human repro

• Reproduction myths and legends


  Stories that attempt to explain the process of human conception and childbirth, often involving fantastical elements or supernatural beings
• Purposes of reproduction myths and legends

  • Help people understand the natural world, cope with uncertainty of life, provide comfort and hope
  • Teach moral lessons and reinforce cultural values
• Reproduction myths and legends from around the world

  • Ancient Greece: Athena born from Zeus's head
  • Ancient Egypt: Horus born from Osiris's thigh
  • Maori mythology: First woman Hine-ahu-one created from earth
  • Native American: Babies come from spirit world
  • Christian: Eve created from Adam's rib, Virgin Mary impregnated by Holy Spirit
• Reproduction myths and legends are not based on scientific evidence
• Overall function of the reproductive system


  To produce offspring
• Main parts of the reproductive system

  • Gonads
  • Internal genitalia
  • External genitalia
• Female reproductive system


  • Ovaries
  • Oviducts
  • Uterus
  • Vagina
  • Vulva
• External parts of female reproductive system (vulva)

  • Labia majora
  • Labia minora
  • Clitoris
  • Urethra
  • Vagina
  • Hymen
• Internal parts of female reproductive system

  • Ovaries
  • Oviducts
  • Uterus
  • Vagina
• Male reproductive system


  • Scrotum/scrotal sac
  • Testicles/testes
  • Epididymis
  • Vas deferens
  • Urethra
  • Penis
  • Seminal vesicle
  • Prostate gland
  • Cowper's gland
• Sex hormones


  Chemical messengers produced by endocrine glands that play an essential role in sexual development and reproduction
• Female sex hormones


  • Estrogen
  • Progesterone
  • Testosterone
• Male sex hormones


  • Androgens, especially testosterone
• Human sexual response cycle

  Pattern of physiologic events occurring during sexual arousal and intercourse, including desire, excitement/arousal, plateau, orgasm, and resolution
• Stages of human sexual response cycle

  • Desire
  • Excitement/arousal
  • Plateau
  • Orgasm
  • Resolution
• Excitement/arousal stage


  Sexual arousal usually begins in the brain and can be stimulated by thought, fantasy, conversation, senses, etc. Involves physiological changes like increased heart rate, blood pressure, muscle tension, and genital changes
• Plateau stage


  Continued growth of physical and emotional excitement, can feel intoxicating and make it difficult to make intentional decisions
• Orgasm


  Intense, pleasurable feeling that occurs at the end of the plateau phase, involving a release of sexual and muscular tension through a series of quick contractions
• Resolution stage


  Reverses the physiological changes of the previous stages
• Orgasm


  The peak of sexual arousal, when the sexual and muscular tension (especially those in the pelvis) built up is released in a series of quick pleasurable contractions
• Not all sexual experiences result in orgasm; this is normal
• There is often a lot of pressure to achieve orgasm during sex and if a person does not experience this, they may feel inadequate or as if they've done something wrong
• Ejaculation (male)


  • Each ejection is accompanied with continuous sexual pulses
  • The first and second convulsions are usually the most intense in sensation and produce the greatest quantity of semen. Thereafter, each contraction is associated with a diminishing volume of semen and a milder sensation of pleasure
• Orgasm (female)


  • Uterine and vaginal contraction
  • Increase in vaginal lubrication, a tightening of the vaginal walls and overall pleasure
  • Possibility of female ejaculation
• Resolution


  Reverses the previous phase: muscles relax, breathing slows, the penis returns to its normal size
• Neurotransmitters


  Chemical messengers that help the brain communicate with other areas of the body
• Neurotransmitters involved in sexual pleasure

  • Prolactin
  • Dopamine
  • Oxytocin
  • Serotonin
  • Norepinephrine
• Insufficient lubrication, history of trauma or abuse, lack of arousal, boredom with sex or one's partner, sexual interactions that do not conform to a person's specific sexual desires or interests, and sexually transmitted infections can affect sexual pleasure across all genders and sexual orientations
• Sexual differentiation


  The process by which a person develops into either a male or a female
• Chromosomal sex


  In humans, DNA is organized into 46 chromosomes, with one set of 23 chromosomes coming from the mother and the other set coming from the father. Males have XY chromosomes, females have XX chromosomes
• Autosomal chromosomes


  Twenty-two pairs of chromosomes that are similar in length and have the same genes present at the same location regardless of if they are received from the mother or father
• Sex chromosomes


  The last pair of chromosomes that is responsible for determining if an individual becomes a male or female
• Allele


  A variant or alternative form of a gene
• Recessive allele


  Will only produce a phenotype if there is no dominant allele present
• Genotype


  The actual or complete genetic makeup of an organism
• Phenotype


  An individual's observable traits, determined by both their genomic makeup (genotype) and environmental factors
• When a boy or man ejaculates, only about a teaspoon of semen (the fluid that contains sperm) comes out, containing somewhere between 250 and 500 million sperm
• People of any gender can experience multiple orgasms
• If someone with a penis has an erection and does not ejaculate, it does not cause any physical harm, just slight discomfort
• During vaginal sex, the partner with a penis does not urinate a little inside their partner's body