The Urinogenital System
Female Reproductive System
In the female, with the exception of the clitoris and the labia, the parts of the reproductive system are inside the body. Like the male, the pelvic girdle protects the organs, but it is larger in a female so that a baby can be expelled.
Fig. 1 Female Reproductive System (cross section)
The vagina is a muscular passage leading from the cervix to the vulva and connects the internal organs with those on the outside of the body.
The vagina serves as a passage for menstrual blood, is the site of penetration during intercourse and also forms part of the birthing canal.
The vulva (collective name for the external organs) include:
Fig. 2 Uterus
The uterus is the centre of female reproduction and is also known as the womb. Here, fetrilised ova grow into babies.
The top of the uterus opens into the fallopian tubes and the bottom (cervix) opens into the vagina, forming the birth canal.
The uterus is a muscular, hollow organ that sits at right angles to the vagina and is the size and shape of an upside down pear (7.5cm long and 5 cm wide). During pregnancy it expands to accommodate the foetus. The lining of the uterus is made up of tissues that respond to hormonal secretions; each month these layers thicken in anticipation of acting as a nourishing bed for a fertilised ovum.
The ovaries are glands not much bigger than the size of an almond, and are positioned either side of the uterus. The ovaries secret hormones responsible for female characteristics, as well as storing female sex cells. At birth, all the eggs necessary for a lifetime of reproduction are present in the ovaries as immature follicles. When FSH signals the ovary to develop a follical, it eventually ruptures and releases an ovum.
The breasts are accesory organs to the reproductive system. They develop during pregnancy ready for their function of secreting milk.
Situated at teh front of the chest, each breast is circular and convex, with a central raised nipple. They consist of adipose tissue supported by fascia. The tissue forms lobes, subdivided into lobules that open into several ducts. These ducts open on the surface of the nipple. Hormones cause the breasts to grow during puberty, and during pregnancy activate the secretion of milk.
Fig. 3 Breast