229 - Histology of the Male Reproductive System

Question 1

Where are mitochondria found in sperm cells?

Answer 1

Middle piece of the tail

Question 2

What is the embryonic origin of spermatogonia?

Answer 2

Hindgut

Spermatogonia = immature sperm cells; they undergo mitotic expansion until it’s time to start making sperm

Question 3

What is the function of prostatic gland secretions in semen?

Answer 3

Liquifies the semen

Question 4

List the stages in sperm development and the relevant changes at each step

Answer 4

• Spermatogonia - under go mitosis
• Primary spermatocytes - Meiosis I
• Secondary spermatocytes - Meiosis II
• Spermatids - Acquire acrosome, mitochondria, shed cytoplasm
• Spermatosoa - Released into seminiferous tubule lumen
  
  • In epididimis: gains motility - sperm are mature, but do not yet have capacity to fertilize (this happens in female tract)
  • Stored in the tail of the epididymis until ejaculation

Question 5

Which cells in the testes perform phagocytosis?

Answer 5

Sertoli cells

Help get rid of sperms that die or are very abnormal

Question 6

Beginning with the testes, list the sequence of structures that sperm travel through to get to the outside world

Answer 6

• In testes:
  
  • Seminiferous tubules
  • Rete testis
  • Efferent ductules of the testis
• Epididymis
• Ductus deferens
• Ejaculatory duct (in prostate gland)
• Prostatic urethra
• Membranous urrethra
• Penile urethra

Question 7

Describe the key histological features of the prostate

Answer 7

Prostatic concretions = Hyaloid material that may be calcified

Also look for:

• Pseudostratified columnar epithelium in glands
• Fibromuscular tissue septa between glands

Question 8

What is spermiation?

Answer 8

Release of mature sperm inot the lumen of the efferent ductules of the testes

Question 9

What are the functions of Leydig and Sertoli cells?

Answer 9

• Leydig cells
  
  • Produce testosterone
• Sertoli cells = epithelium proper
  
  • Blood-testes barrier
  • Secrete androgen binding protein, AMH
  • Phagocytosis

Question 10

Where do sperm acquire motility?

When do they become capable of fertilization?

Answer 10

Motility acquired in the epididymis (as spermatozoa)

Capacitation (the ability to fertilize an ovum) occurs in the female reproductive tract

Question 11

What is the embryonic origin of sertoli cells?

Leydig cells?

Answer 11

Sertolic cells arise from primary sex cords

Leydig cells arise from mesenchyme

Question 12

How long does spermatogenesis take?

Answer 12

74 days from spermatogonia -> spermiation

+ 12 days to swim through the epididymis

=> up to 3 months to see if an infertility tx works

Question 13

Where in the prostate does BPH occur?

Answer 13

Transition zone

Cancer occurs in the peripheral zone

Question 14

Which zone of the prostate is considered “cancer resistant”?

Answer 14

Central zone

Question 15

Which gland lubricates the urethra to prepare for ejaculation?

Answer 15

Bulbourethral gland

Question 16

Which sperm-cell precursors undergo meiosis I?

Meiosis II?

Answer 16

Meiosis I: Primary spermatocytes

Meiosis II: Secondary spermatocytes

Question 17

What is the function of the Pampiniform plexus of the testes?

Answer 17

Heat regulation

Acts as a countercurrent heat exchanger

Question 18

Where in the prostate do most malignant tumors occur?

Answer 18

Peripheral zone

Question 19

Which penile muscle contracts during ejaculation?

Answer 19

Bulbospongiosus

Innervated by pudendal nerve

Note: emission is under sympathetic control; moves sperm from tail of the epididymis to urethra

Question 20

What is the function of the seminal vesicles?

Answer 20

Sperm nutrition

Release fructose

Question 21

What kind of epithelium makes up the efferent ductules and the duct of the epididymis?

Answer 21

Pseudostratified columnar epithelium

True for most of the male system