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Our Sexual And Reproductive Anatomy. The External Female Anatomy The Internal Female Anatomy The External Male Anatomy The Internal Male Anatomy The Brain Our Sexual Bodies. The External Female Anatomy.
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Our Sexual And Reproductive Anatomy The External Female Anatomy The Internal Female Anatomy The External Male Anatomy The Internal Male Anatomy The Brain Our Sexual Bodies
The External Female Anatomy • The vulva consists of the mons veneris, the labia majora, the labia minora, the clitoris, and the vaginal and urethral openings.
The Mons Veneris • The term refers to the soft layer of fatty tissue overlaying the area where the pubic bones come together.
The Labia • The labia consist of two outer (labia majora, two major lips) and elongated folds of skin, which, in the sexually unstimulated state cover the vaginal and urethral openings. • The labia minora, which meet at the top too form the clitoral hood, are very sensitive to touch. They have numerous blood vessels that become engorged with blood during sexual stimulation, causing them to swell and turn bright red or wine-colored.
Located at the base of the labia minora are the Bartholin’s glands, which, during prolonged stimulation, contribute a few drops of an alkaline fluid to the inner surfaces via ducts.
The Clitoris • The clitoris develops from the same embryonic tissue as the penis and has at least as many nerve endings as the much larger penis, making it extremely sensitive to touch. In fact, it is the only structure in either men or women with no known function other than to focus sexual sensations.
The Vaginal Opening • The area between the two labia minora is sometimes referred to as the vestibular area and the vaginal opening as the introitus. • The vaginal opening, which is very sensitive to stimulation, is not a permanently open orifice always ready for penetration by the penis. • It is surrounded by the bulbocavernosus muscle, a ring of sphincter muscles similar to the sphincter muscles surrounding the anus.
Sexually experienced women can learn to voluntarily contract or relax these muscles during intercourse, and during childbirth the vaginal opening expands enough to accommodate delivery of a baby. • In sexually inexperienced women, a thin membrane called the hymen may partially cover the opening to the vagina. • The hymen has no known physiological function, but the presence of the hymen has been used by men throughout history as proof of virginity.
The Urethral Opening • Urine passes from the bladder through a small tube called the urethra and out the urethral opening, with is located below the clitoris and above the vaginal opening. • A man’s urethra serves for the passage of sperm as well as urine, but a woman’s urinary system is not related to her reproductive system. • Cystitis is an inflammation of the bladder with symptoms of frequent and burning urination. Thus, after a bowel movement, a woman should not wipe herself in the direction from the anus to the vulva.
The Breasts • Breasts develop at puberty as a result of increasing levels of the hormone estrogen, which is produced by the ovaries. Thus, the breasts are really a secondary sex characteristic, just as pubic hair is. Interestingly, it is common for one breast to be slightly larger than the other. Boys also have a slight increase in estrogen levels after puberty, and many show a slight increase in breast size as a result.
Each adult breast consists of 15 to 20 mammary glands. • In the late stage of pregnancy, a hormone called prolactin from the pituitary gland causes the mammary glands to start producing mild. • About half of all cases of breast cancer have spread beyond the breast before they are discovered. • However, with early detection, there is a 96% survival rate, and with little instruction, the woman herself is the one most likely to make a life-saving early detection.
The American Cancer Society recommends that women should examine their breasts on a monthly basis starting at age 20. The best time is immediately after menstruation ends, when estrogen levels are low and the breasts are not tender or swollen. • The American Cancer Society suggests a mammogram every 1 to 2 years between the ages of 40-49, and an annual breast X-ray after the age of 50.
Should you have a lump and it is diagnosed as cancerous, a number of surgical procedures might be performed: • 1)radical mastectomy, in which the entire breast, underlying muscle, and lymph nodes are removed; • 2)simple mastectomy, in which only the breast is removed; and • 3) lumpectomy, in which only the lump and a small bit of surrounding tissue are removed, followed by radiation therapy.
Internal Female Anatomy • Vagina- the sheath-like canal in a woman that extends from the vulva to the cervix and that receives the penis during intercourse.
The Vagina • The inner layer has a soft mucosal surface similar to that of the inside of the mouth. Before puberty, the walls of the vagina are thin and relatively inelastic. The rising levels of female hormones at puberty cause the vaginal walls to thicken and become more elastic and highly vascularized. • At menopause the ovaries atrophy, and the consequent loss of hormones causes the walls of the vagina to again become thin and inelastic, similar to their condition before puberty.
The vagina is a self-cleansing organ. Many potentially harmful bacteria from the outside environment are destroyed by other bacteria that are found naturally within the vagina.
The Uterus • It is within the uterus, or womb, that a fertilized egg will attach itself and become an embryo and then a fetus. • The uterus has three layers: the innermost endometrium, where the fertilized egg implants; a strong middle layer of muscles called the myometrium, which contracts during labor; and an external cover called the perimetrium.
The endometrium thickens and become rich in blood vessels after ovulation, but it is sloughed off and discharged from the woman’s body during menstruation if fertilization does not occur.
The Fallopian Tube • Extending 4 inches literally from both sides of the uterus are the Fallopian tubes, or oviducts, as they are sometimes called. • After an egg is expelled from an ovary into the abdominal cavity at ovulation, it is picked up by one of the fimbria. If a sperm fertilizes the egg, it will usually do so within the tube. The fertilized egg then continues its 3- to 4-day trip through the tube and normally implants itself in the endometrium of the uterus.
The Ovaries • The ovaries have two functions: to produce eggs, or ova, and to produce female hormones. At birth, a girl has all the immature eggs that she will ever have, about 300,000 to 400,000 in each ovary.
Cancer of the Cervix • The American Cancer Society advises women that regular checkups should begin when they start having sexual.
Cancer of the Endometrium and Ovaries • Cancer of the endometrium is also very common with an estimated 40,100 new cases and 6,800deaths per year in the U.S. Typically, the first symptom is abnormal vaginal bleeding, so if you should experience this, go to a physician immediately.
The Penis: Outer Appearance • The penis had both a reproductive and a urinary function. It serves to deposit sperm in a woman’s vagina and also to eliminate urine from the bladder. • At birth the foreskin folds over the glans, the smooth rounded end of the penis, but many men have had their foreskin cut off in a surgical procedure known as circumcision.
The Penis: Internal Structure • The penis has three parts: the body or shaft; the glans; and the root. In cross section, the shaft of the penis can be seen to consist of three parallel cylinders of spongy tissue, two corpora cavernosa on top and a corpus spongiosum on the bottom. • The raised rim at the border of the shaft and glans is called the corona (and is the most sensitive to touch of any part of the penis.
The root of the penis consists of the expanded ends of the cavernous bodies, which fan out to form crura and attach to the pubic bone, and the expanded end of the spongy body.
The Scrotum • The sac located beneath the penis is called the scrotum. It holds the testicles outside of the body cavity. Sperm are produced in the testicles, but they can only be produced in an environment several degrees lower than the normal body temperature of 98.6 degrees Fahrenheit.
The Testicles • Like the ovaries, the testicles have two functions: to produce sperm and to produce male hormones. Millions of new sperm start to be produced each day in several hundred seminiferous tubules. Each tubule is 1 to 3 feet in length, and if they were laid together end to end they would measure over one quarter of a mile in length.
In between the seminiferous tubules are cells called interstitial cells of Leydig, which produce male hormones. Male hormones are called androgens. • The most important is testosterone. Another hormone produced in the testicles is called inhibin. • The virus that is responsible for mums, for example, causes the testicles to swell painfully, and the pressure against the fibrous sheath can crush the seminiferous tubules, resulting in sterility if mumps occurs after puberty.
The Duct System • The seminiferous tubules converge to form the epidiymis, coiled tubes that can be felt on the top and back of each testicle. Sperm mature as they travel though the epididymis, which takes up to 6 weeks. From here the sperm pass into the paired 14-16 inch vas defrens. • The two ejaculatory ducts open into the urethra, which passes through the spongy body of the penis.
The Prostate Gland and Seminal Vesicles • The prostate gland secretes many substances that cause the semen to temporarily coagulate after ejaculation, thus helping to prevent spillage from the vagina. The prostate also secretes a powerful antibiotic, possibly to protect the male and female reproductive systems from infection.
The Cowper’s Glands • The Cowper’s, or bulbourethral, glands are two pea-sized structures located beneath the prostate. They secrete a few drops of alkaline fluid that may appear at the tip of the penis prior to orgasm.
The Brain • The cortex is the part of the brain that allows us to think and reason. It is also the anatomical origin of our sexual thoughts and fantasies. • The limbic system structures are where emotions and feelings originate. • These structures apparently are also important for sexual behaviors. • Male animals with this kind of brain damage will persistently mount not only females but also males and animals of other species.
The hypothalamus receives its major input from the limbic system structures. Destruction of certain areas of the hypothalamus completely eliminates sexual behavior in laboratory animals. On the other hand, if electrodes are placed in certain areas of the hypothalamus or limbic system of rats and the animals are allowed to press a lever to deliver electrical stimulation, they will press continuously for hours until they drop from exhaustion.
Our Sexual Bodies • Kissing is an important part of our sexual relations for most people in Western culture. • Hair is a very important part of our sexual anatomy. • Eye contact between two people can be an initial and ongoing form of sexual communication. • A person’s voice, feel, taste, smell, and personality can all be sensual and contribute to his or her sexuality.
It has been found that having positive sexual experiences is a good way to start feeling satisfied with your body. So, find a partner who appreciates you for who you are and how you look, and vice versa, and learn to feel good about yourself.
