Male reproductive organs

Question 1

78. Testis (HE)

Answer 1

• Tunica albuginea: dense fibrous tissue around testis + mediastinum testis
• septula testis⇒ 250 testicular lobes
• Tunica vasculosa: on inside of tunica albuginea
• 1 lobe ⇒ 1-4 convoluted seminiferous tubule
• seminiferous tubule ⇒ tubuli recti ⇒ rete testis ⇒ efferent tubule
• intertubular space: Leydig cells, fibroblast, mast cells, macrophages

Question 2

Seminiferous tubule

Answer 2

• epithelium: stratified seminiferous
• spermatogenic and non-spermatogenic supporting cells
• lamina propria: fibers + myoid cells (produce collagen)

Question 3

Leydig cells

Answer 3

• in interlobular space
• large, polyhedral or round
• produce testosterone
• large eccentric nucleus and 1-2 nucleoli
• cytoplasm is acidophilic but poorly stained
• absent in mediastinum

Question 4

Spermatogonia

Answer 4

• small diploid cells on basal membrane of seminiferous tubule
• Dark type: 12um, strongly basophilic, flattened ovoid nucleus, give rise to dark and pale type A spermatogonia
• Pale type A: light stained, ovoid nucleus, derivatives induced by testosterone ⇒ type B
• Type B: larger, pale, spheric nucleus, clumps of chromatin. undergo serial meiotic division

Question 5

Primary spermatocytes

Answer 5

• migrate to adluminal compartment
• large vesicle-like nuclei displaying chromosomes
• replicate DNA 2n⇒4n
• undergo 1st meiotic division

Question 6

Secondary spermatocytes

Answer 6

• much smaller cells
• diploid amount of DNA, haploid number of chromosomes
• short lived
• undergo second meiotc division

Question 7

Spermatids

Answer 7

• small 8um, round haploid cell

- undergo spermatogenesis-maturation to spermatozoa

Question 8

Sertoli cells

Answer 8

• tall columnar cells
• ovoid, euchromatic nucleus and prominent nucleolus
• located on basal lamina
• exhibit complex processes and invaginations
• desmosome-like junction with spermatogenic cells
• blood-testis barrier
• gives support and nutrition

Question 9

19. Epididymis (HE)

Answer 9

• head-body-tail
• 12-20 efferent ductules⇒ head of epididymis⇒ conical lobules ⇒ ductus epididymis
• epithelium of efferent ductule: ciliated tall columnar + short non-ciliated cells
• epithelium of ductus epididymis: tall columnar principal cells + short basal cells + stereo cilia

Question 10

90. Spermatic cord (HE)

Answer 10

• 3 coverings: external spermatic fascia, cremasteric fascia, internal spermatic fascia
• EPITHELIUM: simple columnar / pseudo stratified columnar
• LAMINA PROPRIA: elastic fibers
• MUSCULARIS EXTERNA: inner + outer longitudinal, middle circular
• processus vaginalis testis: betwen cremaster muscle + ductus deferens

Question 11

Spermatic cord components

Answer 11

• Composed of:
  
  • ductus deferes
  • testicular, deferential and cremasteric artery
  • palpiniform plexus
  • lymph vessels
  • genitofemoral n, testicular sympathetic plexus

Question 12

81. Prostate (HE)

Answer 12

• dense prostatic fascia + venous plexus
• fibromuscular stroma
• capsule: fibroelastic + septa ⇒ lobes
• Mucosal + submucosal glands: internal zone,pseudo stratified epithelium
• Main glands: peripheral zone, long and branched, simple columnar
• prostatic duct: stratified columnar epithelium, open into prostatic urethra
• pelvic diaphragm: striated muscles
• corpora amylacea: colloid amyloid bodies in alveolar lumina ⇒ concentric lamellae of calcified glycoprotein

Question 13

89. Seminal vesicle (HE)

Answer 13

• highly coiled tubular gland with irregular diverticula
• EPITHELIUM: pseudostratified cuboidal /simple columnar
• LAMINA PROPRIA:
  
  • cellular CT + smooth muscle
  • thin, long branching and interconnecting folds of mucosa ⇒ labyrinth-like appearance
• SUBMUCOSA: thin
• MUSCULARIS EXTERNA: inner circular, outer longitudinal
• ADVENTITIA: CT + elastic fibers

Question 14

Seminal vesicle cells

Answer 14

• Secretory products:
  
  • fructose
  • prostaglandins
  • endorphin
  • transferrin
  • lactoferrin
  • fibronectin
  • semenogelin, sperm motility inhibitor
• Functions:
  1. formation of sperm coagulum
  2. regulation of sperm motility
  3. suppression of immune function in female genital tract

Question 15

7. Penis (Verhoeff’s elastic stain)

Answer 15

• thin penile skin
• loose superficial penile fascia (no adipocytes)
• fascia penis: deeper, surrounds 3 cavernous bodies + separates superficial dorsal vein from deep dorsal vein , 2 dorsal arteries + nerves
• 2 corpora cavernosa penis + 1 corpus spongiosum penis (urethra)
• tunica albuginea: invests each corpora cavernosa penis + forms septum penis + traveculae ⇒ surround cavernous spaces
• Ebner’s cushions: semilunar protrusion in cavernous wall
• tunica albuginea of corpus spongiosum is thinner, more elastic fibers + smooth muscle

Question 16

Penile urethra

Answer 16

• epithelium: stratified columnar
• penile mucosa ⇒ many recesses
• Littre glands: in submucosa, mucus secreating

Question 17

Mechanism of penile erection

Answer 17

1. Sexual arousal ⇒ parasympathetic cholinergic activity ⇒ NO release ⇒ vasodilation in cavernosal and helical arteries ⇒ also relaxes smooth muscle in corpora cavernous + corpus spongiosum ⇒ rapid blood inflow ⇒ swelling
2. Widened cavernous spaces filled with blood ⇒ increasing pressure ⇒ compress venules ⇒ rigidity
3. NO release from endothelial cells ⇒ relax trabecular smooth muscle ⇒ more rigidity
4. Ejaculation by increasing sympathetic activity ⇒ contraction ⇒ vasoconstriction ⇒ decreased pressure ⇒ venules open ⇒ flaccid state