pros'tate

A gland surrounding the first portion of the male urethra. It is made up of a fibrous capsule lined with a layer of unstriped muscular fibers which also divide the organ into a number of compartments containing small vesicles whose ducts empty into the excretory ducts. It is about \Y^ in. wide, 1%. in. long, and 1. in. deep, and is pierced by the urethra and nearer the anterior than the posterior surface by the common seminal ducts. It resembles a flattened cone with its base resting on the bladder and its apex directed upward, with the posterior surface on the rectum and the anterior just below the symphysis pubis. It is divided into three lobes — two lateral which unite in front of the urethra and are separated behind by a notch in its base, and a middle which lies between the lateral against the neck of the bladder. [Gr., prostates, from pro, before, + istana i, to set.]