Male Histology

Question 1

What are Leydig cells, where are they located and what is secreted by Leydig cells?

Answer 1

Leydig cells are interstitial cells that secrete testosterone. In some species they also secrete fair amounts of estradiol as well.

Question 2

red spots in Leydig cell cytoplasm. What are these dots? Why are they present?

Answer 2

Lipid (cholesterol) droplets, they provide the cholesterol precursor form testosterone synthesis

Question 3

What are the functions of Sertoli cells?

Answer 3

The three main functions of Sertoli cells are: 1) maintain developing germ cells, that is to act as ‘nurse cells’ for germ cells undergoing spermatogenesis; 2) secrete inhibin, which acts in the negative feedback loop to decrease FSH levels; and 3) synthesize androgen binding protein, which in turn maintains high levels of testosterone in the sertoli cell, which is required for the sertoli cell to maintain the developing spermatozoa.

Question 4

What is different about the microanatomy of an infantile testis, cryptorchid testis, and a normal testis?

Answer 4

Infantile: No lumen, no developing germ cells.
Cryptorchid: Only a single layer of germ cells located at the very surface of seminiferous tubules.
Normal: Seminiferous tubules have lumen, numerous ‘stages’ of sperm development.

Question 5

what do spermatogonia look like? (note location, size and shape)

Answer 5

Small round purple cells with very little cytoplasm, located at the basement membrane of the seminiferous tubules

Question 6

what do spermatocytes look like? (note location, size and shape)

Answer 6

Larger purple cells, in which condensed chromosomes can be seen, located just off the basement membrane of the seminiferous tubules

Question 7

what do round spermatids look like? (note location, size and shape)

Answer 7

Small round purple cells located from the spermatocytes to the lumen of the STs

Question 8

What do elongated spermatids/spermatozoa look like? (note location, size and shape)

Answer 8

Elongated sperm heads at the lumen of the STs

Question 9

What cell types proliferate in a seminoma?

Answer 9

Germ cells

Question 10

How would you recognize an interstitial adenoma?

Answer 10

Tumor cells are red/pink, separate seminiferous tubules from each other. Leydig cells.

Question 11

How would you recognize a Sertoli cell tumor?

Answer 11

Light pink tumor causing destruction of ‘normal’ seminiferous tubule structure, inducing joining of many ST’s into a single looking structure.

Question 12

Could you recognize a testis producing few/no sperm? How?

Answer 12

Few or no stages with elongated spermatids

Question 13

You are not likely to see the efferent ducts in these slides. However, what is their role?

Answer 13

Provide connection from testis to epididymis

Question 14

Does the epithelium look similar in all regions of the epididymis? Why or why not?

Answer 14

Cells are larger in caput vs cauda, microvilli longer in caput vs cauda. Caput cells need to absorb large quantities of testicular fluid and synthesize proteins involved in sperm maturation

Question 15

What is the function of microvilli as contrasted to cilia?

Answer 15

Microvilli are involved in absorption, cilia move things.

Question 16

What is the role of the smooth muscle? Is it thicker in the head or tail? Why?

Answer 16

The smooth muscle contracts to move sperm through the epididymis, it is thicker in the tail as sperm from this region need to be moved longer distances - to the ductus deferens.

Question 17

Are sperm in the body of the epididymis capable of fertilization?

Answer 17

Only sperm in the tail of the epididymis.

Question 18

What is different about epididymal tissue in cryptorchids? Can you provide a reason?

Answer 18

Cells smaller and little to no microvilli, compared to cells from a ‘normal epididymis’.
the Cryptorchid testis has no spermatogenesis, therefore, Sertoli cells are not functioning (producing testicular fluid). The epididymal cells, therefore, do not need microvilli to absorb incoming fluid, or make proteins to mature sperm.

Question 19

What is the type and function of the lining epithelium?

Answer 19

Pseudostratified columnar

Question 20

Are sperm motile while in ductus deferens?

Answer 20

No

Question 21

What is the role of the heavy muscularis layer of ductus deferens?

Answer 21

Move spermatozoa to the urethra.

Question 22

Should the ductus deferens be palpable within the scrotum, in a living male?

Answer 22

Yes, in many species

Question 23

What does the secretory epithelium look like accessory sex glands?

Answer 23

Most common is pseudostratified columnar secretory epithelium, contain abundant secretory granules. Appear like rows of a picket fence resting next to each other, connected by cell adhesion molecules

Question 24

Answer 24

Epididymus, tail

Question 25

Answer 25

Testis, interstitial cell adenoma

Question 26

Answer 26

Epididymus, head cryptorchid

Question 27

Answer 27

bull ductus deferens

Question 28

Answer 28

prepubertal testis

Question 29

Answer 29

normal testis

Question 30

Answer 30

horse epididymus

Question 31

Answer 31

testis, sertoli cell tumor

Question 32

Answer 32

pubertal testis, rete, epidiymys

Question 33

Answer 33

subnormal horse testis

Question 34

Answer 34

testis - seminoma