Chapter 19 The Heart

The region between the right and left pleural cavities is the

Pulmonary cavity

The heart chamber that receives oxygenated blood from the pulmonary veins.

left atrium

The heart chamber that receives blood from the superior vena cava, inferior vena cava, and coronary sinus.

Left atrium

Threadlike structures of the endocardium that prevent prolapse of the atrioventricular valves.

chordae tendineae

The valve responsible for preventing backflow of blood from the lungs into the heart.

Pulmonary semilunar valve

Contraction of these structures tightens the chordae tendineae, preventing valve prolapse.

Papillary muscles

Cells of the conducting system located between the AV node and bundle branches.

atrioventricular bundle

Large cardiac cells of the conducting system embedded in the ventricular walls between the endocardium and myocardim.

atrioventricular bundle

Parasympathetic impulses to the SA node are transmitted on this cranial nerve.

Vagus nerve

Death of heart musculature due to lack of oxygen.

myocardial infaction

The pericardial cavity lies between

the parietal pericardium and the visceral pericardium

The inner endothelial layer that line the heart is the

endocardium

Which of the following vessels does not carry oxygen-poor blood to the heart?

the pulmonary vein

The superior corner of the right atrium of the heart is located at the

costal cartilage of the third rib whrere it attaches to the sternum.

The auricles are

earlike flaps on the surface of the atria

What structures anchor the choreae tendineae?

papillary muscles

Which of the following structures is not found in the left ventricle?

the pectinate muscles

The right ventricle pumps blood into which vessel?

the pulmonary trunk

A drop of blood returning to the heart from the head region would enter theheart through which vessel?

the superior vena cava

Semilunar valves are located

between the ventricles and the great arteries

What is the effect of the parasympathetic fibers carried by the vagus nerve?

They slow the heartbeat.

Which vessel returns most of the venous blood from the heart to the right atrium?

the coronary vein

During ventricular systole, blood is

forced from the ventricles into the aorta and pulmonary trunk

Blood within the pulmonary veins returns to the

left atrium

The term for pain caused by deficient blood delivery to the heart wall is

angina pectoris

Blood is carried to capillaries in the myocardium by way of the

coronary arteries

Which of the following veins does not deliver blood directly to the right atrium?

the great cardiac veins

Oxygen-poor blood returns to the heart and enters the

right atrium

The epicardium is the same as the

visceral layer of the serous pericardium

The heart chamber with the thickest wall is the

left ventricle

the heart chamber that pumps oxygenated blood around the systematic circuit is the

left ventricle

If the beating heart makes a lub-dup sound the dup sound is caused by

vibrations that result from the semilunar valves slamming shut

Of the three layers of the heart wall, the layer that contains the cardiac muscle is the

myocardium

There is a foramen ovale in the skull and another one in the heart. The foramen ovale in the heart gives rise to the

fossa ovalis

the "heartstrings" are

chordae tendineae

The semilunar valves are closed when

the ventricles are relaxing

The atriventriclar node is located in the

inferior part of the interatrial septum.

The left ventricular wall of the heart is thicker than the right ventricular wall so that it can

pump blood with greater pressure

During left ventricular systole, blood exits the heart to enter the

aorta

The tricuspid valve is closed

when the ventricle is in systole

In the pericardial sac, the ____ lies directly deep to the fibrous pericardium.

parietal layer of the serous percardium

The cardiac centers that control heart rate are located in the

medulla oblongata of the brain stem

The correct sequence of heart wall layers from superficial to deep is epicardium, endocardium, and myocardium.

FALSE

Papillary muscles are horizontal ridges in the walls of the atrium.

FALSE

Oxygen-rich blood returning from the lungs enters the left atrium through two right and two left pulmonary veins.

TRUE

Contraction of the hearts proceeds first on the right side of the heart and second on the left.

FALSE

The electrical event that begins each heartbeat occurs at the sinoatrial node

TRUE

Contraction of the ventricles begins at the apex and proceeds superiorly.

TRUE

The right and left coronary arteries arise from the descending aorta.

FALSE