I.Male Reproductive System

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I.Male Reproductive System

• Organs testes, ducts, glands supporting
  structures
• Supporting structures include scrotum penis
• Ducts epididymis, ductus deferens, ejaculatory
  ducts urethra
• Glands seminal vesicles, prostate, bulbourethral
  glands

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Figure 23.1
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A. Scrotum

• Pouch that supports the testes
• Septum separates into separate sections for each
  testis
• Sperm requires temperatures 2-3oC below body
  temperature
• allows raising and lowering testes to adjust
  temperature

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B. Testes

• Paired oval glands
• 200-300 lobules containing seminiferous tubules
• Sperm producing cells and nurse cells (protect
  sperm)

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C. Epididymis

• Stores sperm before ejaculation
• Comma shaped on top of testes

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Figure 23.2a
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Figure 23.2b
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D. Spermatogenesis

• Occurs in seminiferous tubules
• Cell types involved spermatagonia, sertoli cells
  interstitial cells (leydig cells)
• move into-gtepididymis

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Spermatogenesis stages

• Takes 65-75 days from first division to release
• 300 million /day
• Life span 48 hrs in female tract

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Figure 23.3
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E. Sperm

• Structure Head, middle, tail
• tail- flagellum motility
• Middle - mitochondria energy
• Head-chromosomes acrosomal cap
• acrosome-enzymes-gt penetrating egg

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Figure 23.4
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F. Sperm route

• Testes -gtEpididymis? vas (ductus) deferens
• ? urethra

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G. Semen

• 2.5-5 ml per ejaculation
• 50-150 million sperm per ml
• When number falls below 20 million/ml sterile
• 7.2-7.7 ph

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H. Accessory Glands

• Seminal vesicles- seminal fluid-
• Fructose (sperm ATP production
• alkalinity (neutralize acid in tracts)
• 60 of ejaculate

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• Prostate- surrounds upper urethra
• Increases volume adds antibiotics
• Citric acid for energy
• 25 of ejaculate
• Bulbourethral glands
• More alkalinity mucus fluid
• Pre ejaculate
• 10 of ejaculate

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I. Penis

• Contains urethra-
• Passage for semen urine
• Glans has external urethral oriface
• Uncircumcised glans covered by prepuce

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Figure 23.6
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II.Female Reproductive System

• Ovaries paired organs- produce
• secondary oocytes? ova (after fertilization)
• Hormones progesterone estrogens
• From same embryonic tissue as testes
• uterine (fallopian) tubes uterus
• vagina
• External organs (vulva or pudendum)

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A. Histological Structure of Ovary

• Germinal epithelium- covers surface
• Ovarian cortex connective tissue containing
  follicles
• Follicle oocyte surrounding cells
• Surrounding cells nourish oocyte produce
  hormones
• Grows during maturation ?
• Graafian follicle? ovulation
• Post ovulation ? corpus luteum?
• Progesterone, relaxin inhibin

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Figure 23.6
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Figure 23.7
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B. Uterine Tubes

• Two tubes- extend laterally from uterus
• End in fringe ? Fimbriae
• Fimbriae sweep secondary oocyte into tube
• Oocyte moved by cilia lining wall
• Zygote reaches uterus in 7 days

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C. Uterus

• Pathway for sperm site of implantation
• Fundus -Dome-shaped area above tubes
• Body tapering central portion
• Cervix- narrow opening into vagina
• Uterine cavity- interior of body

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Vagina

• extends from exterior to cervix
• Receptacles for penis and outlet for menstrual
  flow
• Fornix- recess surrounds cervix
• Acid environment- prevents bacterial growth
• Smooth muscular layer- adjusts for intercourse or
  birth
• Thin membrane fold can cover vaginal orifice
  hymen

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Figure 23.9
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Perineum vulva (cont.)

• Clitoris- small cylindrical mass of erectile
  tissue nerves
• Also contains prepuce glans
• External urethral oriface- anterior to vaginal
  oriface

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Female Reproductive Cycle

• 20-34 days- cycles in both ovaries uterus
• Ovarian cycle maturation of follicle, ovulation
  corpus luteum formation
• Uterine Cycle menstrual cycle
• controlled by hormones from ovary
• Estrogens? growth of endometrium Progesterone
  supports endometrium for implantation
• Combine cycles Reproductive cycle

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Figure 23.12
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Hormonal Regulation

• GnRH (hypothalamus) controls
• GnRH? FSH LH
• FSH? follicle growth estrogen secretion
• High estrogen ? LH surge ? ovulation
• LH supports corpus luteum ? progesterone
  estrogen secretion relaxin inhibin
• Inhibin ? decreased FSH release

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• Gonadotropin releasing hormone GnRH
• Comes from hypothalamus and stimulates the
  release of FSH from pituitary.

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Hormones

• FSH Follicle stimulating hormone
• Follicle stimulated to start maturing an egg
• Starts to rise at the end of the cycle and during
  menstruation. An egg starts to mature.
• Spikes during ovulation
• LH- Lutenizing hormone
• Peaks as estrogen peaks
• Helps to cause ovulation

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Hormones

• Estrogen
• Development maintenance of reproductive
  structures secondary characteristics
• Tells the uterine lining to build up
• From follicle
• Progesterone
• maintains uterine lining for implantation
• Prepares breast for milk production
• From corpus luteum

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• hCG- human chorionic gonadotropin
• Made by embryo
• Tells corpus luteum to keep making progesterone
  to maintain lining

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• Relaxin relaxes uterus- inhibits myometrium
• Inhibin- inhibits FSH release

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Phases of Cycle

• Menstrual phase 1st 5 days of cycle
• Several Ovarian follicles enlarge
• Decreased progesterone estrogen? uterine
  arteries constrict? endometrium sloughs off
• Preovulatory- between menstruation ovulation
• Ovaries follicles grow secrete estrogen
  inhibin? one dominates
• Uterus growth of new endometrium

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Phases of Cycle (cont.)

• Ovulation
• Release of 2o oocyte with LH surge
• Postovulatory-
• Ovaries follicle collapses? corpus luteum
  (luteal phase)
• If no fertilization? ? FSH LH ? corpus albicans
  decreased Progesterone ? menstruation

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Phases of Cycle (cont.)

• If fertilization division? human chorionic
  Gonadotrophin (hCG)? stimulates corpus luteum?
  secretion
• Uterus Progesterone estrogens? complete
  development of uterus for implantation

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Figure 23.13