Hormones and Sexuality

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					 Hormones and Sexuality
        The Endocrine System
         The Menstrual Cycle
    Length of the Menstrual Cycle
 Menstrual Synchrony and Pheromones
Attitudes About Menstruation: Historical
 Attitudes About Menstruation Today
         Menstrual Problems
    Regulation of Male Hormones
     Hormones and Sexual Desire
         The Endocrine System
• Hormones play a crucial role in both men and
  women. They are important for growth,
  metabolism, water retention, reaction to stress, and
  many other functions.
• Hormones are chemical substances that are
  released into our bloodstream by ductless glands.
  They are carried in the blood to other parts of the
  body where they exert their effects. Hormones
  released by one gland often cause another gland to
  release its own hormones. This network of
  ductless glands is called the endocrine system.
• The testicles and the ovaries are part of the
  endocrine system. The testicles manufacture and
  release testosterone, and the ovaries produce
  progesterone and estrogen.
• The pituitary gland releases eight different
  hormones into the bloodstream. Two of these
  have their effect on the ovaries and testicles, and
  are thus called gonadotropins.
• In women, follicle-stimulating hormone
  stimulates the maturation of a follicle in the
• A second pituitary gonadotropin hormone is called
  luteinizing hormone. In women, LH triggers
  ovulation. In men, it stimulates the testicles to
  produce male hormones.
          The Menstrual Cycle
• An ovum is surrounded by other cells within a thin
  capsule of tissue to form a follicle.
• At birth, each ovary has about 300,000 to 400,000
  immature follicles, and the ovaries do not produce
  any new follicles during a woman’s lifetime.
• The average length of an adult human menstrual
  cycle is about 28 days.
 Preovulatory Phase (Day 5 to 13)
• This phase is also referred to as the follicular or
  proliferative phase.
           Ovulation (Day 14)
• The LH surge signals the onset of ovulation within
  12 to 24 hours.
• At ovulation, the follicle ruptures and the ripe
  ovum is expelled into the abdominal cavity, where
  it will soon be picked up by a Fallopian tube.
Postovulatory Phase (Days 15 to 28)
• If the egg is fertilized by a sperm, it continues its
  trip through the Fallopian tube and implants itself
  in the endometrium.
     Menstruation (Days 1 to 14)
• With the decline in levels of estrogen and
  progesterone, there is loss of the hormones that
  were responsible for the development and
  maintenance of the endometrium.
   Length of the Menstrual Cycle
• Most women have cycles that vary in length by 8
  days or more.
      Menstrual Synchrony and
• They were attracted by natural body scents called
  pheromones. Pheromones are defined as “a
  substance secreted by an animal to the outside of
  that individual which is then received by another
  individual…of the same species, which then elicits
  some behavioral or development response in the
   Attitudes About Menstruation:
       Historical Perspectives

• The biblical Hebrews regarded a menstruating
  woman as “unclean” or “impure,” and believed
  that she could transfer her condition of
  uncleanliness to a man during sexual intercourse.
   Attitudes About Menstruation
• Myths that women should avoid bathing,
  swimming, and exercise during menstruation are
• Bathing, washing their hair and swimming are not
  the only things many women do without during
• The discharge consists of nothing more than some
  sloughed off endometrial tissue, mucus, and a
  small amount of blood.
• Amenorrhea refers to the absence of menstruation
  for 6 months or longer. Oligomenorrhea is the
  absence of menstruation for shorter intervals, or
  unevenly spaced menstrual periods.
• Girls with high body fat levels generally start
  menstruating at a younger age than girls with low
  levels of body fat.
• Amenorrhea is common among female athletes.
  Women with the eating disorder anorexia nervosa
  are often considerable under weight, and as a
  result rarely menstruate.
• While poor health can result in amenorrhea,
  amenorrhea can also affect a woman’s health.
• For example, the low levels of estrogen usually
  associated with amenorrhea often result in long-
  term problems such as osteoporosis and
  cardiovascular disease.
• Thus, a premenopausal woman who is not
  menstruating regularly should consult a physician.
  Premenstrual Syndrome (PMS)
• PMS refers to a group of physical and/or
  emotional changes that many women experience
  in the last 3 to 14 days before the start of their
  menstrual period.
• Only about 75% of women with regular menstrual
  cycles have some symptoms.
• To be diagnosed with PMDD, a woman’s
  symptoms must “markedly interfere” with social
  relations, work, or education, and include at least
  one of the following symptoms: markedly
  depressed mood, marked anxiety or tension,
  persistent and marked irritability or anger, or
  “marked affective lability” (extreme changes in
  mood, such as sudden sadness).
• It is estimated that 3 to 8% of all women in their
  reproductive years have PMDD.
• Symptoms can include backaches, headaches, a
  feeling of being bloated, and nausea.
• Endometriosis refers to a condition in which the
  endometrial tissue also grows outside the uterus.
    Toxic Shock Syndrome (TSS)
• TSS is caused by toxins produced by a bacterium.
 Regulation of Male Hormones
• In men, the hypothalamus, pituitary gland, and
  testicles operate in a feedback loop much like the
  feedback loop in women.
    Hormones and Sexual Desire
• Research on sex and hormones relies heavily on
  two types of studies: those investigating the
  effects of administering hormones and those
  investigating the effects of a loss of hormones.
• After puberty in boys, 6 to 8 milligrams of
  testosterone are produced every day, and among
  very young adolescent boys, sexual activity
  increases as testosterone levels increase.
• There is a decline in testosterone production as a
  man grows older, but men who are sexually active
  often have high testosterone levels.
• Hypogonadal men show very little interest in sex.
• In some parts of the world, men who were once
  used as harem attendants were forced to have their
  testicles removed so that they would not be
  interested in the women they were supposed to
• In many cases this worked, especially if the men
  were not yet sexually experienced at the time of
• However, there were also stories of some eunuchs
  having the time of their lives, like roosters
  guarding a hen house.
• Modern studies of castrated men show, however,
  that sex drive and behavior are drastically or
  completely suppressed in a high percentage of
• In Europe and in the United States, some judges
  now offer male sex offenders a choice between
  prison and chemical castration with antiandrogen
  drug called DepoProvera. This drug and others
  like it severely reduce testosterone production, and
  often reduce interest in sex.
• What about women? The loss of estrogen and
  progesterone at menopause does not reduce sexual
  desire in most women. In those postmenopausal
  women who do show a decrease, estrogen
  replacement therapy alone generally has no effect.

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