Sexual Anatomy

• Sex


  From the Latin word 'secare' which means to cut / to divide
• Sex (usually assigned)


  Refers to the declaration of a baby's sex made by a doctor, midwife or a birthing assistant based on the observable genitalia of a baby
• Sex


  Refers to the biological characteristics distinguishing male and female
• Most individuals are clearly female or male by all five physical criteria. However, a minority fall somewhat short for this test and their sex is therefore AMBIGUOUS (INTERSEXUALS/ INTERSEX OR DSDs)
• Male symbol


  Taken from the symbol of the planet Mars, associated with shield and spear
• Female symbol


  Taken from the symbol of the planet Venus, associated with hand mirror
• Eighteenth century botanist, Carl Linnaeus was actually the first in recorded history to use these symbols in reference to gender
• These symbols were largely inherited from the International Federation of Eugenic Organizations in 1932 by the Sociological Research Committee of the Royal Anthropological Society of Great Britain
• Sexual Dimorphism


  Characteristic differences in form between males and females
• Factors in determining a person's sex

  • Biological aspects
  • Psychosocial
• Chromosomal sex


  Typical: cells of a female body contain two X chromosomes (XX); the cells of a male body contain one X and one Y chromosome (XY)
• Chromosomal sex abnormalities


  Atypical: XXY, XYY, XXX (Turner Syndrome and Klinefelter Syndrome)
• Turner Syndrome


  Occurs when females inherit only one X chromosome. Symptoms include short stature, non-functioning ovaries, webbed neck, lymphedema, skeletal abnormalities, heart defects, high blood pressure, and kidney problems
• Klinefelter Syndrome


  Chromosomal change resulting in one or more extra X chromosomes in each of the body's cells
• Gonadal sex


  Typical: female body has ovaries, male body has testicles. Atypical: in rare cases, ovarian and testicular tissue is found in the same body

  
• Hormonal sex


  Typical: gonads produce 'female' and 'male' hormones that play an important role in development. Atypical: too much or too little 'female' and 'male' sex hormones can lead to atypical physical appearance
• Internal accessory reproductive structures

  Typical: female body has oviducts, uterus, vagina. Male body has sperm ducts, seminal vesicles, prostate. Atypical: rare cases, these organs are underdeveloped or missing

  
• External sex organs


  Typical: female body has clitoris, labia, vagina. Male body has penis and scrotum. Atypical: in rare cases, these organs are underdeveloped or missing, or both are present (intersex)

  
• Sex of assignment or rearing

  Typical: a child with a female body will usually be raised as a girl, a child with a male body will usually be raised as a boy. Atypical: it is possible to raise a female child as a boy and a male child as a girl
• Sexual self-identification


  Typical: a child with a female body raised as a girl will usually consider herself female, a child with a male body raised as a boy will usually consider himself male. Atypical: cases of children with female bodies raised as girls who nevertheless consider themselves male, and vice-versa
• Primary sex characteristics


  Body structures directly concerned in reproduction, such as testes, ovaries, and external genitalia
• Secondary sex characteristics


  Manifestations specific to each sex that are incipient at puberty but not essential to reproduction, such as development of breasts or beard, muscularity, distribution of fat tissue, and change of pitch in voice
• Penis


  • Serves important functions in sexual pleasure, reproduction and elimination of body wastes by urination
  • 3-5" in the flaccid state, 5-7" in the erect state
  • Glans is covered by foreskin and contains 4,000 nerve endings
  • Shaft is divided into sections of tissues called corpora cavernosa and corpora spongiosum
  • Root extends to the pelvis and attaches to pelvic muscles
• Contrary to popular belief, the penis does not contain a muscle and no muscle is involved in erection. The common belief that the penis of the human male contains a bone is also not true.
• Foreskin or prepuce


  Additional layer of skin which forms a sheath-like covering over the glans. It may be present or absent in the adult male, depending on whether he has been circumcised.
• Circumcision


  Cutting away or removal of the foreskin for cultural, religious and medical reasons
• Testicles (Testes/gonads)


  • Part of the internal genitals, male sex glands located behind the penis in the scrotum
  • Produce and store sperm, and are the body's main source of male hormones (testosterone)
  • Seminiferous tubules manufacture sperm, interstitial cells manufacture testosterone
• Scrotum and Testes


  Can move up and close to the body or down and away from the body to maintain a fairly constant temperature slightly lower than normal body temperature, which is necessary to protect the sperm
• Erection


  Stiffening of the penis due to blood engorgement
• Ejaculation


  Expulsion of seminal fluid from the penis, occurring in two stages: emission phase (accumulation of seminal fluid at the base of the penis) and expulsion phase (series of muscle contractions during orgasm that propel the fluid out)
• Refractory Period


  Recovery phase after orgasm during which it is physiologically impossible for a man to have additional orgasms
• Semen (seminal fluid)


  Fluid expelled during orgasm, a mixture of secretions from the epididymis, seminal vesicle, prostate and bulbourethral gland
• Dartos muscle


  Located in the middle of the scrotum, makes the movement possible
• Physiology of Male sexual and reproductive response

  1. Erection

  2. Ejaculation
• Ejaculation


  1. Emission phase

  2. Expulsion phase
• Emission phase


  Accumulation of seminal fluid at the base of the penis
• Expulsion phase


  Series of muscles contractions which occur during orgasm and propel fluid out of the penis
• Refractory Period


  Period following ejaculation and lasting anywhere from 10 minutes to a few hours, recovery phase after orgasm during which it is physiologically impossible for a man to have additional orgasms
• Major constituents of semen

  • Sperm
  • Fructose
  • Clotting and anticoagulant factors
  • Prostaglandins
  • Spermine
• Fructose


  Produced by the seminal vesicle and provides energy for the sperm