Anatomy of testes

Question 1

Where do the testes originate?

Answer 1

Develop in abdomen on posterior abdominal wall behind the peritoneum, then descend. Pass through inguinal canal then interior abdominal wall and acquire 3 layers around them aka the spermatic cord.

Question 2

When do the testes descend? What influences them?

Answer 2

B/w 28 and 32 weeks under influence of gonadotropins (maternal) and androgens (fetal)

Question 3

Describe the descent of the testes

Answer 3

Guided by the gubernaculum down through inguinal canal into scrotum. Simultaneously, it takes an outpouching of peritoneum (processus vaginalis) which will form the coverings of the testes. The proximal end of the processus pinches off (obliterates) and the distal end forms the tunica vaginalis. Space around the testes is ironically called the vaginal cavity.

Question 4

What happens if the processus vaginalis fails to obliterate?

Answer 4

You get congenital hydrocele, or congenital indirect inguinal, or inguino-scrotal hernia in adults (dx with bowel sounds in testes!)

Question 5

What is hydrocele?

Answer 5

Water around the testes. The vaginal cavity fills with fluid.

Question 6

Structures around the testes

Answer 6

Picture

Question 7

Pampiniform plexus of veins in the scrotum

Answer 7

Surround the testicular artery. Act as counter-current temp exchange to cool testes

Question 8

What are the 3 layers around the testes that are acquired during testes descent?

Answer 8

External spermatic fascia, cremaster muscle + fascia, Internal spermatic fascia. Surround the testes and the blood vessels and the Vas deferens.

Question 9

What is cryptorchidism?

Answer 9

Testes don’t descend or not completely. Get stuck in abdominal cavity, at the inguinal canal,

Question 10

Scrotal septum

Answer 10

Layer b/w testes.

Question 11

Tunica albuginea

Answer 11

“white tunic”. Capsule around the testes. Creates septa within testicle, making some 250 lobules of seminiferous tubules.

Question 12

Testicular mediastinum

Answer 12

middle space in testes. Contains the rete - collection of blood vessels.

Question 13

Tranverse cross section of testes

Answer 13

Picture

Question 14

Parasagittal cross section of testes

Answer 14

Picture

Question 15

How do sperm get to vas deferens?

Answer 15

15-20 Efferent ductules, into epididymis (head, body, tail), which leads into the vas deferens.

Question 16

What is in the epithelia of the testes?

Answer 16

The spermatogonia: sperm production. B/w them is the interstitial cells of Leydig: testosterone. Sustentacular cells: inhibin (depress FSH)

Question 17

Describe the path of the vas deferens

Answer 17

Up, through superficial inguinal ring, then inguinal canal, then deep inguinal ring. Then merges with seminal vesicle, then into the ejaculatory ducts which merge within the prostate, then into urethra.

Question 18

Analogy for the spermatic cord

Answer 18

Person wearing shirt, sweater and oversized coat. The shoulder of the shirt is the deep inguinal ring, the lower hanging shoulder of the coat is the superficial ring, and the space b/w them is the inguinal canal. As an aside, a hernia is like another arm squeezing in down the sleeve of the shirt.

Question 19

Where can the testes get stuck?

Answer 19

At the deep or superficial rings or above that.

Question 20

Problems with cryptorchidism

Answer 20

Too warm so infertile, and higher risk of testicular cancer.

Question 21

Erection and ejaculation nervous system control

Answer 21

Erection generated by parasympathetic control (hence morning wood). Ejaculation under sympathetic. Point and Shoot.