Reproduction

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Reproduction

• BIOL 242

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MALE sperm production

• Testes - paired oval glands 5 cm x 2.5 cm, 10 -
  15 g
• Function
• produce sperm
• produce androgens - testosterone
• tubes called seminiferous tubules which make
  sperm
• Start to descend in the 8th month of fetal
  development
• need cooler temperature to function
• Pathology
• cryptorchid
• may become cancerous
• cancer detect through self exam
• varicose veins

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MALE sperm production

• Scrotum
• loose skin and superficial fascia
• bag outside of body
• Epididymis
• coiled tube in the posterior testes - made up of
  a head, body, and tail
• Function - receive and matures sperm after they
  are formed
• large surface area and stores millions of sperm

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MALE sperm production

• Vas deferens - muscular (smooth) tube from testes
  to penis
• Function - sperm into pelvic cavity
• Ampulla - end
• Pathology
• vasectomy - separate tube from epididymis in
  scrotum

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MALE sperm production

• Penis
• male copulatory and urinary organ
• Function
• deposits sperm in vaginal fornix during
  ejaculation
• Parts 3 masses of cavernous or erectile tissue
  bodies
• Corpora cavernosa penile bodies - 2 fused
• ? crus that anchor into the bony ischiopubic rami
• skeletal muscle over crus ischiocavernosus
• Corpus spongiosum (cavernousus urethra) - 1 on
  bottom
• begins at proximally) and ends at the glans penis
  (distal)
• Urethra - ends in the glans and the external
  urethral orifice

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MALE sperm production

• Muscles
• Bulbocavernosus muscle
• covers the bulb of the corpus spongiosum
• function - contract to propel semen into urethra
• Ischiocavernosus muscle
• pulls the crura to maintain erection
• Both are skeletal muscle and are innervated by
  the pudendal nerve

1. Ureter2. Bladder 3. Vas deferens 4.
Prostate 5. Ureter muscle 6. Bulb of penis 7.
Ischiocavernosus muscle 8. Retractor muscle of
penis 9. Inside of prepuce 10. Elongated
portion of glans penis 11. External orifice of
urethra.
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• Glands - to produce fluid to join sperm, used for
  sperm motility survival once in female
• Seminal glands - posterior and inferior bladder
• lobulated exocrine gland also called seminal
  vesicles
• alkaline, viscous fluid
• sugar fructose (ATP), prostaglandins (motility
  and viability uterine contractions)
• fibrinogen (sperm coagulate temporarily in
  vagina)

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• Glands - to produce fluid to join sperm, used for
  sperm motility survival once in female
• Prostrate gland - inferior bladder at the apex,
  capsule around
• both ejaculatory ducts and urethra pass through
• made up of smaller glands venous plexus
• remains of the uterovaginal
• primordium from the indifferent stage of sexual
  development
• innervated by ANS to discharge prior to
  ejaculation and during ejaculation
• milky, slight acid
• citric acid,
• clotting enzymes (fibrogen activates to
  coagulate)
• Fibrinolysin - breaks up clot later in female
• antibacterial

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• Glands
• Bulbourethral glands - in the urogenital
  diaphragm
• produce mucus
• decrease leftover urine acidity
• discharge prior to ejaculation w/prostrate
  emission - no sperm present
• alkaline
• Stuff to know about Semen
• 3.5 ml semen w/100 million sperm per ml 350
  million sperm
• total of 20-120 million sperm infertile may
  be increased w/testosterone

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MALE sperm production

• Spermatic cord through inguinal canal into
  pelvis from testes
• connects testes to abdominal cavity where the
  testes initially develop
• pampiniform plexus - veins that drain into
  testicular vein ? L renal or IVC
• testicular a. - supplies testes and scrotum.
  Paired, off aorta ? inguinal canal
• cremaster m. - in the shape of loops, can raise
  the testes in the scrotum
• formed from the internal obliques during descent

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Spermatogonia (male gametocytes) or
spermatogenesis

• Spermatogonia (male gametocytes) or
  spermatogenesis
• takes 74d for spermatogenesis
• cells develop from primordial germ cell in the
  testes in embryo primordial germ cells
• ? spermatogonia but remain dormant until mitosis
  at puberty
• sperm production stimulated by FSH from pituitary

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• Spermatogonia 2n 46 chromos
• some remain as stem cells
• some differentiate
• ? primary spermatocytes 2n 23 pairs of
  chromosomes
• Under go meiosis ? to become spermatids
• Meiosis I -- secondary spermatocytes - 1n 23
  chromos
• crossing over and recombination
• each chromosome has 2 chromatids (2 copies of
  DNA) w/centromere
• Meiosis II -- spermatids - 1n
• remain connected by cytoplasmic bridge
• no cytokinesis
• In Seminiferous tubules of the testes
• Sustenacular cells (sertoli cells)- in the
  tubules also provide support nutrition
• blood testis barrier
• Interstitial endocrinocytes (cells of leydig)
• secrete Testosterone
• Now migrate through efferent ductules --
  epididymis

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• Hormonal Control
• LH - stimulates Interstitial cells of Leydig to
  produce testosterone for spermatogenesis
• release controlled by GnRH - gonadotropin
  release hormone
• starts at puberty
• FSH - stimulates sertoli cells for
  spermatogenesis
• release controlled by GnRH - gonadotropin
  release hormone
• GH - aids spermatogenesis
• Testosterone - made in the Interstitial cells of
  Leydig between the seminiferous tubules
• made from cholesterol
• also stimulated by gonadotrophic hormone ICSH -
  interstitial cell stimulating hormone

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• Clinical
• Infertility - low sperm count
• causes vary - state of health important
• Orchitis - inflammation of testes
• as in mumps (virus) in men - may destroy
  testes
• Vasectomy - BOTH vas deferens are cut and tied
• Varicocele - varicose veins in the pampiniform
  plexus (near testes)
• Prostrate cancer
• varies - may be lethal or grow slowly
• prostrate enlarges - blocks flow of urine and may
  cause bladder infection

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FEMALE

• External parts
• Perineum pudendum or vulva - upper thighs and
  between pubis symphysis and coccyx
• contains external parts
• 2 parts - 2 triangles
• urogenital and anal triangles
• Urogenital triangle - labia, clitoris, vestibule,
  vagina, and urethral orifices
• urogenital diaphragm floor of triangle, between
  ishiopubic rami
• sphincter urethra - voluntary skeletal muscle
  controls urination
• anal triangle

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FEMALE

• Mons pubis - large fold of skin w/pubic hair
• Labia majora - 2 large lips filled w/fat w/pubic
  hair
• Labia minora - smaller pinkish folds surrounding
  openings of the vestibule
• Vestibule - space between labia minora, opening
  for vagina and urethra
• Clitoris - mass of erectile tissue lying above
  vestibule
• covered by a prepuce
• has a glans, body and crus - very small
• Greater vestibular glands - secrete mucus and
  fluids into vestibule
• clinical - prone to formation of cysts and
  easily infected

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FEMALE

• Muscles
• Bulbocavernosus - surrounds vestibular folds
• cover vestibular bulbs - masses of erectile
  tissue along sides of the vestibule
• Ischiocavernosus - thin muscle over crura of
  clitoris

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Female

• Pelvic cavity organs
• Ovaries - paired about 1" large
• lie in ovarian fossa
• not covered by peritoneum
• suspensory ligaments hold up
• function - oogenesis - prod of eggs or ova,
• 13 yrs ? menopause 50 yrs
• production of estrogen and progesterone
• layers
• Germinal epithelium - outer layer,
• Tunica albuginea - dense irregular CT
• Stroma - contain ovarian follicles
• Ovarian Follicles - oocytes (immature ova)
• Corpus Luteum - mature vesicular follicle that
  has ruptured
• to expel secondary oocyte
• produces progesterone, estrogens, relaxin,
  inhibin
• until degenerates into fibrous tissue - corpus
  albicans

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Female

• Uterine Tubes
• Fimbriae w/cilia to capture egg
• Made of ostium, infundibulim and ampulla (where
  fertilization occurs)
• tube lined w/cilia and smooth m. to move ovum or
  zygote along
• Tubal ligation disconnect tubes to prevent
  pregnancy

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Female

• Uterus 3 layers
• serosa - parametrium
• connected to body wall by broad ligament,
  w/uterine a's and v's
• myometrium - 3 layers of smooth m.
• contract during parturition because of Ozytocin
  from pars distalis
• may be given to induce labor
• endometrium - surface simple columnar
• uterine glands
• CT
• functional layer shed - basal layer
  permanent or zygote implants
• Fundus -
• Body -
• Cervix
• tip of uterus extending into vagina
• common site for primary cancer
• detect w/PAP smear
• fitted w/diaphragm for birth control
• external os
• opening into vagina from uterus

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Female

• Vagina - copulatory passageway
• from cervix ? orifice in vestibule
• 90 degree angle to uterus
• 5-6 inches long
• very dispensable for fetus to pass
• urethra passes along anterior wall
• Fornices - spaces around cervix
• Hymen - membrane surrounding vaginal opening
• Vaginal orifice
• may be cut during parturition episiotomy
• Rugae - transverse folds

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Female

• Clinical
• Endometriosus - endometrium breaks off and passes
  retrograde into lateral walls of
• pelvic cavity to form black nodules - may damage
  other tissues
• IUD's may cause pelvic inflammatory disease -
  infection
• Prolapsed uterus - loss of support and migrates
  out ? vagina, usually from long labor
• Ovarian cysts - common in ovaries, large soft
  masses
• Fibroid Tumors - hard, large muscular tumors in
  the uterus, may be multiple
• Stenotic uterine tubes - narrow tubes may prevent
  conception - use balloons - enlarge
• Hysterectomy - removal of the uterus due to
  endometriosis, PID, cysts, cancer...

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Female

• Egg Development
• oogonia (2n) - early fetal development
• lie in collections called nests
• divide mitotically and produce more
• In ovaries lifetime 400 eggs one/28 day
  cycle
• born w/all potential ova will ever have
• from primordial germ cells
• By end of fetal development all are -- Primary
  oocytes 2n 2 million at birth
• enter prophase of Meiosis I but do not end
  meiosis I until puberty
• Second meiotic division is at fertilization
• surrounded by a follicle primordial
  follicles 200,000 in each ovary

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Female

• Puberty -
• primordial follicles - due to increase in FSH
• ? primary follicles
• surrounded by single cuboidal cells
• most degenerate - only 30 - 40 thousand primary
  oocytes remain
• Follicular cells - develop into Thecal cells
• make Estrogen and Progesterone
• LH - primary follicles
• ? meiosis resumes growing follicle
• finishes reduction division ? 1n
• First polar body packet of discarded nuclear
  material 1n
• Secondary oocyte - most of the cytoplasm
• surround granulosa cells
• cuboidal and columnar epithelium secondary
  (growing) follicle
• secondary (growing) follicle ? metaphase of
  meiosis II

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Female

• Ovulation
• Secondary oocyte and First polar body
• discharged w/supporting cells
• begins to bulge out the side of the ovary just
  prior to ovulation
• LH and FSH cause release of ovum 12-16 d into
  cycle
• released into body cavity
• caught by Fimbriae (w/infundibulum to catch)
• ? Uterine/Fallopian tube

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female

• IF sperm present
• ? rest of meiosis II and then fertilization
• Follicle cells in ovum ? after ovulation form
• corpus luteum - remains functional for about 2
  weeks
• produces Progesterone and Estrogen to aid in full
  development of the endometrium of uterus
• no fertilization
• ? regress cease hormone production
• ? corpus albicans - scar tissue
• fertilization
• ? remains functional for about 5-6 months
  producing hormones
• after 6 mo - placenta makes hormones

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• Hormonal Control
• FSH - from anterior pituitary
• initial development of ovarian follicles
• Estrogen - secreted by follicles, stimulated by
  FSH
• development and maintenance of female repro
  structures
• fluid and electrolyte balance
• increase protein anabolism - like GH
• LH
• further follicle development, ovulation,
  production of estrogens, progesterones, inhibin,
  and relaxin (delivery)
• Progesterone-w/Estrogen
• prepares endometrium for implantation and mammary
  glands for milk secretion
• Inhibin - from the corpus luteum of ovary
• inhibits secretion of FSH and GnRH
• Relaxin - from the corpus luteum of ovary and
  placenta
• relax pubic symphysis and dilate uterine cervix
  in last trimester

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• Birth control
• levels of Estrogen and/or Progesterone high
  enough to limit FSH and LH
• Pregnancy
• Placenta
• Starts to form - day 7 from fetal and maternal
  tissues
• estrogen and progesterone stimulate development
• Fetal membranes
• Yolk sac
• Allantois