Fig. 26—The abdominal aorta and its branches. (Gray)
The Kidneys.
—The kidneys are large glands, two in number and are situated from five to six inches apart or about three inches on either side of the median line in the right and left lumbar regions.
The upper extremity of the kidneys lies on the level of the twelfth dorsal vertebra and the lower extremity on the level of the third lumbar vertebra. Each kidney is four and one-half inches in length, two to two and one-half inches in breadth, a little more than one inch in thickness.
The weight of the kidney in the adult male is from four and one-half to six ounces each. In the adult female the weight would be from four to five and one-half ounces.
Their function is to separate from the blood certain waste products and an excess of water, the combination of which we know as urine. The principal products excreted by the kidneys from the blood along with water are ammonia and urea. The blood is taken to the kidneys by the renal arteries and the renal veins carry it back to the blood circulation.
The urine is then taken from the kidneys by the ureters and conveyed to the urinary bladder.
The Ureters.
—The ureters are cylindrical tubes about sixteen inches in length and of diameter of a goose-quill.