THE UROGENITAL SYSTEM 



425 



grow down into the underlying connective tissue. This mucous hning, 

 the endometrium, is partly lost during menstruation with some extravasa- 

 tion of blood. The thick muscular wall of the uterus consists of inter- 

 woven masses of^ smooth muscle fibers. Uterine and ovarian vessels 

 provide the blood supply. The nerve supply is sympathetic. 



The Vagina. The vagina provides the outlet of the reproductive 

 apparatus. It is a highly distensible muscular canal between two and 

 three inches in length, extending from the lower end of the uterus, the 

 OS uteri, to the vestibule. Previous to sexual congress its external opening 

 is more or less completely occluded by a membranous hymen. The vagina 



^-OVARIAN LIGAMENT 



PUBIC- 

 SYMPHYSIS 



'UROGENITAL 

 DIAPHRAGM. 



Fig. 350. — The urogenital system — female. (Sobotta.) 



is Hned with squamous stratified epithehum free from glands. Its 

 muscles are divided into circular and longitudinal layers of smooth fibers. 

 Near its orifice the bulbo-cavernosus muscle acts as a sphincter. 



External Genitals. The external genital organs in the female form 

 a median longitudinal groove extending from the mens pubis in front 

 nearly to the anus behind. This groove is bordered by two fleshy folds, 

 the labia majora, which contain considerable fatty tissue, and which are 

 somewhat beset with hairs both on their inner and outer surfaces. Usu- 

 ally, the median edges of the labia majora are in contact with one another, 

 thus conceaHng the remaining parts of the external genitals. Sebaceous 

 and sweat glands are numerous on the median surfaces. (Fig. 350) 



Between and more or less concealed by the labia majora is a second 

 pair of integumentary folds, the labia minora, which are devoid of fat 



