Histology Of Male Reproductive System

Front 1

Testis 2 major functions

Back 1

1) Production of sperm SPERMATOGENESIS
2) Synthesis of androgens STEROIDOGENESIS

Front 2

Testosterone

Back 2

• Essential for spematogenesis
• Embryonic development into male fetus
• Male physical characteristics

Front 3

TESTIS

Back 3

Front 4

Tunica albuginea

Back 4

Thick layer
Dense irregular connective tissue

Front 5

Seminiferous Tubules

Back 5

Front 6

Seminiferous Tubules histology

Back 6

Front 7

SERTOLI CELLS

Back 7

DO NOT DIVIDE
 blood-testis barrier & support (physical and nutritional)
 Columnar epithelia
 Extensive cytoplasmic processes
 extends thru complete epithelial thickness (unlike the layers in spermatogenic cells)

Front 8

Blood-Testis Barrier

Back 8

Front 9

Spermatogenic cells

Back 9

REPLICATE AND DIFFERENTIATE
1. Spermatagonia
immature, rest on basal lamina
divide by mitosis
2. Spermatocytes
Undergoing 2 meiotic divisions to reduce
chromosome number to produce haploid cells
3. Spermatids
attached to Sertoli Cell apical surface (non-motile)
differentiate into mature sperm (spermiogenesis

Front 10

Seminiferous Tubules Sperm Production

Back 10

Front 11

Seminiferous Tubules with sperm

Back 11

Front 12

Seminiferous Tubules
MYOID CELLS

Back 12

Front 13

LEYDIG CELLS

Back 13

Front 14

SPERMATOGENESIS

Back 14

Front 15

SPERMIOGENESIS

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Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa

Front 16

Spermiogenesis process

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 Nuclear volume shrinks to 1/40th
 lysosomal enzymes produced by golgi and
accumulate in a membrane-bound vesicle
= Acrosome (accumulate in the head of nucleus)
 Centriole initiates assembly of tail 9 + 2 microtubule doublets = Axoneme (cytoplasma follows and elongates)
 Mitochondria wrap around the proximal part
of the growing flagellum

 Sertoli cells phagocytose excessive cytoplasm
 cytoplasmic bridges (aka junctions) between cells destroyed
 Spermatid free from surface

Front 17

Sperm Microscopically

Back 17

Front 18

MATURE SPERM

Back 18

74 days to become a mature sperm
NON- motile
carried in fluid produced by Sertoli Cells
stored in duct of epididymis (2 week life span) & acquire their motility
3 day life span in Vagina (acidic envirnoment when the ejaculate is alkaline)
Section thru tubule see all stages of differentiation

Front 19

Epididymis

Back 19

Front 20

Epididymis Histology

Back 20

Front 21

PROSTATE GLAND

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Front 22

Prostate Histology

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Front 23

PENIS

Back 23

Corpora cavernosa
2 dorsal masses of erectile tissue

Corpus spongiosum
1 ventral mass of erectile tissue
Urethra embedded in this tissue

Tunica albuginea
Dense, fibroelastic layer
Binds the 3 corpora together
Forms a capsule around each corpora

Front 24

Semen

Back 24

SPERM + FLUIDS = SEMEN
Sperm from the seminiferous tubules
Fluids from...
1. epididymis, ductus deferens (nutrients)
2. seminal vesicles (fructose, prostaglandins)
3. prostate gland (enzymes, liquefier)
4. bulbourethral gland (mucus)

Front 25

PENIS Histology

Back 25

Front 26

Penis Histology 2

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Front 27

corpus cavernosum of penis

Back 27

• numerous wide, irregular shaped vessels
lined with endothelium
• surrounded by smooth muscle which forms
trabelulae within the tunica albuginea
• many nerve endings & lymphatic vessels in the
interstitial connective tissue between vessels

NOT MUCH CONNECTIVE TISSUE THUS NOT MUCH SPACE
* NOT SINUSOIDS BUT VESSELS

Front 28

corpus spongiosum of penis

Back 28

• penile urethra runs thru this corpora
• numerous wide, irregular shaped vessels
lined with endothelium
• surrounded by more connective tissue than the
corpora cavernosum
Thus; remains less turgid, allowing semen
to travel thru the urethra
• many nerve endings & lymphatic vessels in the
interstitial connective tissue between vessels

Front 29

Urethra Epithelium

Back 29

The urethral epithelium is stratified
- initially, next tobladder, is transitional epithelium (dome shaped cells on top of columnar cells)
- then becomes more of a stratified squamous epithelium next to the skin

Front 30

Erection and ejaculation

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Erection is a vascular event initiated by CNS
1. Parasympathetic stimulation via acetylcholine and NO
relaxes the smooth muscle dilates the helcine arteries
2. Results in filling of the corpora
3. Blood accumulates in these vessels due to compression
against the rigid t. Albuginea
4. venous outflow also blocked by compression
= tumescence (rigidity) of the penis
5. Sympathetic stimulation causes Ejaculation
and contraction of smooth muscle in helcine arteries
6. leads to decreased blood flow
7. Lowers the pressure in the corpora vessels
8. Allows blood to drain from the corpora