Science

• Female Reproductive System


  • Fallopian tube
  • Ovary
  • Uterus
  • Cervix
  • Vagina
  • Endometrium
  • Labium majora
  • Labium minera
  • Clitoris
  • Bladder
  • Pubic bone
• Fallopian tube


  Transports the egg to the site of fertilization
• Ovary


  Produces the female egg necessary for reproduction
• Uterus


  Offers a safe and favourable environment for a baby to develop before birth
• Cervix


  Allows sperm to enter and menstrual blood to exit
• Vagina


  Where the penis is inserted during intercourse, widens during birth to allow an infant to pass out of the body
• Endometrium


  Grows to a thick, blood-vessel lining for the uterus during the menstrual cycle, acts as a bed for the embryo during pregnancy
• Labia majora


  Enclose and protect the other external reproductive organs, comparable to the scrotum in males
• Labia minora


  Lie just inside the labia majora and surround the opening to the vagina
• Clitoris


  A small, sensitive protrusion comparable to the head of the penis in males
• The function of the external female reproductive structures (the genitalia) is to enable sperm to enter the body and to protect the internal genital organs from infectious organisms
• Major female reproductive hormones

  • Follicle stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Estrogen
  • Progesterone
• FSH


  Stimulates the development of female sex organs and follicle development within the ovaries
• LH

  Triggers ovulation
• Estrogen


  Plays a role in ovulation and thickens the lining of the uterus to prepare it for pregnancy
• Progesterone


  Prepares the endometrium for the potential of pregnancy after ovulation, prohibits the muscle contractions in the uterus that would cause the body to reject an egg
• Puberty begins when the hypothalamus triggers the release of GnRH and FSH from the pituitary in females
• Menopause is when the body stops producing the same hormones and a female generally stops having her period, typically happening in a woman's 50s-60s
• Phases of the menstrual cycle

  • Flow phase (days 0-7)
  • Follicular phase (days 7-14)
  • Ovulatory phase (day 14)
  • Luteal phase (days 14-28)
• Flow phase


  Marks the beginning of the cycle, characterized by shedding of the endometrium, hormone levels are at their lowest
• Follicular phase


  FSH stimulates the maturation of a follicle, estrogen is secreted promoting endometrial development
• Ovulatory phase


  Estrogen triggers a sharp increase in LH production, signaling the release of the mature ovum from the follicle
• Luteal phase


  The corpus luteum forms and secretes estrogen and progesterone, preparing the uterus for a potential pregnancy
• Genes


  Sections of chromosomes, or strands of DNA that code for different traits
• At birth, a woman has approximately 1 million eggs, by puberty only about 300,000 remain, and 300-400 will be ovulated during her reproductive lifetime
• Heritable traits


  Variations that are passed down from parents to offspring
• The vast majority of the eggs within the ovaries steadily die, until they are depleted at menopause
• Continuous variation


  Variations that have a range of possibilities
• Discrete variation


  Variations that have limited possibilities (either/or)
• DNA


  Deoxyribonucleic acid
• Alleles


  Possible forms of a gene
• Dominant allele


  Only one allele is needed to show the trait
• Recessive allele


  Two alleles needed to show the trait
• Genotype


  Which alleles you have
• Phenotype


  Which trait you express
• Heritable traits


  • Eye colour
  • Hair colour
  • Ability to roll tongue
• Humans have 46 chromosomes in total, or 23 pairs. You inherit one copy of each chromosome from each of your parents, meaning that 50% of your DNA comes from your mom, and 50% comes from your dad.
• Karyotype


  46,XX or 46,XY
• Karyotype variations


  • Turner Syndrome 45,X
  • Down Syndrome 47,XX+21 or 47,XY+21
• Allele


  Possible forms of a gene