The Circulatory System II: The Heart

What disease is the leading cause of death in the United States?

Heart disease

Which circuit carries blood to the lungs for gas exchange and returns it to the heart?

Pulmonary

_____ and _____ _____ _____ regulate flood flow between the ventricles and great arteries. There are no tendinous cords, but rather pocket-like cups that flatten against the arterial walls when blood surges through.

Pulmonary and aortic semilunar valves

The right side of the heart is involved in the _____ circuit.

Pulmonary- it receives oxgen-poor blood from veins and sends it to the lungs via the pulmonary trunk. Pulmonary veins return the freshly oxygenated blood to the left side of the heart.

Which circuit supplies blood to all the tissues of the body?

Systemic

The right and left ventricles pump blood to _______.

arteries

The _____ have thin, flaccid walls because they only have to pump blood to the ventricles.

atria

The thin-walled _____ receive blood returning to the heart from the great veins.

atria

What is the most common condition that can lead to myocardial infarction?

coronary atherosclerosis

A system of blood vessels is called the _____.

coronary circulation

What encircles the heart near the base and separates the atria from the ventricles?

coronary sulcus

Coronary blood flow is greatest in ____, when the ventricles are relaxed. It is reduced in ____, when contraction of the ventricles compresses the coronary vessels.

diastole; systole

A thin inner wall, the _______, lines the interior of the heart and is continuous with the endothelium of blood vessels.

endocardium

The thin outer layer of the heart wall is the ______ (visceral pericardium) that consists of simple squamous epithelium on top of the areolar tissue.

epicardium

The cardiovascular system consists of the ___, ____, and ____.

heart, blood, and blood vessels

The chambers are internally separated by an ______ septum between the atria and the ______ septum between the ventricles.

interatrial; interventricular

Heart is slightly tilted toward the _____.

left

The two upper chambers of the heart are the ____ and ___ ___, and serve to receive blood from the _____ ____ and ____ ____, respectively.

left and right atria; venae cavae and pulmonary veins

The thick walls of the ____ ____ are commensurate with its task of pumping blood to all the tissues of the body.

left ventricular

Obstruction of a coronary artery deprives the downstream myocardium of a blood supply and may cause _______.

myocardial infarction (heart attack)

The middle layer of the heart, the _______, comprises the bulk of the wall and is made up mostly cardiac myocytes.

myocardium

The _______ is a double-walled sac that encloses the heart.

pericardium

Two main divisions of the cardiovascular system are?

pulmonary circuit and systemic circuit

The two lower chambers are the ____ and ____ _____, which eject blood into the ____ ___ and ___, respectively.

right and left ventricles; pulmonary trunk and aorta

The _____ _____ occupies most of the anterior aspect of the heart while the _________ _______ makes up the apex and the inferoposterior aspect.

right ventricle; left ventricle

The _____ _____ wall is moderately thick since it has to pump blood to the lungs.

right ventricular

The left side of the heart is involved in the _____ circuit.

systemic- pumps the blood to the huge aorta that arches off the top of the heart and immediately begins giving off arteries that supply tissues of the body. The blood returns to the heart via veins that finally converge on the superior vena cava and inferior vena cava that enter the right side of the heart.

The heart is located in the ______ cavity in the ________, between the lungs and deep to the sternum.

thoracic; mediastinum

What are the four chambers of the heart?

two superior atria and two inferior ventricles

When veins empty into coronary sinus, it is called?

venous drainage