Sunday, February 15, 2015

Human sexual anatomy, physiology, and development

o Sex hormones exert organizing and activating effects.

- Organizing effects during a sensitive period of early development permanently influence genital anatomy and the brain.
* The genital organs begin to form identically until the second trimester of pregnancy during which the genetic components of the fetus dictate which parts of the anatomy will grow to develop male or female patterns.

- Activating effects are transient and may occur at any time.
* Sexual arousal can be controlled by altering hormone levels.
~ Some sex offenders have been treated this way by being given cyproterone, a drug that blocks the binding of testosterone to receptors in cells.
~ They experience decrease in sexual fantasies and offensive sexual behaviors.
~ Side effects include depression, breast growth, weight gain, and blood clots.
~ They also wear off quickly if offender stops taking daily pill.


o Sex hormones activate specific sexual and parental behaviors.


o Female initiated sexual activities during the monthly cycle are similar, showing biological impact of hormone levels, typically peaking during ovulation.


o Puberty:
- The onset of sexual maturity
- Menarche
* A girls first menstruation
- Puberty starts when the hypothalamus begins to release lutenizing hormone releasing hormone at the rate of one burst per hour.
* Hormone stimulates the pituitary to send signal to gonads to release either estrogen or testosterone.
* The sex hormones stimulate growth spurts in secondary sexual characteristics such as breast development and broadening of hips in women and lowering voice and broadening of shoulders in men.

o Menopause
- The time when women permanently stop menstruating.
- Estrogen replacement therapy shows better performance in memory tasks.