This section of the book is from "The Complete Herbalist" by Dr. O. Phelps Brown. Also available from Amazon: The Complete Herbalist: The People Their Own Physicians By The Use Of Nature's Remedies.
The bladder is a musculo-membranous sac for the reception of urine. It is situated in the cavity of the pelvis, behind the pubic bones, and in front of the rectum in the male, but in the female the uterus and vagina are between the rectum and bladder. In shape the bladder is oval, the larger end being downwards; in women it is more spheroidal; in children it is pear-shaped. It is divided into a superior and inferior fundus, a body, and neck.
Its dimensions vary with health and disease. Ordinarily it will hold about a pint. At the neck of the bladder is a circular muscle, called the sphincter, which, in a state of contraction, retains the urine in the bladder until the necessity to voiding it arises. The urethra is described under anatomy of the sexual organs.