CHAPTER IX. 
URINARY SYSTEM. 
THIS system consists of the kidneys, ureters, bladder 
and urethra. The action of these organs is to deal 
with the urine or what is commonly called the water 
of the animal, which is a watery fluid secreted by 
the kidneys. It varies in color, according to the condition of 
the animal's blood. 
1. The Kidneys are two in number — one on the right 
side and one on the left side, and are situated just below 
the small of the back — the right one being the furthest ahead. 
In shape, they are long and narrow, and resemble the liver 
in color. In cutting one of the kidneys open, it is found to 
be full of glands and tubes, which secrete the urine from the 
blood while it is passing through the kidneys. These tubes 
pass to the center of the kidneys, where they empty the urine 
into what is called the pelvis. The glands are largely sup- 
plied with blood vessels and nerves. The use of the kidneys 
are to secrete the urine from the blood, which contains a 
large amount of what is known as ureaic acid, and if not 
taken out of the blood by these glands, acts as poison to the 
system. 
2. The Ureters are the tubes which carry the urine down 
from the pelvis of the kidney to the bladder. They are two 
in number — one situated on the right side of the pelvic or hip 
cavity and the other on the left side close to the walls — and 
they enter one on each side at the upper part of the bladder. 
They are only about the size of an ordinary straw. ^ 
3. The Bladder is situated in the pelvic or hip cavity. 
When it is full it sometimes stretches out into the abdominal 
or belly cavity. It consists of a body and neck. The body 
is the large part, and is placed in front ; the neck being at the 
back part of the bladder. This is where the urine or water 
passes out of the bladder. The bladder is made up of three 
coats, somewhat similar to that of the bowels. The serous 
coat is a continuation of the serous coat found in the belly 
