Menopause is accompanied by a sharp and sustained rise in the production of GnRH (Gonadotropin-releasing hormone) released by the hypothalamus. This causes an increase in the secretions of FSH and LH (luteinizing hormone released by the anterior pituitary gland that assists FSH), while circulating concentrations of estrogen and progesterone decline. While the female is no longer able to reproduce after menopause, the male is still capable well into his 80s or longer.
By the age of 50 in the female, declining estrogen levels have reduced the size of the uterus by 50%. The decline in estrogen levels also reduces the size of the breasts and thins the urethral and vaginal walls. This reduction has also been linked to the development of osteoporosis.
In addition, the risk of atherosclerosis and other forms of cardiovascular disease increases after menopause. The ligaments that anchor the uterus, urinary bladder, and rectum weaken, allowing these organs to drop down to where surgical correction may be needed.
The decrease in estrogen secretion also causes a change in the accessory reproductive organs. Tissues become thinner, decreasing secretions, and thus increasing the risk of such disorders as vaginal infections. The decline in estrogen secretions is also thought to contribute to bone weakening, causing osteoporosis and an increase in cardiovascular diseases.
Changes also occur in breast tissue, with the supporting ligaments weakening. Fibrous cells replace glandular cells and the amount of fat tissue decreases. All these changes cause breast tissue to sag.
Secondary sex characteristic changes occur in hair and body fat distribution. Because of lowered levels of sex hormones, people age 90-100 of both sexes and all races look very much alike.
Changes in the male occur gradually over a longer period of time and are known as the male climacteric.
Circulating testosterone levels in the male begin to decline between the ages of 50 and 60. Increases in FSH and LH levels occur at the same time, leading to a decline in sexual activity.
Although sperm production continues, there is a gradual reduction in sexual activity, caused in part, by a declining testosterone and sperm production.
