SExUAL AROUSAL MOD 6

• Widespread communication throughout the body is accomplished through the release of hormones.
• Two kinds of hormones

  Steroid hormones

  Sex hormones
• STEROID HORMONES

  ARE DERIVED FROM CHOLESTEROL, CONTAIN FOUR CARBON RINGS AND EXERT THEIR EFFECTS IN THREE WAYS.
• Binding to membrane receptors like neurotransmitters.
• Entering cells and activate certain kinds of proteins in the cytoplasm
• Binding to chromosomes where they activate or inactivate certain genes
• SEX HORMONES


  are a special kind of steroids, released mostly by the gonads and to a lesser degree by the adrenal glands. Affect the brain, genital and other organs
• Two types of sex hormones

  • Androgens
  • Estrogens
• TESTOSTERONE


  The most widely known androgen
• ESTRADIOL


  The most prominent type of estrogen
• PROGESTERONE


  another predominantly female hormone, prepares the uterus for the implantation of a fertilized ovum and promotes the maintenance of pregnancy.
• Very few people have a brain that is male-typical or femaletypical in all regards.
• almost anyone’s brain is a mosaic of male-typical, female-typical, and approximately neutral areas
• most people have a mixture of male-typical, female-typical, and neutral interests, attitudes, and activities.
• Testosterone


  essential for male sexual arousal, acts partly by increasing touch sensitivity in the penis
• Sex hormones also bind to receptors that increase responses in parts of the hypothalamus, including the ventromedial nucleus, the medial preoptic area (MPOA), and the anterior hypothalamus
• Testosterone primes the MPOA and several other brain areas to release dopamine
• MPOA neurons release dopamine strongly during sexual arousal, and the more dopamine they release, the more likely the male is to copulate
• Levels of testosterone correlate positively with men’s sexual arousal and their drive to seek sexual partners.
• Researchers found that, on average, married men and men living with a woman in a committed relationship have lower testosterone levels than single, unpaired men of the same age
• Castration (removal of the testes)


  generally decreases a man’s sexual interest and activity.
• The hypothalamus and pituitary interact with the ovaries to produce the menstrual cycle
• A woman’s menstrual cycle depends on a feedback cycle that controls the release of several hormones
• Female's sexual desire is greatest during the fertile period of the menstrual cycle, when estradiol levels are high
• Oxytocin


  s a pituitary hormone also important for reproductive behavior
• OXYTOCIN

  •Stimulates contraction of the uterus during delivery of a baby •Stimulates the mammary gland to release milk.

  •Released during orgasm and triggers a state of complete relaxation. •Facilitates formation of pair bonds between mating partners and mother and infant