third

• Fertilization and meiosis


  Alternate during the entire life cycle
• Zygote development


  1. Develops into an embryo

  2. Grows into an adult
• Gametes


  Serve as vehicles to deliver and combine parents' DNA
• The chromosome number is restored in the zygote after fertilization
• Human life stages


  • Infancy (0-2 years)
  • Childhood (1-12 years)
  • Adolescent (13-19 years)
  • Adulthood (20+ years)
• Infancy


  • Continuous physical development
• Childhood


  • Locomotor and cognitive skills development
• Adolescent


  • Undergoing various changes related to puberty
• Adulthood


  • Sexually mature physically and behaviorally
• Male reproductive anatomy


  • Testis
  • Scrotum
  • Epididymis
  • Urethra
  • Vas deferens
  • Seminal Vesicle
  • Prostate Gland
  • Bulbourethral Gland
  • Penis
• Testis


  Male gonad that produces and nourishes sperm cells
• Scrotum


  External sac that regulates temperature for testis
• Epididymis


  Stores sperm cells produced and transports them to vas deferens
• Urethra


  Common exit duct for both the urine and semen
• Vas deferens


  Pathway of sperms from testis to the urethra
• Seminal Vesicle


  Contributes alkaline fluid that nourishes and protects sperm cells
• Prostate Gland


  Contributes a fluid that neutralizes semen and vaginal fluid
• Bulbourethral Gland


  Contributes a fluid that functions for lubrication
• Penis


  Copulatory organ that conveys sperm to female reproductive tract
• Female reproductive anatomy


  • Ovary
  • Fallopian Tubes
  • Fimbriae
  • Uterus
  • Cervix
  • Vagina
  • External Genitalia
  • Bartholin's Gland
• Ovary


  Female gonad that produces and nourishes egg cells
• Fallopian Tubes


  Ducts that serve as fertilization site and leads to the uterus
• Fimbriae


  Appendages of the fallopian tubes that catch eggs during ovulation
• Uterus

  Highly vascularized sac that nourishes the developing embryo
• Cervix

  Narrow channel that prevents further entry of foreign materials
• Vagina

  Receives the sperm cells and serves as the birth canal
• External Genitalia

  Accessory structures of the female reproductive system
• Bartholin's Gland

  Produces fluid that serves as lubrication during intercourse
• Gametogenesis

  • Reduction of the chromosome number
  • Makes sperm cells sufficiently motile
  • Produces egg cells with enough nutrients
  • Spermatogenesis (♂) or oogenesis (♀)
• Spermatogenesis

  1. Occurs in the seminiferous tubules of male testis

  2. Nourishing cells include the sertoli cells

  3. Starts during puberty and continuous throughout life
• Spermatogenesis steps

  1. Proliferation

  2. Growth

  3. Maturation

  4. Differentiation

  
• Oogenesis

  1. It occurs in the ovaries and fallopian tubes

  2. The follicles of the ovary exert hormonal influence

  3. It starts during the pregnancy of the mother
• Oogenesis steps

  1. Proliferation

  2. Growth

  3. Maturation

  4. Differentiation
• The polar body is a small meiotic product of the unequal division in oogenesis in females. It allows to concentrate the cytoplasmic contents into one ovum.
• Human fertilization

  • Fusion of the gametes or sex cells from male and female parents
  • Sperm cell must pass through the granulosa and jelly coat layers
  • With slow-block and fast-block mechanisms against polyspermy
  • Produces the zygote with normal or restored chromosome number
• Placenta

  Structure during gestation that supplies the developing fetus with oxygen and nutrients from the mother, and removes the wastes accumulated by the fetus