Presentation on theme: "S EXUAL A NATOMY o Female-External o Female-Internal o Male-External o Male-Internal."— Presentation transcript:
S EXUAL A NATOMY o Female-External o Female-Internal o Male-External o Male-Internal
F EMALE INTERNAL SEX ORGANS The internal sexual organs of the human female: Ovaries Fallopian Tubes Uterus Vagina
O VARIES Defined: Female gonads that produce ova and sex hormones Each female has two ovaries about the size, shape, and texture of an irregular unshelled almond and dull gray in color. Located at the ends of the fallopian tubes on each side of the uterus. Attached to the uterus by ovarian ligaments, a type of connective tissue.
O VARIES Female Gonads ( Ovaries ) perform two major functions: Production of the female sex hormones estrogen and progesterone. Estrogen: Hormone responsible for typical female sex characteristics. Progesterone: Hormone that prepares and maintains the uterus for pregnancy. Production of mature ova ( egg cells ). At birth a female infants ovaries contain about 400,000 immature ova which is all the eggs she will ever have. Far more eggs than she will ever need During reproductive years only about four to five hundred ripened eggs will be released for possible fertilization
O VARIES Ovarian follicles: Small sacs containing ova. After maturing in the ovarian follicles, eggs are released ( usually one at a time ) during the process of ovulation.
O VARIES Ovulation : Discharge of a mature ovum from the ovary. Released egg is gently drawn from the surface of the ovary into the fallopian tubes which takes approximately 3 or 4 days which is the period in which a woman is fertile. Fertile: Time when pregnancy may occur Fertilize: Join male and female cells, sperm and ova, so that offspring develop If the egg is not fertilized during this time, it is expelled during menstruation.
F ALLOPIAN T UBES Defined: Ducts that connect the ovaries to the uterus. The twin fallopian tubes (oviducts) are hollow, muscular tubes approximately 10 centimeters or 4 inches long. Attached one on each side of the uterus. Extend outward from the uterus toward, but not attached directly to, the ovaries. Each funnel-shaped fallopian tube fans out into fingerlike extensions called fimbriae, which drape over the ovary.
F ALLOPIAN T UBES Fimbriae : Fingerlike projections at the end of the fallopian tube nearest the ovary that capture the egg and deliver it into the tube. Hairlike cilia on the fimbriae become active during ovulation, coaxing the egg from the ovary and propelling it down the length of the tube toward the uterus. If sperm are present, the egg may be fertilized while in the upper portion of the fallopian tube. If the fertilized egg does not proceed all the way to the uterus, tubal pregnancy may result.
F ALLOPIAN T UBES
U TERUS Defined: Hollow, muscular internal female organ in which the fertilized egg develops until birth. The uterus (womb) is a hollow, muscular organ shaped like an upside-down pear in which a fertilized egg implants and develops into a fetus. The uterus is suspended in the pelvic cavity by a number of flexible ligaments. Usually the uterus is positioned so that the top slants forward toward the abdomen (antroverted), although in about 10% of women the uterus tips backward toward the spine (retroverted). Retroverted uterus generally becomes antroverted spontaneously during the third month of pregnancy If a woman has not given birth the uterus is about 3 inches long, 3 inches wide, and bout an inch thick near the top and weighs about 2 ounces.
U TERUS No organ undergoes the same kind of dramatic change in adulthood as the uterus: It grows to 2 pounds by the end of pregnancy, independent of the weight of the fetus or placenta. After pregnancy it shrinks back almost (but not quite) to its original size.
U TERUS The uterus is divided into three major parts: Fundus: Uppermost part of the uterus Uterine Body: Central region of the uterus in which the fetus may develop Cervix: small, lower end of the uterus that protrudes into the vagina and opens slightly for the release of menstrual blood and even more so for the birth of a baby Viewed through the vagina the cervix of a woman who has never been pregnant appears like a smooth, pink disk with a small hole called the Os. Os: Opening in the middle of the cervix that leads to the interior of the uterus.
U TERUS Uterine wall is composed of three layers: Endometrium: Tissue that lines the inside of the uterine walls which is richly supplied with blood vessels and glands. It is the endometrial tissue that is expelled through the cervix an dvagina during menstruation. Myometrium: Smooth muscle layer of the uterine wall that gives the uterus strength and flexibility and is the source of the contractions necessary for childbirth. Perimetrium: Thin membrane covering the outside of the uterus.
VAGINA Defined: The stretchable canal that extends from the external genital opening to the cervix. Elastic, muscular tube that extends back and upward from the external vaginal opening to the cervix. Vagina has three major functions: Receptacle for the penis during sexual intercourse. Passageway for menstrual flow. Birth canal through which a fetus becomes a baby during childbirth.
V AGINA Vagina is a 3-5 inch long passageway built of skin, muscle, and fibrous tissue that extends at a 45 degree angle from the labia to the cervix. At rest the walls of the vagina lie against one another. During sexual arousal, the cervix lifts upward and the vagina expands in length to receive the penis. The width of the vagina is similarly flexible to accommodate many dimensions, from an incoming penis or tampon to an outgoing baby.
V AGINA The walls of the vagina consist of three layers: Vaginal Mucosa: Mucous membrane that is similar to the inside of the mouth. The cells of the vaginal mucosa are the source of vaginal lubrication that facilitates the insertion of a penis into the vagina during intercourse. Muscularis: Middle layer of the vaginal walls, is muscular and it is these muscles that contract during orgasm. Fibrous Layer: connects the vagina to other pelvic structures. Vaginal walls are richly supplied with blood vessels throughout, but the sensory nerve endings are concentrated in the lower third of the vagina nearest the vaginal entrance.
B REASTS Breasts consist of 15 or 20 clusters of mammary glands, each with a separate opening to the nipple, surrounded by fatty and fibrous tissue. Nipple - where milk ducts open; at the tip of the breasts. Areola - area surrounding the nipple.