3. Male Reproductive Histology II

what are the secondary organs of the male reproductive system?

-excurrent ducts--> seminiferous tubule termini, straight tubules, rete testis, efferent ductules, epididymis & duct of epididymis, ductus deferens (w/ ampulla & ejaculatory duct), & urethra

-glands--> seminal glands, prostate, urethral glands, preputial glands

-penis

Are the following intratesticular or extratesticular excurrent ducts?

-seminiferous tubule termini

-tubuli recti testis (straight tubules)

-rete testis

intratesticular

Are the following intratesticular or extratesticular excurrent ducts?

-duct of the epididymis

-ductus deferens (w/ ampullae & ejaculatory ducts)

-urethra

extratesticular

which ducts are apart of the proximal excurrent duct system?

-tubuli recti (straight tubules)

-rete testis

-efferent ductules

-epididymis --> head, body, & tail

how is the terminal part of the seminiferous tubules histologically different than the rest of the tubule?

only made up of sertoli cells

*only allow sperm to flow forward (no back flow)

what type of epithelium lines the tubuli recti?

simple cuboidal epithelium

Longitudinal Section of Seminiferous Tubule Terminus

Scanning of cross section seminiferous tubule terminus

which intratesticular excurrent duct is described by the following?

-lined w/ simple cuboidal epithelium

-few microvilli

-collect sperm & propel them downstream via fibromuscular stroma

rete testis

Scanning EM of Rete Testis

what is the function of the rete testis?

collect sperm & propel them downstream via the fibromuscular stroma

which intratesticular excurrent duct is described by the following?

-lined w/ pseudostratified columnar epithelia

-short cells w/ microvilli

-tall cells w/ cilia

-star shaped lumen

-surrounded by smooth muscle

-resorbs most fluid from the testis

efferent ductules

What forms the star-shaped lumen of the efferent ductules?

combination of short cells w/ microvilli + tall cells w/ cilia

what is the function of the short cells of the efferent ductules?

reabsorbs testicular fluid

*have microvilli to increase surface area for reabsorption

what is the function of the tall cells of the efferent ductules?

transport of sperm (b/c sperm are non-motile --> can't move on their own yet)

All the ducts from the efferent ductules to the prostatic urethra are lined with what type of epithelia?

pseudostratified columnar epithelia

which part of the male reproductive tract is the only area of ciliated cells?Why?

efferent ductules

*b/c sperm mature & learn to swim in later areas of the tract (don't need the help of cilia past this point in the tract)

what are the red granules seen in the epithelial cells of the efferent ductules?

lysosomes

What reabsorbs approximately 90% of testicular fluid?

short cells of the efferent ductules

epididymis

What does the following describe?

-long-coiled tube (4-6m)

-lined w/ pseudostratified columnar epithelia

-tall principal cells w/ stereocilia for fluid absorption

-basal stem cells

-smooth apical surface/ smooth luminal surface

epididymal duct

what is the function of the epididymis?

-secrete products for sperm maturation --> forward mobility protein

-stores sperm in tail prior to ejaculation

what is the function of the forward mobility protein?

give sperm the ability to swim forward

*secreted by the epididymal ducts

how many layers of smooth muscle does the proximal epididymus contain?

1

how many layers of smooth muscle does the epididymus contain near the tail?

3

approximately how long does it take sperm to travel through the epididymus?

12 days

where is sperm stored prior to ejaculation?

tail of the epididymus

epididymal duct

Scanning EM of epididymal principal cell stereocilia

epididymal duct v. efferent ductules

Ductus Deferens (vas deferens)

what is described by following?

-lined w/ psuedostratified columnar epithelia w/ stereocilia

-single lumen that's not as smooth as the epididymal ducts

-has 3 smooth muscle layers that contract during ejaculation

ductus deferens

what are the 3 smooth muscle layers of the ductus deferens? What is their function?

-inner longitudinal m

-middle circular m

-outer longitudinal m

*all contract during ejaculation

Why is there a congenital absence of the vas deferens (CAVD) in patients with cystic fibrosis?

b/c the CFTR protein (defective in cystic fibrosis) participates in the development of portions of the epididymus, vas deferens, & seminal vesicles

what is the function of the plexus of veins within the spermatic cord?

counter-current cooling of blood

spermatic cord

efferent ductules v. epididymal ducts v. ductus deferens

what is the structure of the seminal vesicles?

coiled tube that forms a gland

-mucosa--> pseudostratified columnar epithelium

>principal secretory cells

> basal cells

>lamina propria

-muscularis --> smooth muscle

-adventitia/serosa

The following describes which glands?

-secrete alkaline fluid rich in fructose, prostaglandins, coagulating substances (seminogelins & fibronectin), flavins, ascorbic acid, & inositol

-major source of seminal fluid (60%)

seminal vesicles

why is fructose secreted in seminal fluid?

used as energy source for sperm cells

*secreted by seminal vesicles

what is the function of the prostaglandins secreted in seminal fluid?

-stimulate sperm motility

-stimulate oviduct contractions

*secreted by & stored in seminal vesicles

what are the coagulating substances that the seminal vesicles secrete into seminal fluid?

-seminogelins

-fibronectin

what gives semen a yellow tint?

flavins secreted into the seminal fluid by the seminal vesicles

seminal vesicles

The following describes the structure of which gland ?

-parenchyma --> compound tubuloalveolar glands w/ psuedostratified columnar epithelium

-stroma --> capsule & fibromuscular tissue to support glands

-copora amylacea --> concretions

prostate

which part of the prostate gland is made up of compound tubuloalveolar glands with pseudostratified columnar epithelium?

parenchyma

which part of the prostate gland is made up of a capsule & fibromuscular tissue?

stroma

what are corpora amylacea?

concretions w/in lumen of prostate glands

what is PSA?

serine protease secreted by the prostate gland that liquefies the gel formed the seminal vesicular seminogelins & other factors in semen

what is the largest male accessory gland?

prostate

What is the only male accessory gland that's common to all mammals?

prostate

How much of the total seminal fluid is produced by the prostate?

approx 25%

what is the function of the prostate?

secrete alkaline fluid rich in proteolytic enzymes PSA, fibrinolysin, Zn., substrates to enhance sperm viability

what are the blebs seen on a trichrome of the prostate gland due to?

apocrine secretion

H&E Stain of Prostate

True or False: HMW Actin immunohistochemistry is specific for the basal cells of the prostate

False ==> HMW Keratin IHC is prostate basal cell specific

True or False: There is an absence of prostate basal cells in adenocarcinoma

True ==> loss of basal cells w/ prostate cancer

seminal vesicle v. prostate

the following describes the function of which glands?

-secretes clear alkaline mucus fluid

-only active upon sexual stimulation

-lubricates urethra & neutralizes residual urine

bulbourethral glands of cowper

what type of epithelia lines the portion of the urethra that's closet to the bulb of the penis?

transitional epithelium

what type of epithelia lines the portion of the urethra that's in the middle of the penis?

pseudostratified/stratified columnar

what type of epithelia lines the portion of the urethra that's closest to the glans penis?

SSNKE

why is there less connective tissue surrounding the corpus spongiosum than the corpus cavernosum of the penis?

b/c the urethra passes thru the corpus spongiosum --> less squeezing shut to allow flow of urine/semen (allows urethra to be open)

cross section of penis

what is the function of the urethral glands?

-line urethra

-mucous producing

-protect urethra from urine