Reproductive system

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Reproductive system
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Reproductive system

• Gametic meiosis
• All Animal Kingdom
• Gametes made by diploid organism directly by
  meiosis
• Syngamy makes zygote which develops into adult

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Fertilization

• External Eggs and sperm released outside of
  bodies of male/female
• Most marine bony fish most amphibians.

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Fertilization

• Internal Sperm deposited inside body of female
• Reptiles birds mammals

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Vertebrate Reproduction(Internal fertilization)

• Oviparity Eggs fertilized internally. Deposited
  outside mothers body to develop.
• Some cartilagenous fish some bony fish some
  amphibians most reptiles all birds few mammals
  (monotremes).

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Vertebrate Reproduction

• Ovoviviparity Eggs fertilized internally remain
  in mother. But rely on yolk for nourishment.
  Young developed and hatched when released.
• Some bony fish some cartilagenous fish some
  amphibians many reptiles

Salamandra female giving birth to larvae
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Vertebrate Reproduction

• Viviparity Young develop in mother and obtain
  nourishment mainly from mother (rather than
  ____________).
• Most cartilagenous fishes few bony fishes some
  amphibians few reptiles almost all mammals.

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Reproductive system

• Here we emphasize human system (rat seen in lab)
• Start with male move to female

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Reproductive system

• Male
• 1) Makes gametes (sperm) by meiosis
• 2) Delivers sperm to vagina in female system

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Reproductive system

• Sperm cell
• Flagellum to swim with
• Mitochondria for energy
• Nucleus (haploid) in head
• Acrosome special ____________ contains enzymes
  that help penetrate layers around egg.

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Reproductive system

• Male reproductive system
• 1) Testes (plural males have 2). Make sperm and
  androgens (male hormones such as testosterone)
• In bag called scrotum.

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Reproductive system

• 1) Testes Seminiferous tubules
• 1) germinal cells divide (mitosis) to produce
  primary spermatocyte
• 2) primary spermatocyte divides by meiosis to
  make 4 spermatids
• 3) Spermatids develop into sperm
• 4) Process aided by ______________ cells which
  help spermatids transform into sperm.

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Reproductive system

• Making sperm a fulltime job
• 100-200 million formed per day takes 100 days to
  make them
• Influenced by temperature
• Normal testis temperature is 34 degrees compared
  to 37 degrees internal body temperature.

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Reproductive system

• Male reproductive system
• 2) Ducts to carry sperm. Epididymis collecting
  duct at testis. Vas deferens duct from
  epididymis to seminal vesicle. Ejaculatory ducts
  from seminal vesicle to prostate gland.

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Reproductive system

• Male reproductive system
• 3) Accessory glands (package sperm). Seminal
  vesicles store sperm. Bulbourethral gland and
  prostate gland (produce ____________).

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Reproductive system

• Male reproductive system
• 3) Accessory glands (package sperm).
• Semen fluid that enhances longevity of sperm

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Reproductive system

• Semen fluid that enhances longevity of sperm
• Contains
• water
• sugars (fructose and glucose) used by sperm for
  energy
• __________________ neutralizes acidity from
  urine in male urethra and acidic conditions in
  vagina
• prostaglandins hormones that stimulate
  contractions of smooth muscle in female system
• vitamins minerals amino acids etc.

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Reproductive system

• Male reproductive system
• 4) Penis copulatory organ delivers sperm to
  __________ of female
• When male excited blood flow out decreased.
  Blood fills 2 corpora cavernosa (spongy tissue
  bodies on each side of penis) during erection.

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Reproductive system

• Female reproductive system
• 1) Produces gametes (eggs)
• actually oocytes cells ______________ to being
  eggs!
• 2) Also nourishes embryo during gestation period
  (time from fertilization to birth 9 months for
  human).

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Reproductive system

• Female reproductive system
• 1) Ovary (2 of them) Where oocytes formed
• 2) Fallopian tube (2 of them) connect ovary to
  uterus
• 3) Uterus where fertilized egg implants and
  embryo develops

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Reproductive system

• Female reproductive system
• 4) Cervix entrance to uterus
• 5) Vagina connects uterus to outside body

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Reproductive system

• Making oocytes in ovary
• Process starts before birth when germinal cells
  produce primary oocytes. These start meiosis I
  but stop at prophase I at time of birth as
  primary follicles.

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Reproductive system

• Follicles contain oocyte and cluster of other
  special cells
• Each female has about 2 ____________ follicles at
  birth.

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Reproductive system

• Once puberty begins one primary follicle matures
  each month during menstrual cycle.
• Maturation called ______________ ruptures
  follicle and releases secondary oocyte.

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Reproductive system

• In secondary oocyte meiosis I completed and
  meiosis II started. Stops at metaphase II.
• Will complete meiosis II to make egg only if
  fertilized by sperm!

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Reproductive system

• Note that follicle cells stay alive and secrete
  hormones for a time after secondary oocyte
  released
• Become corpus luteum.

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Reproductive system

• Hormones made by corpus luteum increase
  thickening of lining of uterus
• This readies uterus in case fertilization occurs
• Oocyte moves down Fallopian tube by _________
  lining tube.

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Reproductive system

• Menstrual cycle (takes about 28 days)

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Reproductive system

• 1) pituitary gland (in head under brain) secretes
  follicle stimulating hormone (FSH)
• 2) Follicles in ovaries begin to develop (only
  one continues to end)

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Reproductive system

• 3) Follicles release _____________ uterus lining
  starts to thicken

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Reproductive system

• 4) Estradiol stimulates more FSH. Also
  luteinizing hormone (LH) made by pituitary.
• 5) Peak of FSH and LH at day 14 causes ovulation
  release of secondary oocyte from 1 follicle.

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Reproductive system

• 6) Remnants of follicle are corpus luteum
• 7) Secretes estradiol and progesterone. They
  influence pituitary to decrease FSH and LH
  production. Follicles stop developing.

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Reproductive system

• 8) After several days corpus luteum starts to
  degenerate
• 9) Estradiol and progesterone levels drop

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Reproductive system

• 10) Uterine lining(endometrium) sloughs off
  (period starts)
• 11) Decrease in estradiol and progesterone cause
  pituitary to increase _______ production
• 12) Cycle starts again.

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Reproductive system

• If fertilization happens
• Embryo implants in uterine wall
• Eventually placenta takes over production of
  estradiol and progesterone. Lining stays
  thickened (no period). No more follicles develop.

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Reproductive system

• Lost along the way fertilized oocyte can get
  outside system and create ___________ pregnancy
  (implants in wrong places)
• Problem wont develop normally. Must be removed
  or can kill mother.

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Manipulating the system

• Birth control (or how not to make a baby)
• See also www.plannedparenthood.org

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Manipulating the system

• 1) Abstinence.
• Variation rhythm method. Time between _________
  release and arrival in uterus about 5 days (after
  ovulation). Sperm can remain alive in woman for
  several days.

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Manipulating the system

• 2) Sperm blockage (condom cervical cap or
  diaphagm)

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Manipulating the system

• 3) Sperm destruction
• washing sperm out (douche)
• spermicide foams/jellies

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Manipulating the system

• 4) Preventing ovulation the pill and implants of
  various types. Contain chemicals that act like
  ______________ (prevent follicle development).

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Manipulating the system

• 5) Preventing embryo implantation IUD
  (intrauterine device). Irritates uterine lining.

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Manipulating the system

• 6) Sterilization
• vasectomy for man (cutting/tying vas deferens)
• cutting/tying Fallopian tubes for woman.

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Manipulating the system

• Fertility clinics (how to make a baby)
• _______ of couples have difficulty conceiving a
  child
• About half cases due to male infertility other
  half female infertility

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Manipulating the system

• Male infertility
• Large numbers sperm needed due to barriers in
  journey
• 1) long distance (sperm swim 3 mm/hour)
• 2) acidic conditions in vagina
• 3) most are active for lt48 hours
• Typically many hundreds of millions deposited
  only few hundred reach fallopian tubes
• So numbers matter (Normal is____ million
  sperm/ml. Low is lt20 million/ml).
• Also vigor (activity level) and appearance
  (morphology) of sperm matter.

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Manipulating the system

• Fertility clinics (how to make a baby)
• Female infertility
• ______________ problems
• Anatomical problems

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Manipulating the system

• For both men and women age ___________ fertility