The Female Reproductive System - PowerPoint by wanghonghx

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									The Female Reproductive
       System
   Created By: Taira Lynch
    Batesville High School
        Batesville, IN
            Organs of the Female
•   Organs
            Reproductive System
     – Primary sex organs (gonads)
         • Two ovaries
                – Produce eggs (sex
                  cells) and also
                  produce hormones
     – External and Internal
       accessory organs (get to
       later)                                 QuickTime™ and a
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•   Organ Functions                     are neede d to se e this picture.

     – Produce and maintain the
       female sex cells (egg cells or
       ova)
     – Transport the eggs to the site
       of fertilization
     – Provide a favorable
       environment for a developing
       baby
     – Produce female sex
       hormones
              The Ovaries
• Number/Size/Shape
   – There are two
   – Oval shaped
   – 3.5 cm long/2cm
     wide/1cm thick            QuickTime™ an d a
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• Function
   – Produce egg cells
     and hormones
                          The Ovaries
•   In the Womb
     – Baby forms several million
         primordial follicles
           • Inside every primordial
               follicle is a primary
               oocyte (egg cells that
               haven’t went through
               the meiosis process)
                                                QuickTime™ an d a
     – During fetus development,                   decompressor
         the number of primordial         are need ed to see this p icture .
         follicles start to decline due
         to degeneration; by the time
         the baby is born, only
         around a million remain.
•   Puberty
     – Only 400,000 primordial
         follicles left
     – She will release 400-500
         oocytes (egg cells) during
         her reproductive lifetime.
     The Female Reproductive System
        Internal Accessory Organs

• Internal Accessory
  Organs
   – Pair of uterine
     tubes (fallopian         QuickTime™ and a
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     tubes)
   – Uterus
   – Vagina
       The Uterine Tubes (Fallopian Tubes)
•   The Uterine Tubes
     – connect the uterus to each
       ovary
     – funnel shaped and open
       near the ovaries with
       attached tiny projections
       called fimbriae
     – Most fimbriae do not touch
       the ovary, but one of the
       larger extensions connect             QuickTime™ and a
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       directly to the ovary.          are neede d to se e this picture.
     – The inside of the uterine
       tubes are lined with ciliated
       epithelial cells that help to
       guide the secondary oocyte
       toward the uterus via the
       sweeping action of the cilia
       and peristaltic contractions
       of the uterine tube’s
       muscular layer.
                        The Uterus
•   The Uterus
     – If the secondary oocyte is
       fertilized in the uterine
       tube, the uterus receives
       the embryo and sustains
       it.
     – A hollow, muscular organ
       shaped like a light bulb           QuickTime™ and a
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     – In its non-pregnant state,   are neede d to se e this picture.

       the uterus is small.
          • 7cm long/5cm wide,
            2.5 cm in diameter
     – Upper part is larger than
       the bottom
     – Uterine tubes are
       continuous with upper part
                             The Uterus
•   The Uterus
     – Lower third is called the cervix
        (socket of the light bulb)
          • The tubular part of the
            uterus                               QuickTime™ and a
          • It surrounds the opening               decompressor
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            called the cervical orifice,
            through which the uterus
            opens to the vagina.
     – Uterine wall made up of three
        layers:
          • Endometrium
                – Inner most layer
          • Myometrium
                – Middle, muscular
                  layer
          • Perimetrium
                                                 QuickTime™ and a
                – Outer serosal layer              decompressor
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                  that covers the body
                  of the uterus and part
                  of the cervix
              The Pap Smear
• The Pap Smear
   – A procedure in
     which a doctor or
     nurse scrapes off a
     tiny sample of
     cervical tissue,
     smears the sample               QuickTime™ and a
     on a glass slide,                 decompressor
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     stains it, and studies
     it for the presence
     of abnormal cancer
     cells.
             The Vagina
• The Vagina
  – Located behind
    the bladder and
    urethra (tube
                             QuickTime™ and a

    that conveys               decompressor
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    urine) and in
    front of the
    rectum/anus.
      The Female Reproductive System
             External Organs
• The External Organs
   – Labia majora
   – Labia minora
   – Clitoris                   QuickTime™ and a
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   – Vestibular glands    are needed to see this picture.


• These structures
  surround the openings
  of the urethra and
  vagina and compose
  the vulva.
   Hormonal Control of the Female
 Reproductive System and Oogenesis
• The hypothalamus (in the
  brain), anterior pituitary gland,
  and the ovaries secrete
  hormones. These hormomes
  control:
                                             QuickTime™ and a
   – development and                          decompressor
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     maintenance of female
     secondary sex
     characteristics
   – Maturation of the female
     sex cells
   – Changes during the
     monthly reproductive cycle
   Hormonal Control of the Female
 Reproductive System and Oogenesis
• The Menstrual Cycle
   – The hypothalamus begins to secrete increasing
     amounts of GnRH (gonodotropin releasing
     hormone) in response to low estrogen levels.
   – GnRH triggers the anterior pituitary gland to
     secrete increased amounts of FSH (follicle
     stimulating hormone) and to store LH (luteinizing
     hormone).
   – FSH triggers 20 or so primordial follicles to swell
     up and turn into primary follicles, with one
     eventually outgrowing all others.
   – These “swelling” primary follicles release
     increasing amounts of estrogen and progesterone.
     These hormones cause the endometrium of the
     uterus to thicken.
   Hormonal Control of the Female
 Reproductive System and Oogenesis
• The Menstrual Cycle
   – Inside each primary follicle, there is a primary oocyte.
   – The primary oocyte, inside of the follicle, completes the
     first division of meiosis turning into a secondary oocyte
     (23X’s/46chromosomes) and a 1st polar body
     (23X’s/46chromosomes).
   – The larger secondary oocyte is destined to fuse with the
     sperm; the smaller 1st polar body will eventually degrade.
   – Around day 14 of a woman’s 28 day cycle, the anterior
     pituitary secretes the stored LH (luteinizing hormone).
   – The surge of LH from the anterior pituitary causes one of the
     twenty primary follicles to swell rapidly and its walls to
     weaken.
   – Eventually, the wall ruptures, and the secondary oocyte and
     the 1st polar body, along with supporting cells, bursts through
     the ovarian wall. This is called ovulation.
   Hormonal Control of the Female
 Reproductive System and Oogenesis
• The Menstrual Cycle
   – The primary follicle stays behind and becomes a structure
     called the corpus luteum.
   – The corpus luteum secretes even more progesterone and
     estrogen which further encourages the endometrium layer to
     thicken. However, the high levels of estrogen and
     progesterone shut down the brain’s release of GnRH which in
     turn, shuts down the release of the gonodotropins (FSH and
     LH)
   – The secondary oocyte is guided into the fallopian tube with
     the help of the fimbriae.
   – If the secondary oocyte is fertilized, the secondary oocyte will
     divide unequally once again into an egg nucleus and a 2nd
     polar body. The egg nucleus will then fuse with the sperm
     nucleus becoming the first cell, a zygote. The second polar
     body will disintegrate.
   – If the secondary oocyte is not fertilized, then in a relatively
     short time, it degenerates.
   Hormonal Control of the Female
 Reproductive System and Oogenesis
• The Menstrual Cycle
   – In addition, the corpus luteum breaks down on about the
     24th day of the cycle if the secondary oocyte is not
     fertilized.
   – When it breaks down, estrogen and progesterone levels
     plummet causing blood vessels in the uterus to constrict
     thus reducing the supply of oxygen and nutrients to the
     endometrium lining…it dies.
   – The tissue disintegrates and sloughs off damaging
     capillaries and creating a flow of blood and cellular debris
     (menstrual flow).
   – Flow begins on about the 28th day of the cycle and lasts
     while estrogen levels are low.
   – The low estrogen levels at this time triggers the
     hypothalamus to kick back on again, causing the cycle to
     repeat again.
                        The Hormones
•   Estrogen’s Role
     – responsible for causing the
        enlargement of accessory
        organs
          • vagina, uterus, uterine
            tubes, ovaries, and
            external reproductive
            organs
     – develops and maintains the
        female secondary sex
        characteristics which include:
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          • breast development and                 decompressor
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            the ductile system of the
            mammary glands within the
            breasts
          • increased deposition of
            adipose (fat) tissue in the
            breasts, thighs, and
            buttocks
          • increased vascularization
            of the skin.
     – Maintains blood flow to
        endometrium lining when levels
        are high
                  The Hormones
• Progesterone’s Role
   – Maintains blood flow to
     endometrium
• Androgens’ Role
   – Causes increased hair
     growth in pubic and
     armpit regions                  QuickTime™ and a
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   – Lack of androgens are
     responsible for a more
     petite skeleton with
     narrow shoulders and
     wider hips.
                                Menopause
•   After puberty, menstrual cycles
    continue at reg. intervals into the late
    forties or early fifties, when they
    become increasingly irregular.
•   Menopause
      – Cessation of period
•   Causes of Menopause
      – Aging of the ovaries
            • After about 35 years of
               cycling, few primary follicles
               remain for pituitary
               gonadotropins to stimulate.
               Consequently, the follicles no         QuickTime™ and a
               longer mature, ovulation                 decompressor
               does not occur, and blood        are neede d to see this picture.
               estrogen levels plummet.
•   Reduced Estrogen and Progesterone
      – May change the female sec.
          sexual characteristics
            • Breasts, vagina, uterus, and
               uterine tubes may shrink
            • Pubic and armpit hair may
               thin
         Birth Control verses
            Contraception
• Birth control
   – an attempt to regulate the amount of offspring
     conceived and when they are conceived
   – requires the use of contraception
       • Contraception works by avoiding fertilization
         of an egg cell following intercourse or
         preventing the blastocyst from implanting in
         the uterine wall.
        Coitus Interruptus and Rhythm
                    Method
•   Coitus Interruptus
     – withdrawing penis from vagina
         before ejaculation
     – Poor type of contraception
         because small quantities of
         sperm may enter vagina prior to
         ejaculation or the male may fail to
         withdraw at the correct time
•   Rhthym Method                                       QuickTime™ and a
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     – requires abstinence from
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         intercourse a            few days
         before and a few days after
         ovulation (when the female is
         most fertile)
     – This type of birth control results in
         many pregnancies due to the
         couples failure to correctly identify
         ovulation times.
     – Most often used as a method to
         GET pregnant.
                                  Mechanical Barriers
•   Mechanical Barriers
     – prevent sperm cells from entering the
        female reproductive tract during
        intercourse
           • male condom
                  – thin latex or natural
                      membrane sheath placed                       QuickTime™ and a
                      over penis prior to intercourse                decompressor
           • female condom                                   are needed to see this picture.
                  – resembles a small plastic
                      bag. A woman inserts this
                      into her vagina prior to
                      intercourse (opened end on
                      the outside if body)
           • Diaphragm
                  – cup-shaped device with a
                      flexible ring forming the rim. A
                      woman inserts this into
                      vagina so that it covers the
                      cervix. Most effective if used
                      together with spermicide
                      (sperm killer). It must also
                      remain in position for several            QuickTime™ an d a
                      hours following intercourse.                 decompres sor
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           • cervical cap
                  – smaller than diaphragm,
                      adheres to the cervix by
                      suction.
                   Chemical Barriers
• Chemical Barriers
   – include creams,
     foams, and jellies
     that kill sperm within         QuickTime™ an d a
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     the vagina               are need ed to see this p icture .

   – high failure rate
     when used alone
   – more effective when
     used along with
     mechanical barriers
              Oral Contraception
• Referred to as “the pill”
• contains synthetic
  estrogen-like and
  progesterone-like
  chemicals
• These fake hormones
  prevent the hypothalamus
  and anterior pituitary from
  releasing FSH and LH (low           QuickTime™ and a
  levels of estrogen and                 decompressor
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  progesterone cause the
  gonadotropins to be
  released). As a result,
  primary follicles never
  mature and ovulation never
  occurs.They also interfere
  with buildup of the uterine
  lining.
              Oral Contraception
• Oral contraception is
  highly successful. If taken
  properly, they prevent
  pregnancy nearly 100% of
  the time.
• Side effects include:
   – Nausea
   – water retention
                                      QuickTime™ and a
   – increased skin                     decompressor
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     pigmentation
   – breast tenderness
   – intravascular blood
     clots
   – liver disorders
   – high blood pressure
            Injectable Contraception and
               Contraceptive Implants
• Injectable
  Contraception
   – a shot that prevents the
     maturation and release of
     a secondary oocyte for
     three months after the            QuickTime™ and a
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     injection                   are neede d to see this picture.


• Contraceptive Implants
   – small capsules or rods
     that are inserted
     surgically under the skin
     of a woman’s arm or
     scapula region
   – prevents ovulation for up
     to five years
       Intrauterine Device (IUD)
• a small, solid object that
  a doctor places within
  the uterine cavity
• prevents the blastocyst
  (early embryo) from                QuickTime™ and a
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  attaching itself to the
  uterine wall
• may produce abdominal
  pain or excessive
  menstrual bleeding
• Controversial?
       Tubal Ligation (Surgical Methods)
•   surgical methods sterilize the
    male or female
•   Vasectomy
     – performed on male
     – a small section of each vas            QuickTime™ and a
        deferen is cut and tied thus            decompressor
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        preventing sperm from
        traveling out of the body
     – sperm are still produced, but
        they disintegrate in each
        epididymis
     – simple operation and
        causes little pain for the
        man
     – does not have any
        significant effect on
        ejaculation because sperm
        account for only 1 percent of
        the total volume of semen
     Tubal Ligation (Surgical Methods)
• Tubal Ligation
   – performed on female
   – the uterine tubes are
      cut and tied so that
      sperm can’t reach the         QuickTime™ and a
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      eggs                    are neede d to se e this picture.



• neither tubal ligation
  procedure changes
  hormonal levels or
  interferes with sexual
  drive (libido)
• most reliable forms of
  contraception besides
  abstaining from sex

								
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