures are known as "exchange vessels" because of the exchange of nutrients, dissolved gases, and waste products that occurs through their walls?

capillaries

pulmonary trunk

carries blood from right ventricle to pulmonary arteries

the myocardium

consists of multiple, interlocking layers of cardiac muscle tissue. is the distinct middle layer of the heart wall. contains layers of cardiac muscle tissue that form figure-eights as they pass from atrium to atrium. is associated with connective tissues, blood vessels, and nerves.

conus arteriosus

contains valves to prevent blood from flowing back into the Right ventricle

The superior end of the right ventricle tapers to a smooth-walled, cone-shaped pouch called the _______________, which ends at the _______________.

conus arteriosus; pulmonary valve

Which sulcus of the heart marks the border between the atria and ventricles?

coronary sulcus

circumflex branch of LCA

curves to the left within the coronary sulcus, partially supplying the anterior two-thirds of the interventricular septum.

Blood flows from the ascending aorta through the aortic arch into which of the following vessels?

descending aorta

middle cardiac vein

drains the area served by the circumflex artery.

posterior vein of the left ventricle

drains the area served by the circumflex artery.

What type of tissue composes the valves within the heart?

endocardium

coronary sinus

enlarged vessel on the posterior aspect of the heart that empties blood into the right atrium

Which vessel(s) collect(s) blood from smaller veins draining the myocardial capillaries and deliver(s) this blood to the coronary sinus?

great cardiac vein and middle cardiac vein

Which border of the heart extends to the apex of the heart?

inferior border

anastomoses

interconnections between arteries that ensure a constant blood supply

The pulmonary trunk is attached to the aortic arch by the

ligamentum arteriosum a fibrous band that is the remnant of an important fetal blood vessel.

Which cardiac vein(s) drain(s) the area supplied by the posterior interventricular artery?

middle cardiac vein

moderator band

muscular band of heart tissue that carries a portion of the right bundle branch Right ventricle

The semilunar valves do NOT

need chordae tendineae because the relative positions of the cusps are stable, and the three symmetrical cusps support one another like the legs of a tripod.

The performance of the heart is closely monitored by what system of the body?

nervous system

Pertaining to the heart, what substance acts as a lubricant by reducing friction between opposing surfaces?

pericardial fluid

small cardiac vein

receives blood from the posterior surfaces of the right atrium and ventricle.

fossa ovalis

remnant of foramen ovale of fetal heart right atrium

The major branches of the right coronary artery include which of the following?

right marginal branch atrial branches posterior interventricular branch

A large percentage of the sternocostal surface of the heart is composed of the

right ventricle

Which chamber of the heart contracts and sends blood into the pulmonary trunk?

right ventricle

The extensive connective tissue network of the heart is the fibrous skeleton that includes

stabilizing the position of the muscle cells and valves in the heart distributing the forces of contraction providing elasticity that helps return the heart to its original shape after each contraction

posterior interventricular branch of RCA

supplies blood to the interventricular septum and adjacent portions of the ventricles.

The autonomic centers for cardiac control are found in which area?

the cardiac centers of the medulla oblongata

Physical isolation of atrial muscle cells from ventricular muscle cells is a function of which of the following?

the fibrous skeleton

The contractile stimulus from the sinoatrial node is

transmitted to cardiac muscle cells of only both atria because the fibrous skeleton electrically isolates the atrial myocardium from the ventricular myocardium.

Which of the following valves is/are found between the right atrium and the right ventricle?

tricuspid valve

How many papillary muscles are normally found in the left ventricle?

two

pulmonary valve

valve positioned between the right ventricle and the pulmonary artery

Which type of blood vessel transports blood to the heart?

vein

Question 3:Which of the following consists of loose connective tissue that is bound to the cardiac muscle tissue of the heart?

visceral pericardium

Which describes the serous membrane portion that is in direct contact with the heart?

visceral pericardium

Which of the following is the name of a serous membrane lining the pericardial cavity?

visceral pericardium