Lecture 30: Histology of the Male Reproductive System

Question 1

What produces sperm and androgen?

What transports sperm?

Answer 1

Testes

epididymis, ductus deferens, ejaculatory duct, urethra

Question 2

What organs specialize in semen production and sperm nutrient source?

Answer 2

seminal vesicle

prostate gland

bulbourethral glands

Question 3

Testes

Histological features

Answer 3

• dense CT capsule called tunica albuginea, thick at the back (mediastinum testes)
• tunica vaginalis covering the capsule (parietal and visceral layers)

Question 4

Seminiferous tubules
Epithelium?
Contains?

Answer 4

• highly convoluted tubules lined with seminiferous epithelium
• epithelium has sertoli and spermatogenic cells, tubules surrounded by Leydig and myoid cells

Question 5

Interstitial cells of Leydig

Cellular features

Answer 5

• lots of MT and sER containing lipid droplets

- with myoid cells and fibroblasts

Question 6

What are the features of sertoli cells?

What are the features of spermatogenic cells?

Answer 6

Sertoli: columnar cells with cyclops nucleus and extensive processes that surround the spermatogenic cells, they nurse the spermatogenic cells

Spermatogenic: become mature sperm, immature ones in the basal lamina with mature ones in the apical portion

Question 7

What is the sertoli-sertoli cell junctional complex?

Answer 7

sertoli cells bound to each other to form the blood testis barrier

Question 8

What is the significance of the blood testis barrier?

Answer 8

divides the epithelium into basal and luminal compartments

basically prevents immature sperm (diploid) from mixing with circulation (haploid) until its ready (has to get through the complex once mature)

Question 9

why are Sertoli cells called “nurse cells”?

Answer 9

they provide nutrients and phagocytose residual bodies

Question 10

Once in the luminal side, what happens to the spermatid that cross the blood testis barrier?

Answer 10

• start as round spermatids

- later move to apical crypts of Sertoli cells and become elongated spermatids

Question 11

How are mature spermatids released from the testis to the epididymis?

Answer 11

Spermiation process:

Intercellular bridges separates the residual bodies from the mature spermatids > spermatids are propelled into the epididymal duct

Question 12

Describe the features of sperm

Answer 12

Head: has acrosome cap with lots of enzymes and has flattened and elongated nucleus

Tail: Middle (has MT), principal and end piece

Question 13

What is the pathway of sperm transport?

Answer 13

straight tubules > rete testis > efferent ductules > epididymis > ductus deferens > ejaculatory duct

Question 14

Epididymis
structure
features of the epithelium?

Answer 14

• highly elongated/coiled duct where sperm matures (gains forward motility)
• pseudostratified columnar with principal and stem cells

Question 15

What are the other features of the epididymis?

Answer 15

-thin circular layer of smooth muscle cells + additional inner and outer longitudinal muscle layers in the tail region (where sperm is stored)

Question 16

Ductus deferens
epithelium?
Structural features?

Answer 16

• Pseudostratified columnar with sparse stereocilia

- has inner and outer longitudinal layers and middle circular layer, outer layer has loose CT and adipocytes

Question 17

Other features of the ductus deferens?

Answer 17

Ampulla - dilated portion that leads to prostate glands, distal ends form the ejaculatory ducts after merging with the seminal vesicle duct

Question 18

What are the accessory glands of the male tract and what are their major functions?

Answer 18

2 seminal vesicles, 1 prostate gland, 2 bulbourethral glands, urethral glands

major function is produce seminal fluid

Question 19

Seminal vesicles
epithelium?
structural features?
Major function?

Answer 19

• pseudostratified columnar with external CT capsule
• also has inner and outer longitudinal smooth muscle layers
• make alkaline secretions rich in fructose and prostaglandins

Question 20

Describe the structure of the prostate gland

What is its major function?

Answer 20

• collection of glands that are embedded in dense fibromuscular capsule
• produce Zn rich alkaline fluids that neutralizes acidic vaginal envt and nourishes sperm

Question 21

How are the glands of the prostate arranged around the urethra?

Answer 21

• Transition zone glands surround the superior urethra
• Central zone glands surround the transition zone, surround the ejaculatory ducts
• Peripheral zone glands (majority) surround the central zone

Question 22

How are the secretions of all the glands of the prostate secreted?

Answer 22

All glands converge and empty into the prostatic urethra (mixes with secretions from the seminal vesicles and tubules)

Question 23

What are the features of the individual prostate glands?

Answer 23

• has simple columnar or pseudostratified epithelium

- lumen has the corpora amylacea (with glycoproteins and Ca2+ deposits)

Question 24

Describe the structural features of the penis

Answer 24

• erectile tissues include 2 corpora cavernosa (covered with tunica albuginea)
• 1 ventrally located corpus spongiosum that surrounds the penile urethra, glans penis at distal end

*these tissues have sinuses that fill with blood

Question 25

How does an erection occur?

Answer 25

ANS > vasodilation > blood fills the sinuses within the erectile tissues > dorsal veins press against the tunica albuginea > venous outflow blocked causing the penis to harden