of the muscles in the wall of the oviduct combine with beating cilia to move the egg in the tube.Female mammals have a uterus in which the fetus develops during pregnancy. The uterus is situated between the urinary bladder and the rectum and is shaped like and inverted pear. The uterus is composed of a thick, muscular layer and a thin lining called the endometrium. Its lower end, called the cervix, tapers to a narrow opening into the vagina. The vagina is a passageway between the uterus and the outside of the females body. The female external genitals are collectively known as the vulva. The labia minora is a thin membrane of folded skin just outside the vaginal opening. The labia majora cover and protect the genital area. A clitoris, important in arousal, is a short shaft with a sensitive tip covered by a fold of skin.Puberty In FemalesPuberty in females begins when the hypothalamus signals the anterior lobe of the pituitary to produce and release the hormones FSH and LH. In females FSH stimulates the development of a follicle in the ovary. A follicle is a group of epithelial cells that surround an undeveloped egg cell. FSH also causes the release of the hormone estrogen from the ovary. Estrogen is the steroid hormone responsible for the secondary sex characteristics of females. These characteristics include the growth and maintenance of female sex organs; an increase in fat deposits in the buttocks, thighs, and breast; a broadening of the hips; and an increase in body hair. Before a female is born, her body begins to develop eggs. During this prenatal period, cells in her ovaries divide until the first stage of meiosis, prophase I, is reaches. At this point, the cells go into a resting stage. At this point the cells go into a resting stage. At birth, a female has all the potential eggs she will ever have. About once a month in a sexually mature female, the process of meiosis starts up again in one of the prophase I c...
