Chapter 111: Testes, Epididymides and Scrotum

Question 1

What are the three layers of the scrotum?

Answer 1

• Skin
• Tunica dartos (poorly developed smooth muscle and elastic fibers)
• Scrotal fascia

Question 2

What are the three different cell types which make up the seminiferous tubules within the testes?

What do they do?

Answer 2

1. Spermatogenic cells
2. Sertoli (sustentacular) cells
   - Support development and maturation of spermatozoa
   - Controls release of spermatazoa into tubules
   - Form the blood-testis barrier
   - Stimulated by FSH, negative feedback via inhibin
3. Leydig cells
   - Lie within spaces between seminiferous tubules
   - Produce testosterone
   - Negative feedback with LH

Question 3

What is the function of the epididymis?

Answer 3

Store spermatazoa until they are released with ejaculation

Question 4

What are the secondary sex glands of the dog and cat?

What do they do?

Answer 4

• Dog: prostate
• Cat: prostate and bulbourethral glands (thicker fluid)

Produce seminal fluid which is alcaline and helps sperm survive acidic female repro tract

Question 5

What structure is responsible for the migration of the testis into the scrotum?

Answer 5

The gubernaculum

Question 6

What 3 physiologic factors are involved in thermoregulation of the scrotum?

Why is it important?

Answer 6

• Skin is thin and lightly haired, little SQ fat and abundant sweat glands
• Cremaster muscle and tunica dartos to move testes farther away or closer to the body as needed
• Countercurrent thermoregulation in the pampiniform plexus

Seminiferous tubule temp needs to be 2-3 degrees cooler that the body for viable production of spermatazoa

Question 7

Which testis is more caudal?

Answer 7

Left

Question 8

What is the epididymis?

Answer 8

A tightly coiled tube that connects the efferent ducts to the vas deferens.

Question 9

What is in the spermatic cord?

Answer 9

Ductus deferens
testicular artery
pampiniform plexus
lymphatics
nerves
cremaster muscle