L42: Comparative Penile Anatomy

Question 1

What is a penis?

Answer 1

Copulatory organ involved in both ejaculation and urination

Question 2

What are the two penis types (according to structure)?

Answer 2

• Musculocavernous penis

- Fibroelastic penis

Question 3

Which species have the musculocavernous penis?

Answer 3

Dog, horse, cat

Question 4

Which species have the fibroelastic penis?

Answer 4

Bull, ram, buck, boar

Question 5

Both types of penis have what 2 types of tissue?

Answer 5

• Fibroelastic

- Membranous (erectile)

Question 6

The musculocavernous penis has an increase and a decrease of which tissues?

Answer 6

Increase % of Erectile & muscular tissue

Decrease % of fibroelastic tissue

Question 7

The fibroelastic penis has an increase and a decreasae of what tissues?

Answer 7

Decrease % of Erectile & muscular tissue

Increase % of fibroelastic tissue

Question 8

What are the muscles of the penis root? (4)

Answer 8

1. Ischiourethralis
2. Ischiocavernosus
3. Bulbospongiosus
4. Retractor penis

Question 9

What is ischiocavernosus?

Answer 9

Erector of the penis

Question 10

What is the bulbospongious innervated by? action?

Answer 10

Innervated: deep perineal nerve
Action: Contracts the urethra to expel remnants of urine or semen

Question 11

What is the Retractor penis muscle innervate by? Action?

Answer 11

Innervated: Deep perineal nerve
Action: Retracts penis, notably action in fibroelastic penis

Question 12

Where are the fibroelastic tissue and the membranous tissue present?

Answer 12

Fibroelastic: Tunica albuginea & trabeculae
Membranous: Erectile tissue

Question 13

What structure contributes to tying during mating?

Answer 13

Bulbis glandis

Question 14

Ovulation in the cat is induced by the stimulus of __?

Answer 14

Spikes

Question 15

Penis is innervated by what nerve?

Answer 15

Pudendal nerve

Question 16

What 3 structures are mainly supplying the blood to penis?

Answer 16

• Cavernous bodies
• Spongy body
• Bulbus glandis

Question 17

What does erection result from?

Answer 17

Positive balance of blood flow- more blood accumulates in the penis as the venous drainage is interrupted

Question 18

When an erection happens, which muscles are being constricted? (2)

Answer 18

1. Ischiourethralis muscle

2. Vestibular bulb

Question 19

While the musculocavernous penis erection is the result of __________, in the fibroelastic penis it is the result of the extension of the sigmoid flexure.

Answer 19

Extensive blood filling

Question 20

In the musculocavernous penis, there is a ___ blood filling of cavernous and spongy bodies

Answer 20

Large

Question 21

In the fibroelastic penis, there is a ___ blood filling of cavernous and spongy bodies- what else is there?

Answer 21

Reduced; extension of sigmoid flexure

Question 22

In the bull and boar, glans morphology changes at the maximum stage of erection because of the _____ of penis

Answer 22

Spiraling

Question 23

What is a prepuce?

Answer 23

Musculocutaneous shield that covers and protects the penis

Question 24

What are the prepuce muscles of the bull? (2)

Answer 24

1. Preputial cranialis (protractor)

2. Preputial caudalis (retractor)

Question 25

What is the blood supply coming form for the prepuce? (2)

Answer 25

1. External pudenal artery

2. “ vein

Question 26

What is the innervation of prepuce? (3)

Answer 26

• Pudendal n
• Iliohypogastric n
• Ilioinguinal n

Question 27

Where are the places of lymphatic drainage of penis and prepuce? (4)

Answer 27

1. lumbar nodes
2. internal iliac nodes
3. deep inguinal node
4. superficial inguinal node