Male Reproductive

System

testes

ducts

accessory glands

• seminal vesicles
• prostate gland
• bulbourethral gland

penis

conveyance system for urine and semen

Testes

exocrine gland/organ

thick connective tissue layer

• tunica albuginea

tunica vascularis

tunica vaginalis

• remnant of descent of testes

subdivided into lobules

• approximately 250 pyramidally shaped compartments called lobuli testis
• each with 1 to 4 seminiferous tubules
  • about 70 centimeters long each and 150 to 250 micrometers diameter
  • exocrine portion
  • produce sperm
  • cells types
  • Sertoli cells
    • triangle shaped
    • supportive
    • wraps around to nourish developing sperm
  • spermatogenic cells
    • produce sperm
    • subtypes
    • spermatogonia
      • 2n
      • germ cells
      • closest to base
      • type a
      • continues as stem cells
      • type b
      • will become spermatid
      • as formed are pushed to center
    • spermatocytes
      • I are less mature
      • II are more mature
    • spermatid
      • spermatogenesis
      • the process of the cell developing through spermatocytes to spermatids
      • grow tail (flagellum)
      • removal of excess cytoplasm and organelles
    • spermatozoa
      • mature sperm
      • nucleus is haploid
      • acrosome in the head for fertilization
      • enzymes to burrow into egg
      • midpiece has lots of mitochondria and the microtubule core of flagellum
  • Cells of Leydig
    • source of testosterone
    • found in spaces between seminiferous tubules
    • spaces are called interstitial spaces
      • so could be called interstitial cells
    • also have macrophages and fibroblasts

Movement of sperm

seminiferous tubules

straight tubules

rete testis

canaliculi efferents

caput epididymis

Epididymis

highly coiled tube

4-7 cm

function

• storage
• capacitation
  • maturation of sperm into ability to fertilize

lumen full of spermatids

mucosa

• pseudostratified columnar epithelium with lots of stereocilia
• helps to provide nourishment
  • for capacitation
• relatively smooth with stereocilia

interstium

• smooth muscle
• for movement of sperm to next portion of duct system

Vas (Ductus) Deferens

structure similar to epididymis but without stereocilia

pseudostratified columnar epithelium

smooth muscle

• inner longitudinal
• middle circular
• outer longitudinal

ampulla

• swollen end portion
• where other contents are added
  • from seminal vesicles and prostate

Seminal Vesicles

highly folded

pseudostratified columnar epithelium

secretion

• high fructose
• molecular energy for sperm to convert to mechanical energy

Prostatic Urethra

where prostate adds its secretions

largest gland in male reproductive system

• size of small walnut

30-50 tubuloalveolar glands

• simple cuboidal to columnar epithelium
• contribute milky fluid
  • rich in zinc ion, citric acid, phosphatase, and proteolytic enzymes
  • pH 6.5-7.3
  • can crystalize with age, creating deposits in the lumen called corpora amylacea

Bulbourethral (Cowper’s) Gland

more mucus gland

nuclei near bottom of cell

secretion

• amino sugars
• sialoproteins
• for lubrication of pineal urethra to add in movement of semen

Semen

average amount is about 3 mL

100M sperm per mL

• about 20% is abnormal
• about 25% is immotile

includes the secretions from the 3 glands

Urethra

urothelium mucosa

erectile tissues

• corpora cavernosa (2)
  • found further from urethra
• corpus spongiosum
  • found surrounding urethra