Agriculture Reference
In-Depth Information
Figure 6.30
The liver and spleen: A. Visceral aspect of the liver, in situ; B. Parietal aspect of the liver;
C. Visceral aspect of the spleen.
mids, whose tips oriented toward the renal sinus open on
a common renal crest. The latter empties the urine into the
renal pelvis, which is the mucosal coat lining the renal
sinus. The renal pelvis continues as the ureter. Both exter-
nal aspect and internal conformation are shown in Figure
6.31. As to function, the kidneys process the blood by a
complex mechanism of fi ltration, reabsorption, and secre-
tion, and expel the result of this activity, the urine, through
the urethra.
organ with lumen, the urinary bladder has three coats:
peritoneum on the outside, a muscular coat in the middle,
and a mucosal coat inside. Pear-shaped, it lies on the fl oor
of the pelvic cavity and slips more or less into the abdomi-
nal cavity when too full of urine. It continues with the
urethra through a narrow neck. The ureters open through
the dorsal wall of the urinary bladder close to the neck.
They perforate obliquely the muscular coat of the urinary
bladder, then travel for a short distance between the mus-
cular and the mucosal coats before opening close to each
other.
The female urethra is very short and opens on the fl oor
of the vagina, between the vagina and vestibulum. The
male urethra will be described with the reproductive
organs.
The Ureter
The ureter is a tubular organ, with a peripheral fi brous coat
(the continuation of the renal capsule), a muscular coat,
and a mucosal membrane (the continuation of the renal
pelvis). The muscular coat pushes the urine in peristaltic
waves into the urinary bladder. The ureters run on the roof
of the abdominal cavity and enter the pelvic cavity to reach
the neck of the urinary bladder.
THE REPRODUCTIVE SYSTEM
The Male Reproductive System
This consists of three categories of organs: the essential
organs (the testicles) with the investing layers (the testicu-
lar tunics), the passages leading the sperm through the
The Urinary Bladder
The urinary bladder has the function of a temporary recep-
tacle of urine, which is emptied through the urethra. As an
