The Urogenital System


As the female reproductive system develops, the two mullerian ducts fuse together at the lower end to form the uterus. Upper portions of the two ducts will form the oviducts. These remain separate and descend laterally following the lateral descent of the ovaries. The vagina develops from the sinovaginal bulb, a thickening which develops on the wall of the urogenital sinus adjacent to its point of contact with the lower ends of the mullerian ducts. The lumen of the vagina and lower end of the uterus open after the lengthening of the sinovaginal bulb to complete the reproductive passages.



The opening to the oviduct, or osteum, forms a funnel shape surrounded by fimbriae. Fimbriae are finger-like extensions that form a crude fringe around the funnel of the osteum. This portion of the oviduct, which hangs over the the top of the ovary with its opening facing downward over the lateral end of the ovary, is called the infundibular portion of the oviduct. The ampullar portion of the oviduct is a broadened lateral portion of the tube which leads from the infundibular portion to the narrowed isthmus portion. The isthmus of the oviduct narrows as it passes into the uterine wall and extends to the uterine cavity. The uterus has a broader, larger, upper segment and a constricted neck, or cervix, at the lower end. The domed top of the uterus is called the fundus. The larger central area is called the body of the uterus. The wall of the uterus has three layers, the endometrium, myometrium, and perimetrium. The endometrium consists of internal epithelial tissues, glands, connective tissues, and blood vessels. The myometrium is a thick layer of smooth muscle. The perimetrium is the outer layer of connective tissues covered by the peritoneal epithelial lining. The lumen of the uterus is narrowed as it passes through the cervix. The rounded lower end of the cervix surrounding the opening to the uterus, extends slightly into the upper end of the vagina.















Introduction to Urogenital Development

The Human Urinary System

Human Male Reproductive System

Human Female Reproductive System

Developmenal Changes of the Human Cloaca and Lower Urogenital Structures

Development of the Human Genitals

Compartive Anatomy of Urinary and Reproductive Passages

Things To Know List