Spleen
one of the abdominal glands at the left side of the body, close to the stomach and pancreas. It is somewhat oval-shaped and concave internally, where it is divided by a fissure named the hilum. Here blood-vessels enter and leave the organ, and the nerves also enter. The upper extremity of the spleen is thick; the lower which is in contact with the colon, is more pointed. The average length of the spleen is 5 inches, its breadth 3 or 4 inches, and its thickness 1 or 1½ inches. Its weight is about seven ounces. The spleen is a meshwork of fibers or trabeculæ, supporting a soft matter named the spleen pulp.
Microscopically examined, the latter is found to consist of blood corpuscles in a state of disintegration. The spleen substance also includes certain small round bodies, attached to the sheaths of the blood-vessels of the spleen, and named Malpighian or splenic corpuscles.
During digestion the spleen increases in size, but under starvation it decreases, and the Malpighian bodies disappear.
The spleen is supplied with blood by the splenic artery; its nerves are derived from the right pneumogastric nerve, and from the left semilunar ganglia.
This organ may be excised from man and other animals without impairing the health. Most of the diseases of the spleen occur as secondary affections in connection with other diseases, such as ague and leucocythæmia. Amyloid degeneration of the spleen is frequently associated with a similar disease in the 32 SPOFFORD, HARRIET PRESCOTT liver or kidneys. The spleen is enlarged and increased in density, and it feels to the touch like wax. Splenitis or inflammation of the spleen is rare in this country, but is common in tropical malarial districts and is usually associated with ague. The symptoms are pain in the left side, in the hypochondriac region, and considerable tumefaction. The hypertrophied spleen may encroach on the stomach, and by upward pressure disturb the heart's action, or it may extend downward into the pelvic region. The diffuse inflammation may terminate by resolution, but pus may form or the spleen may become gangrenous. Tumefaction generally subsides rapidly; but more or less hypertrophy may remain.
Atrophy of the spleen is a much less frequent affection.
SPLICE. See KNOTS.
SPLÜGEN, an Alpine pass in the Grisons, Switzerland; at an altitude of 6,946 feet; connects the valley of the Farther Rhine with that of a tributary of the Adda; and has been used for crossing the Alps since the time of the Romans. The existing road, 24 miles long and 14½ feet wide, was made by the Austrian Government in 1812-1822.
It is protected against avalanches by several galleries and refuges.