Human Rep

• The reproductive system is not needed for keeping someone alive, but is essential to keeping the human population going
• Gender


  Female and male, made possible by genetics and reproductive hormones
• Sex chromosomes


  • Control how a developing fetus's reproductive organs form
  • XX in females, XY in males

  
• Reproductive hormones


  Chemicals that travel through the bloodstream and influence the reproductive organs
• Gametes


  Eggs (female) and sperm (male), special cells that hold genetic information needed to create a baby
• Gametes are a living link that sparks the next generation and keeps the human race going in an unbroken chain
• Puberty


  Period of time when the reproductive system becomes fully active for the first time, usually ages 12-14
• Changes during puberty


  • Boys develop into young men, girls develop into mature women
  • Hair, voice, muscle growth, etc.
• Sex steroids


  Hormones made by the ovaries and testes that stimulate the reproductive organs
• Physical changes during puberty


  • Hair under arms becomes coarse and visible
  • New kinds of sweat glands become active
  • Hair on arms and legs becomes more noticeable
  • Coarse hair appears around genitals
  • Reach adult height as bones go through final growth phase
• These outward changes are a clear sign that the reproductive system is maturing inside as well
• Ovaries


  Organs where eggs are made
• Follicles


  Eggs grouped with other cells that surround the egg
• Ovulation


  Follicle develops a tear on outer surface, fluid rushes out carrying the egg
• Corpus luteum


  Mass of cells left behind after egg is released
• Oviducts


  Tubes that connect ovaries to uterus, help move egg along
• Uterus


  Hollow, pear-shaped organ where fetus develops

  
• Endometrium


  Lining of uterus that egg brushes against
• Menstrual cycle


  Monthly changes in endometrium, from thin to thick and back to thin
• Vagina


  Stretchy tube connecting uterus to outside of body
• Female genitalia


  Reproductive organs visible in pubic area
• The brain is not usually listed as part of the reproductive system but is just as important
• Pituitary gland


  Makes hormones that control ovaries and testes
• Hypothalamus


  Brain region that controls pituitary gland and coordinates reproductive activities
• Reproductive hormones influence the brain, for example sexual desire becomes powerful at puberty
• id


  Cleanses and protects the vagina from infection, and also aids in sexual intercourse
• Female Genitalia


  Reproductive organs that are visible in the pubic area (between the legs)
• Parts of Female Genitalia


  • Labia minora
  • Labia majora
  • Clitoris
• Labia minora


  • Cover the opening to the vagina and urethra, help keep germs out
• Labia majora


  • Enclose the labia minora
• Clitoris


  • Pea-sized genital structure that gives pleasurable feelings during sexual activity
• Breasts


  Part of the female reproductive system, change and grow in response to sex steroids during puberty
• Breast development during puberty

  1. Fat collects in breasts

  2. Milk-producing glands form
• Testes


  Where male gametes (sperm) are made
• Testes


  • Held in a pouch of skin called the scrotum, located between and slightly in front of the legs
  • Must be a few degrees cooler than normal body temperature
• Descent of testes


  Testes of a fetus start out inside the body, gradually move into the scrotum in the last few months before birth
• Seminiferous tubules


  Tiny tubes in the interior of each testis where sperm are made
• Sperm production


  1. Spermatogonia make copies of themselves and develop into sperm after puberty

  2. Process continues for the rest of a man's life
• Sertoli cells


  • Deliver nutrients, energy, water, hormones and other materials to developing sperm
• Leydig cells


  Cells in the testis that make sex steroids, specifically the male hormone testosterone