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Important functions of the body are regulated by the neuroendocrine complex consisting of two major control systems the nervous system and the endocrine system.These two systems function in close collaboration and integration and regulate functions such as reproduction including sexual behavior.
Some of these effects will be discussed here: The most important hormone in sexual function is testosterone. This hormone, sometimes called the male sex hormone, is actually present in both sexes.In a normal man, 6 to 7 mg of testosterone are produced per day. With more than 95 percent manufactured in the testes and the remainder in the adrenal glands. From the point of view of reproduction and sexual behavior, are the hormones released from 1. Anterior pituitary
2. Gonads
3. Hypothalamus. In addition to their varied effects on metabolism: 1. Development of secondary sex characteristics
2. Mensuration
3. Maintenance of pregnancy
4. Lactation in females
5. Spermatogenesis in males
6. Hormones also affect
7. Sexual desire
8. Libido
9. Appetite
10.Sexual arousability & responses In a women, approximately 0.5 mg of testosterone is produced daily in the ovaries and the adrenals.Testosterone is the principal biologic determinant of the sex drive in both men and women. Deficiency of testosterone may cause a drop in sexual desire, and excessive testosterone may heighten sexual interest.In men, too little testosterone may cause difficulty obtaining or maintaining erections, but it is not certain whether testosterone deficiencies interfere with female sexual functioning apart from reducing sexual desire. Estrogens, sometimes called female hormones, are also present in both sexes and are made primarily in the ovaries in women and in the testes in men.In women, they are important from a sexual view point in maintaining the condition of the vaginal lining and in producing vaginal lubrication.Estrogens also help to preserve the texture and function of the female breasts and the elasticity of the vagina.In men, estrogens have no known function. Too much estrogen in males however, dramatically reduces the sexual appetite and can cause difficulties with erection and enlargement of the breasts.Progesterone, a hormone structurally related to both the estrogens and testosterone, is also present in both sexes. It is now clear that the regulatory role of the pituitary is more like a relay station and that a portion of the brain itself – the hypothalamus – has primary control over most endocrine pathways.The hypothalamus produces a substance called gonadotropin releasing hormone (GnRH) that controls the secretion of two hormones made in the pituitary gland that act of the gonads (ovaries and testes). Luteinizing hormone (LH) stimulates the Leydig cell in the testes to manufacture testosterone in the female, LH serves as the trigger for ovulation release of an egg from the ovary). Follicle stimulating hormone (FSH) stimulates the production of sperm cell in the testes, in the female; FSH prepares the ovary for ovulation.
1. LATE ADULTHOOD
2. The psychological need for intimacy, excitement, and pleasure does not disappear in old age, and there is nothing in the biology of aging that automatically shuts down sexual function.
3. Biological considerations
4. Aging alone does not diminish female sexual interest or the potential of the women to be sexually responsive if her general health is good.
5. Clitoral response is not affected by aging, vaginal function changes in two different ways.
6. First, reduced elasticity in the wall of the vagina leads to less expansion during sexual arousal.
7. Second, vaginal lubrication Recent research has shown that the decrease in vaginal lubrication in postmenopausal women is the direct result of diminished vaginal blood flow that, in turn, is caused by low estrogen.
8. The normal pattern of reproductive aging in men is quite different from women because there is no definite end to male fertility.
9. Although sperm production slows down after age forty it continues into the eighties and nineties.
10. Similarly, while testosterone production declines gradually from age fifty-five or sixty on, there is usually no major drop in sex hormone levels in men as there is in women.
11. About 5 percent of men over sixty, experiences a condition called the male climacteric, which resembles the female menopause in some ways.
12. (Using the term “male menopause” to describe the male climacteric is incorrect since men do not have menstrual periods). 13. This condition is marked by some or all of the following features: Weakness, tiredness, poor appetite, decrease sexual desire, reduction or loss of potency, irritability and impaired ability to concentrate. 14. These changes occur because of low testosterone production, and they can be reversed or improved by testosterone injections or capsules (Nuvir). 15. The physiology of male sexual response is affected by aging in a number of ways. The following changes have been noted in men over fifty – five: 16. It usually takes a longer time and more direct stimulation for the penis to become erect: 17. Erections tend to be less firm, on average, than at earlier ages: 18. The testes elevate only partway up to the perineum, and do so more slowly than in younger men: 19. The amount of semen is reduced, and the intensity of ejaculation is lessened. Prolactin and Male Sexuality This has been shown that the state of hyperprolactinaemia in men is usually associated with sexual impairment and a reduction in prolactin level leads to improvement of sexual functions. Prolactin is reduced by drug BROMOCRYPTINE
The MENOPAUSE • With aging, all women reach an end to their fertility. First, there is a gradient decline in female reproductive capacity from age thirty on reflecting both a drop in fertility and a higher rate of miscarriages. In addition, abnormalities of the menstrual
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