Male Reproductive Histology

Question 1

What are the innermost layers of the scrotal wall?

Answer 1

Mesothelium, Tunica albuginea, and tunica vasculosa

Question 2

System in the testis

Tunica albuginia

Answer 2

Tough fibrous capsule

Question 3

Excretory Ducts

Rete testis

Answer 3

Carries sperm out of the testis by connecting a series of efferent ducts that form part of the head of the epididymis.

Question 4

Seminiferous Tubules​

Answer 4

Question 5

System in the testis

Tunica vasculosa

Answer 5

Sends septa into the testis to divide it into 250-300 lobules.

Question 6

System in the testis

Seminiferous tubules

Answer 6

Are a loop through each lobule

Question 7

System in the testis

Tubuli recti

Answer 7

Connect each ST at each end (straight tubules) to a network of channels called the rete testis

Question 8

System in the testis

Rete testis

Answer 8

Go to efferent ducts, then the head of the epididymis and from there to the tail of it and the ejaculatory duct.

Question 9

Excretory Ducts

Epididymis

Answer 9

Head and tail form a single coiled tube where sperm mature and are temporarily stored. Continuous with vans deferens which conveys sperm away from scrotum along spermatic cord during ejaculation.

Question 10

Spermatogenesis

What is it?

Answer 10

The process of proliferation and maturation which transforms diploid spermatagonia into haploid spermatozoa

Question 11

Spermatogenesis

Type A dark spermatagonia

Answer 11

Form a pool of self renewing stem cells but can also form Type A pale spermatagonia. These divide mitotically to form Type B spermatagonia.

Question 12

Spermatogenesis

Type B spermatagonia

Answer 12

Further divide mitotically to form primary spermatocytes

Question 13

Spermatogenesis

Primary spermatocytes

Answer 13

Pass through meiosis I to form secondary spermatocytes

Question 14

Spermatogenesis

Secondary spermatocytes

Answer 14

Rapidly undergo meiosis II to produce spermatids

Question 15

Spermatogenesis

Spermatids

Answer 15

Undergo a maturation process called spermiogenesis to produce spermatozoa - there is no division in this step, it is a cellular change

Question 16

Clonal Syncytium

What is it?

Answer 16

An intercellular bridge which only breaks when the spermatozoa are released. This is because the cells do not undergo full cytokinesis

Question 17

Sertoli Cells

What do they do?

Answer 17

Are support within the seminiferous tubules. Very important both in supporting the newly developing spermatozoa and in controlling how the process proceeds. They extend all the way from the basal lamina to the lumen of the tubule. Their cytoplasm ramifies and surrounds all of the developing cells.

Question 18

Function of Sertoli Cells

Secrete

Answer 18

Factors regulating spermatogenesis, spermiogenesis and Leydig cells. Also secrete tubular fluid.

Question 19

Function of Sertoli Cells

Phagocytose

Answer 19

Discarded spermatid cytoplasm

Question 20

Function of Sertoli Cells

Via tight junctions

Answer 20

Divide the tubule epithelium into two compartments

Question 21

Blood-Testis Barrier

Answer 21

Question 22

Spermiation

What is it?

Answer 22

Release of the spermatozoa by the Sertoli cells into the lumen. Immotile and incapable of fertilization until swept through rete testis and epididymis by fluid flow and peristalsis, after which it will become capable.

Question 23

Intertubular Tissue

What is it?

Answer 23

Found between seminiferous tubules. Loose connective tissue, blood vessels, nerves and lymphatics. Also clusters of Leydig cells which produce testosterone.

Question 24

Efferent Ducts

What are they?

Answer 24

About 12 ducts which carry the sperm from the rete testis to the head of the epididymis. Lined by ciliated pseudostratified columnar epithelium and most fluid from the testis is absorbed here.

Question 25

Epididymis​

What is it?

Answer 25

A highly coiled tube about 5m in length. Lined by pseudostratified columnar epithelium with stereocilia and ensheathed by smooth muscle cells. Sperm stored here for about a week while they mature.

Question 26

Vas Deferens

What is it?

Answer 26

Lined by pseudostratified columnar epithelium with stereocilia. This is surrounded by lamina proporia and is able to expand during ejaculation. 3 coats of muscle, inner and outer longitudinal with a middle circular layer. Innervated by sympathetic nervous system, producing a strong peristalsis during ejaculation.