Histology: Male Reproductive System

Question 1

What are the reproductive ducts of the male reproductive system?

Answer 1

Epididymis, vas deferens, ejaculatory duct and urethra

Question 2

What are the accessory glands of the male reproductive system?

Answer 2

Seminal vesicles, prostate gland and bulbourethral glands

Question 3

What are the supporting structures of the male reproductive system?

Answer 3

Scrotum, penis and spermatic cords

Question 4

What are the testes surrounded by?

Answer 4

Part of the peritoneal serosa which allows testis to move freely in the scrotum

Question 5

What is the tunica vaginalis?

Answer 5

Visceral aspect of the peritoneal serosa

Question 6

What is the tunica albuginea?

Answer 6

A fibrocollagenous capsule which protects the testes and divides the body of the testes into lobules via septa

Question 7

What are the rete testis?

Answer 7

Channels of ducts within the testes

Question 8

Where are spermatozoa produced?

Answer 8

In germinal epithelia of seminiferous tubules

Question 9

Outline spermatozoa transport in the testis

Answer 9

seminiferous tubule –> rete testis –> efferent ductules –> epidydimis –> vas deferens

Question 10

Outline the order of the testes layers from outermost to innermost

Answer 10

tunica vaginalis (parietal layer) –> serous potential space –> tunica vaginalis (visceral layer) –> tunica albuginea –> testicular lobules

Question 11

What is the function of the testis?

Answer 11

Spermatogenesis (and spermiogenesis) and secretion of male sex hormones (mainly testosterone)

Question 12

What is present at the germinal epithelium of the testes before puberty?

Answer 12

Spermatogonia and Sertoli cells

Question 13

What happens to the germinal epithelium at puberty?

Answer 13

increased testosterone production –> growth of testes –> maturation of seminiferous tubules, gamete production and development of secondary sex traits

Question 14

Where are Sertoli cells located?

Answer 14

Cells rest on the basement membrane of the seminiferous tubule and completely enclose and support the spermatogenic cells

Question 15

What is the role of Sertoli cells?

Answer 15

Secrete regulatory factors for: spermatogenesis & spermiogenesis, Leydig cell function, secretion of tubular fluid and phagocytosis of discarded spermatid cytoplasm

Question 16

Outline the mechanism of action of Sertoli cells

Answer 16

Stimulated by FSH –> secrete ABP –> transports testosterone to lumen of seminiferous tubule –> spermatogenesis

ALSO: secrete inhibin –> regulates pituitary hormone production (LH and FSH)

Question 17

What forms the blood-testis barrier?

Answer 17

Tight junction complexes between Sertoli cells; isolating the antigenically distinct gametes from the immune system

Question 18

Describe the histological structure of Sertoli cells

Answer 18

Oval or triangular nuclei, dispersed chromatin and obvious nucleoli

Question 19

Outline the process of spermatogenesis

Answer 19

Spermatogonia type A –> mitosis –> spermatogonia type B –> mitosis –> primary spermatocytes –> migrate to adluminal compartment –> 1st meiotic division –> secondary spermatocytes –> 2nd meiotic division –> spermatids –> spermiogenesis –> spermatozoa

Question 20

Describe spermiogenesis

Answer 20

Golgi app. makes large vesicle (hydrolytic enzymes) –> attaches to one pole of elongating nucleus –> forms acrosomal head cap (to digest ovum) –> centrioles migrate to opposite end and elongates to form axoneme in centre of flagellum –> 9 fibrils surround elongating flagellum –> cytoplasm migrates around around first part of flagellum (mitochondria concentrate here) in the midpiece –> excess cytoplasm is phagocytosed by Sertoli cells before spermatozoa released into lumen –> sperm won’t develop motility until maturation in the epididymis

Question 21

What is spermiogenesis

Answer 21

Conversion of spermatid to spermatozoa

Question 22

When will a spermatozoa gain motility?

Answer 22

After maturation in the epididymis

Question 23

Name the different parts of the spermatozoa

Answer 23

Acrosome, sperm head, cell membrane, nucleus, mitochondria, centriole, axoneme, midpiece, tail and end-piece

Question 24

What is the function of the epididymis?

Answer 24

Accumulation, storage and maturation of spermatozoa

Question 25

Describe the gross anatomy of the epididymis

Answer 25

Has a head, body and tail region. The head and body have smooth muscle surrounding the tube to produce slow, rhythmic motion to move spermatozoa to vas deferens

Question 26

Describe the histological structure of the epididymis

Answer 26

A muscular tube lined by pseudostratified columnar epithelia with long microvilli (stereocilia)

Question 27

What is the role of stereocilia in the epididymis?

Answer 27

Absorb excess fluid that accompanies the spermatozoa from the testes

Question 28

How is the tail portion of the epididymis affected by the sympathetic nervous system?

Answer 28

Sympathetic nervous system produces strong contractions during ejaculation in the tail region of the epididymis

Question 29

What is the function of the vas deferens?

Answer 29

Transport of spermatozoa from the epididymis to the urethra

Question 30

What is the histological structure of the vas deferens?

Answer 30

Folded mucosa with pseudostratified epithelia, lamina propria, thick muscular wall and surrounded by adventitia (relatively loose fibrocollagenous CT)

Question 31

What type of epithelia is present in the epididymis and vas deferens?

Answer 31

Pseudostratified columnar epithelia

Question 32

Why does the vas deferens have a folded mucosa?

Answer 32

Allows expansion in ejaculation when sympathetic NS causes strong peristaltic contractions

Question 33

What is the function of the accessory reproductive gland?

Answer 33

Secretions make up seminal fluid

Question 34

What is the role of the seminal vesicles in the function of the accessory reproductive gland?

Answer 34

Produces secretion rich in fructose, vitamin C and prostaglandins

Question 35

What is the role of the prostate gland in the function of the accessory reproductive gland?

Answer 35

Produces thin, milky secretion that is rich in citric acid and hydrolytic enzymes such as fibrinolysin which work to liquefy coagulated semen after deposition in female reproductive tract to aid fertilisation

Question 36

Describe the histological structure of the seminal vesicle

Answer 36

Has muscular wall, highly irregular folded lining epithelia

Question 37

How do the seminal vesicles react to sympathetic innervation?

Answer 37

Causes the contraction of the gland, propelling the secretions into the ejaculatory duct soon after the vas deferens has emptied the spermatozoa there

Question 38

Describe the histological structure of the prostate gland

Answer 38

Fibromuscular structure that cosist of tubuloalveolar gland that surround the bladder neck and first part of the urethra, surrounded by thin fibrocollagenous capsule

Question 39

Name the different zones of the prostate gland

Answer 39

Central zone, transitional zone and peripheral zone

Question 40

Describe the central zone of the prostate gland

Answer 40

The part of the prostate around the ejaculatory ducts

Question 41

Describe the transitional zone of the prostate gland

Answer 41

The part of the prostate that surrounds the first part of the urethra (prostatic urethra)

Question 42

Describe the peripheral zone of the prostate gland

Answer 42

Where the prostate lies with the majority of glands

Question 43

What is the function of the male bulbourethral glands?

Answer 43

Make mucous-like product which lubricates penile urethra in arousal (pre-cum)

Question 44

What type of epithelia lines most of the urinary tract?

Answer 44

Urothelium (transitional cell epithelium), which can distend if required

Question 45

What are the three columns of erectile tissue present in the penis?

Answer 45

Two dorsal columns = corpora cavernosa of the penis

One ventral column = corpus spongiosum that surrounds the penile urethra