L21 - Histology of the Male Reproductive System

Question 1

Tract the drainage of sperm in the testis?

Answer 1

Seminiferous tubule > Straight tubule > Rete testis > Efferent ductules > Epididymis

Question 2

Describe the internal organization of testis?

Answer 2

Tunica albuginea = thick connective tissue capsule surrounding testis

Extensions of t. albuginea form septa: separate lobules

Question 3

Describe the lining and function of seminiferous tubules in testis?

Answer 3

1-4 coiled tubes in each lobule:

• Lined by Stratified Germinal epithelium
• Location of spermatogenic cell division, maturation and transform into sperm

Question 4

Function of the Vas deferens?

Answer 4

• Connect epididymis to ejaculatory duct

- Strong smooth muscle contraction expel sperm during ejaculation

Question 5

Define the brief functions of each accessory gland in male reproductive tract?

Answer 5

• Bulbourethral gland = lubricating mucus secretion, neutralize vaginal acidity
• Prostate = proteolytic enzyme to breakdown clotting factors in ejaculate for sperm fluidity
• Seminal vesicles = most of semen secretion, rich in fructose, ions, anti-oxidants…etc

Question 6

Define the erectile tissue in penis?

Answer 6

three masses of erectile tissue:

• paired corpora cavernosa
• corpus spongiosum

Question 7

Define the epithelium and cell type in: Seminiferous tubules

Answer 7

Stratified Germinal epithelium (thick)

Surrounded by thin layer of connective tissue

Sertoli cells + spermatogenic cells sit on thick basal lamina

Question 8

Define the epithelium and cell type in: Straight tubules and Rete testis

Answer 8

Simple cuboidal epithelium

Lined by sertoli cells and simple cuboidal cells with short microvilli and single flagellum

Question 9

Define the epithelium type in: Efferent ductules

Answer 9

Columnar epithelium with cilia

Question 10

Define the epithelium and cell type in: Epididymis

Answer 10

Pseudostratified columnar epithelium with stereocilia

Principal cells with stereocilia, surrounded by Basal cells and smooth muscle

Question 11

Define the epithelium and smooth muscle type in: Vas deferens and ejaculatory duct

Answer 11

Pseudostratified columnar epithelium with stereocilia (like epididymis

3 layers of smooth muscle:

• Inner longitudinal
• Circular intermediate
• Outer longitudinal

Question 12

Define the epithelium type in: Seminal vesicles, prostate and Bulbourethral glands

Answer 12

glandular epithelium

Question 13

Define the epithelium type in: Urethra?

Answer 13

transitional epithelium
→ pseudostratified or stratified columnar
→ non-keratinzed stratified squamous epithelium

Question 14

Type of structural connective tissue in testis?

Answer 14

• Tunica albuginea: dense, irregular connective tissue

- invaginate and continues as Interlobular septa and Mediastinum testis

Question 15

Type of cell found in interstitium of testis?

Answer 15

In connective tissue: Leydig cells and Myofibroblasts

Question 16

Which cells have Reinke crystals in testis?

Answer 16

Leydig cells

Question 17

Define the cell types in seminiferous tubules?

Answer 17

Germinal epithelium:

Sertoli cells + Spermatogonia

Question 18

Describe the process of spermatogenesis in seminiferous tubule in testis?

Answer 18

1) Spermatogonium diploid (2n)
2) Develop into primary spermatocyte
3) a primary spermatocyte generates two secondary spermatocytes
4) Two haploid spermatids (haploid cells) are generated by each secondary spermatocyte, total = four spermatids
5) Spermiogenesis (maturation) into spermatozoa

Question 19

Function of Sertoli cells?

Answer 19

Partially envelop germ cells:

• Support, protect and nourish spermatogenic cells
• Phagocytose cytoplasmic remnants of spermatids
• Signalling germ cells, Leydig cells
• Establish the blood-testis barrier****

Question 20

What cell provides the testis with immunological previledge?

Answer 20

Sertoli cells form adjacent tight junctions near basal lamina of seminiferous tubule > blood-testis barrier

Question 21

Describe how sertoli cells continue to provide protection for developing spermatocytes moving into lumen of seminiferous tubule?

Answer 21

New tight junctions continue to form behind moving spermatocytes&raquo_space; continue to envelop

Question 22

Describe the cell types and structure of the interstitium of testis?

Answer 22

Interstitium = space between basal lamina and adjacent seminiferous tubules

Leydig cells, Fibroblasts, mast cells, macrophages

Rich in collagen

Question 23

How do seminiferous tubules increase sperm expulsion?

Answer 23

Outer wall of seminiferous tubules have myoid cells

> > contraction to propel sperm to lumen

Question 24

Location and function of Leydig cells in testis?

Answer 24

Dispersed in clusters through interstitial tissue between seminiferous tubules

Synthesis of testosterone

Question 25

Histological appearance of Leydig cells?

Answer 25

Large round nucleus Abundant sER and Golgi Contains crystals of Reinke

Question 26

What do efferent ductules connect in testis? Function?

Answer 26

pierce tunica albuginea to carry sperm from rete testis to epididymis Resorb most luminal fluid secreted by the Sertoli cells Ciliated columnar cells move the spermatozoa

Question 27

Define the secretions by Seminal vesicles?

Answer 27

* fructose (provide energy), * ascorbic acid, (antioxidant), * stimulators of sperm motility: potassium, bicarbonate, magnesium, prostaglandin, •semenogelin:coagulum formation, inhibit sperm capacitation and motility

Question 28

Describe the epithelium of seminal vesicles?

Answer 28

Glandular epithelium: - Highly convoluted/ invaginated, irregular epithelium - Supported by extensive lamina propria - 2 layers of Muscularis: inner circular, outer longitudinal - Adventitia

Question 29

Describe the epithelium in prostate?

Answer 29

Glandular epithelium: - Simple columnar cells arranged in glandular acini, surrounding large irregular lumen - Fibromuscular stroma extend throughout - Dispersed Prostatic concretions

Question 30

What marker is used to Dx Benign prostate hyperplasia? Which zone of prostate secretes this?

Answer 30

PSA Transitional zone: anterior to Periurethral gland zone

Question 31

Describe the epithelium in Bulbourethral (Cowper's) gland?

Answer 31

Tubular alveolar glands: Simple columnar cells arranged in acini with large, irregular lumen

Question 32

Function of Bulbourethral gland secretion?

Answer 32

slippery, mucous fluid which lubricate the urethra + tip of penis Neutralize any acidity from residual urine in the urethra + acidity of the vagina

Question 33

Anatomical location and opening of the Bulbourethral glands?

Answer 33

At roof of penis, embedded in muscle of urogenital diaphragm Excretory duct terminate at proximal penile urethra

Question 34

Define the 3 erectile tissue in penis?

Answer 34

Corpus cavernosum Corpus spongiosum

Question 35

Define the histological layers of the penis from superficial to deep?

Answer 35

- Superficial fascia (Colles' fascia) - Deep fascia (Buck's fascia) - Tunica albuginea - Erectile tissue: i) Paired Corpus cavernosum with deep artery of penis at center ii) Corpus spongiosum with urethra in center

Question 36

Epithelium of erectile tissue of penis?

Answer 36

Irregular vascular spaces with vascular epithelium

Question 37

Define the 6 layers of the scrotum

Answer 37

- Skin - Dartos muscle and fascia - External spermatic fascia - Cremasteric muscle - Internal spermatic fascia - Parietal and visceral Tunica Vaginalis

Question 38

Describe the epithelium, epidermis and dermis of skin at scrotum?

Answer 38

epithelium: thin, corrugated and pigmented; epidermis: keratinized squamous epithelium dermis; divided in half by a midline cutaneous raphe

Question 39

Describe the function and structure of Dartos muscle and fascia in scrotum?

Answer 39

two coherent plexuses of smooth muscle cells; contracts in cold or during sexual stimulation

Question 40

Which layer of the scrotum carry oblique muscles?

Answer 40

External spermatic fascia: continuation of external oblique aponeurosis Cremasteric muscle: bundles of skeletal muscle, continuation of internal oblique muscle

Question 41

What does the internal spermatic fascia connect?

Answer 41

Attach transversalis fascia to tunica vaginalis