Histology of Male repro tract

Question 1

Excurrent duct system

Answer 1

• Epididymis
• Vas deferens
• Ejaculatory duct
• Urethra

Question 2

Male accessory glands

Answer 2

• Seminal vesicle
• Prostate gland
• Bulbourethral glands

Question 3

Gross structure of testis

Answer 3

Tunica vaginalis
Tunica albuginea
Tunica vasculosa
Septa
Mediastinum

Question 4

Tunica vaginalis

Answer 4

• An extension of the abdominal peritoneum

* Covers anterolateral surface

Question 5

Tunica albuginea

Answer 5

• Dense outer CT capsule

Question 6

Septa of testis

Answer 6

• Projections of capsule

* Divide testis into lobules of one to four seminiferous tubules

Question 7

Mediastinum of testis

Answer 7

• Thickening of the tunica albuginea

• Contains the rete testis
o An anastomosing channel system collecting the products of the seminiferous tubules

• These structures not visible in all whole mount sections

Question 8

Seminiferous tubules

Answer 8

site of spermatogenesis
3 distinct regions:
- seminiferous epithelium, (sertoli cells, spermatogenic cells)
- tunica propria (or lamina) (myoid cells)
Interstitium (leydig cells)

Question 9

Sertoli cells

Answer 9

• Supportive cells

• Predominant before puberty, 10% after puberty
o Post-mitotic after puberty

• Columnar

• Extensive apical and lateral processes
o Provide crypts for developing spermatogenic cells

• Extend full thickness of epithelium

• Blood-testis barrier
o Basolateral occluding junctions between adjacent sertoli cells

Question 10

Spermatogenic cells

Answer 10

Replicate and differentiate into mature sperm
Poorly defined layers
o	Most immature at the basal lamina
	Spermatogonia
o	Most mature at the lumen
	Spermatids and spermatozoa

At the basal lamina
o	Type A Spermatogonium (SA)
	Large round or oval nucleus
o	Type B Spermatogium (SB)
	Dispersed chromatin with prominent nucleolus
In the adluminal compartment
o	Primary spermatocyte (S1)
	Large nucleus with clumps or threads of chromatin
	Copius cytoplasm
o	Secondary spermatocyte (S2)
	Rapidly dividing therefore not see

Near the lumen
o	Spermatid (S3)
	Dense, round nucleus
o	Spermatozoon (S4)
	Dense, pointed nucleus

Sertoli cell (St)
o	Triangular or ovoid nucleus with prominent nucleolus and dispersed chromatin, always in contact with basal lamina

Question 11

Spermatogenesis review

Answer 11

Spermatogonial phase
 Undergo mitosis
 Replenish germ cell population (Type A)
 Create committed spermatogonia that will differentiate (Type B)
o Spermatocyte phase
 Undergo meiosis
 Primary spermatocytes (4n) undergo first meiotic division
 Secondary spermatocytes (2n) undergo second meiotic division
 Create spermatids (1n)
o Spermatid phase
 Undergo spermiogenesis
 No further division, just maturation
 Extensive cell remodeling to mature spermatozoa

Question 12

Tunica propria (or lamina)

Answer 12

o	At the basal lamina
o	Myoid (peritubular) cells
- Collagen secreting
-Contractile to promote peristalsis
•	Sperm non-motile at this point
o	Thickens with aging, associated with infertility

Question 13

Interstitium

Answer 13

Vasculature, lymphatics, macrophages and

Leydig cells
	Androgen-producing
•	Primarily testosterone
•	Normally, resembling fibroblasts and inactive from birth to puberty
	Polygonal, eosinophilic
	Abundant sER
	Contain lipid droplets
	Sometimes present in cytoplasm:

Lipofuscin
Crystals of Reinke
o Rod-shaped cytoplasmic protein deposits
o Unknown function

Question 14

Intratesticular Ducts

Answer 14

Straight tubules (tubuli recti)
•	Short ,terminal portion of seminiferous tubules
•	Sertoli cells only transitioning into cuboidal epithelium

Rete testis
• Anastomosing channels
• Simple cuboidal or low columnar epithelium
• Apical cilia and microvilli

Question 15

Excurrent duct system: Efferent ductules

Answer 15

 Drain rete testes into epididymis
 Transitional but similar to epididymal epithelium and smooth muscle

(not the same as transitional epithelium re: urinary)

Question 16

Excurrent duct system: Epididymis

Answer 16

Long, convoluted duct
Function is to accumulate and store spermatozoa for maturation (will see these)
Consists of:
• Smooth muscle
o Increases from one to three layers as it moves distally

• Pseudostratified columnar epithelium
o Prinicipal cells
 Decrease in height as it moves distally
 Contain stereocilia

• Long microvilli
o Basal cells
 Small, round stem cells at basal lamina

Question 17

Excurrent duct system: Vas deferens (ductus deferens)

Answer 17

Conducts spermatozoa from epididymis to urethra
Thick walled muscular tube
Consists of
•	Smooth muscle 
o	Inner and outer longitudinal layers
o	Intermediate circular layer
•	Pseudostratified columnar epithelium	
o	Closely resemble epididymis
o	Contains longitudinal folds for expansion

Question 18

Excurrent duct system: Ejaculatory duct

Answer 18

 Convergence of the vas deferens and duct of the seminal vesicle
 Travels through prostate
 Transitional but similar to vas deferens epithelium and smooth muscle

Question 19

accessory glands: Seminal vesicle

Answer 19

Paired, highly folded tubular glands
Secrete 85% of seminal fluid volume
• Fructose, other simple sugars, amino acids and prostaglandins

Consists of:
•	Smooth muscle
o	Both circular and longitudinal
•	Mucosa
o	Numerous folds
o	Pseudostratified columnar epithelium: Non-ciliated columnar cells--Large secretory vacuoles, and Round cells that rest on basal lamina
•	Fibrous coat

Question 20

Prostate gland

Answer 20

Secrete alkaline fluid that contributes the other 15% of seminal fluid volume
30+ tubuloalveolar glands
- Glands
o Glandular epithelium
 Thrown into folds
 Tall columnar cells (Basal nuclei, Pale-staining cytoplasm with vacuoles)
 Basal cells
o Lumen
 Corpora amylacea (prostatic concretions)–Calcified cellular secretions, May appear lamellar

•	Stroma
o	Fibromuscular (collagen and smooth muscle)

Question 21

Prostate: 4 anatomical zones

Answer 21

Transitional zone
o Surrounds prostatic urethra (5%)
o Most benign nodular hyperplasia arise here

Central zone
o Surrounds ejaculatory ducts (20%)

Peripheral zone
o Bulk of gland (70%)
o Most cases of carcinoma arise here

Anterior fibromuscular stroma
o Contains no glandular tissue
o Only part not enclosed by capsule

Question 22

Penis Columns of tissue

Answer 22

Columns of tissue surrounded by connective tissue and skin
- Corpora cavernosa (pl.)
• Two dorsal masses of erectile tissue
- Corpus spongiosum (s.)
• One ventral mass of erectile tisse
• Penile urethra embedded here
- Tunica albuginea
• Fibroelastic capsule around the three erectile tissue masses
- Skin
• Thin and loosely attached by loose superficial fascia, Except at the glans penis

Question 23

Penis: erectile tissue

Answer 23

Wide, irregularly shaped vascular sinuses
• Lined with vascular endothelium
• Surrounded by fibrocollagenous stroma with irregular smooth muscle bundles

Helicine arteries
• Thick-walled anastomosing arteries and arterioles

Question 24

Urethra

Answer 24

Primarily stratified or pseudostratified columnar epithelium
- Penile urethra (spongy urethra): Highly convoluted
- Prostatic urethra: Transitional epithelium
Urethral meatus (external opening): Stratified squamous epithelium

Question 25

Paraurethral glands

Answer 25

* Mucoid secretions for lubrication | * Simple coiled tubular glands

Question 26

Bulbourethral glands

Answer 26

* Pea-sized structure at initial portion of penile urethra * Mucoid secretions for lubrication * Compound tubuloalveolar