Final answer:
As men age, there can be a decrease in sexual response due to declines in Leydig cell activity and reduced testosterone concentrations. Women experience a decline in fertility that peaks in their twenties and ends with menopause. However, individuals can still enjoy sex well into later years.
Step-by-step explanation:
As men age, there can be a decrease in sexual response due to declines in Leydig cell activity, which can occur around 40 to 50 years of age. This leads to a reduction in circulating testosterone concentrations, resulting in symptoms of andropause, also known as male menopause. Symptoms of andropause include fatigue, reduced muscle mass, depression, anxiety, irritability, loss of libido, and insomnia. Reduced fertility and sexual dysfunction can also be associated with andropause.
In women, fertility peaks in their twenties and slowly declines until around 35 years of age. After that, fertility declines more rapidly until menopause, the cessation of the menstrual cycle. Menopause occurs as a result of the loss of ovarian follicles and leads to the end of female fertility. Low levels of estrogen and progesterone during menopause can also be associated with certain diseases, such as osteoporosis, atherosclerosis, and abnormal blood lipid levels.
Overall, sexual response may vary with age, but it is important to note that individuals can continue to enjoy sex well into their later years, and research suggests that as many as one in five new cases of AIDS occurs in adults over sixty-five years old.