As has been demonstrated, all these gases are absorbed by water, and a saturated solution possesses the properties of the gases themselves.
PHYSIOLOGY.
GENERAL VIEW OF THE CIRCULATING APPARATUS OF MAN.
The course and relative positions of the principal arteries and veins of the Systemic circulation are shown in this plate. The arteries commence from the great arterial trunk, called the aorta, and their branches are distributed to all parts of the system. The venous branches, which accompany the arteries, unite into two great veins, the superior and inferior vena cava, which convey the blood back to the heart.
a, The left ventricle of the heart. b, The right auricle. c, The superior vena cava. d, The root of the pulmonary artery. e, e, The aorta, which is seen arching backward over the heart, and passing downward into the abdomen, where it divides into its two great branches, the iliac arteries, through which the blood passes to the lower extremities. f, The inferior vena cava, which accompanies the descending aorta and its branches, and returns the blood from the lower extremities. The dotted lines represent the outlines of the kidneys.
PRINCIPAL DIVISIONS OF THE AORTA AND VENA CAVA.
It should be remembered that most of the branches which spring from the great artery and vein are double—that is, each right branch has a corresponding one at the left side—so that there are, for instance, the right and the left carotid arteries, the right and the left jugular veins, etc.
From the arch of the aorta are sent off those arteries which are distributed to the head and arms. The principal ones among these are named as follows:
g, The carotid artery, which ascends in the side of the neck, and divides into the temporal artery, h, which is distributed in the temple, and the facial artery, i, which supplies the face; and also sends a branch, called the internal carotid, to the parts within the skull.
j, The sub-clavian artery, lying beneath the clavicle or collar-bone. That part of the continuation of this artery which passes through the axilla or arm-pit is called the axillary artery, k; that which lies in the upper arm, the brachial artery, l; and in the fore-arm it divides into the radial and ulnar arteries, m, n, which are distributed to the hand and fingers in the manner indicated in the plate.