A, superior vena cava; B, right auricle; C, right ventricle; D, left ventricle; E, left auricle; F, pulmonary vein; H, pulmonary artery; K, aorta; L, right subclavian artery; M, right common carotid artery; N, left common carotid artery.

A, superior vena cava; B, right auricle; C, right ventricle; D, left ventricle; E, left auricle; F, pulmonary vein; H, pulmonary artery; K, aorta; L, right subclavian artery; M, right common carotid artery; N, left common carotid artery.

From the right ventricle a large vessel called the pulmonary artery passes to the lungs, and from the left ventricle a large vessel called the aorta arches out to the general circulation of the body.

From the right ventricle a large vessel called the pulmonary artery passes to the lungs, and from the left ventricle a large vessel called the aorta arches out to the general circulation of the body.

These valves, when shut, prevent any backward flow of the blood on the right side between the pulmonary artery and the right ventricle, and on the left side between the aorta and the left ventricle.

These valves, when shut, prevent any backward flow of the blood on the right side between the pulmonary artery and the right ventricle, and on the left side between the aorta and the left ventricle.

These two veins bring venous blood from all parts of the body, and pour it into the right auricle, whence it passes into the right ventricle.

From the right ventricle arises one large vessel, the pulmonary artery, which soon divides into two branches of nearly equal size, one for the right lung, the other for the left.

Thus the blood is pumped from the right ventricle into the pulmonary artery and distributed throughout the two lungs (Figs. 86 and 88).

Thus the pulmonary artery carries venous blood from the right ventricle to the lungs, as the pulmonary veins carry arterial blood from the lungs to the left auricle.

From the left ventricle springs the largest arterial trunk in the body, over one-half of an inch in diameter, called the aorta.

that the main object of pumping the blood into the lungs is to have it purified from certain waste matters which it has taken up in its course through the body, before it is again sent on its journey from the left ventricle. 187.

After the aorta leaves the left ventricle it rises towards the neck, but soon turns downwards, making a curve known as the arch of the aorta.

The passage leading to the right ventricle lies open, and through it the blood pours till the ventricle is full.

The passage leading to the right ventricle lies open, and through it the blood pours till the ventricle is full.

The four pulmonary veins bring back bright, scarlet blood, and pour it into the left auricle of the heart, whence it passes through the mitral valve into the left ventricle.

As soon as the left ventricle is full, it contracts.

[Illustration: Fig. 75.Diagram illustrating the Circulation. 1, right auricle; 2, left auricle; 3, right ventricle; 4, left ventricle; 5, vena cava superior; 6, vena cava inferior; 7, pulmonary arteries; 8, lungs; 9, pulmonary veins; 10, aorta; 11, alimentary canal; 12, liver; 13, hepatic artery; 14, portal vein; 15, hepatic vein.

[Illustration: Fig. 75.Diagram illustrating the Circulation. 1, right auricle; 2, left auricle; 3, right ventricle; 4, left ventricle; 5, vena cava superior; 6, vena cava inferior; 7, pulmonary arteries; 8, lungs; 9, pulmonary veins; 10, aorta; 11, alimentary canal; 12, liver; 13, hepatic artery; 14, portal vein; 15, hepatic vein.

The longest route a portion of blood may take from the moment it leaves the left ventricle to the moment it returns to it, is through the portal circulation.

A, superficial fibers common to both ventricles; B, fibers of the left ventricle; C, deep fibers passing upwards toward the base of the heart; D, fibers penetrating the left ventricle ]

A, superficial fibers common to both ventricles; B, fibers of the left ventricle; C, deep fibers passing upwards toward the base of the heart; D, fibers penetrating the left ventricle ]

A, left ventricle; B, right ventricle; C, left auricle; D, right auricle; E, superior vena cava; F, pulmonary artery; G, aorta; H, arch of the aorta; K, innominate artery; L, right common carotid artery; M, right subclavian artery; N, thyroid cartilage forming upper portion of the larynx; O, trachea.

The ventricle or stomach, which is seated in the midst of that part of the belly beneath the midriff, the kitchen, as it were, of the first concoction, and which turns our meat into chylus.

Diocles supposed the ground of this kind of melancholy to proceed from the inflammation of the pylorus, which is the nether mouth of the ventricle.