All red-blooded animals have spleens: their removal from the body does not cause appreciable permanent disturbance. The spleen has few functions that can be determined accurately, and it is quite evident that other organs with which it is associated in function readily assume its work. The changes in the spleen found in general necropsy service are seldom characteristic of the disease which caused death. The spleen has no known internal secretion and its nerve connection consists of unimportant fibers from the sympathetic and parasympathetic systems. It contains a small amount of nonstriated muscle, which, as in other portions of the body, has the power to originate contraction, and, like the heart, the uterus and the intestine, it originates certain rhythmic contractions, noticeably during the digestive period.
The spleen, according to Gross,1 has characteristics referable to age. In early life, the germinal foci in the malpighian corpuscles and endothelial buds
MAYO WJ. RELATION OF CHRONIC FIBROSIS AND THROMBOPHLEBITIS OF THE SPLEEN TO CONDITIONS OF THE BLOOD AND OF THE LIVER. Arch Surg. 1921;2(2):185-195. doi:10.1001/archsurg.1921.01110050003001