Male anatomy

Question 1

What are the two main functions of the testis?

Answer 1

• production of high numbers of spermatozoa (1-25 billion! day) 35,000-200,000/second!
• endocrine gland (=> testosterone)

Question 2

In what order do the tissues that surround testis go? From inwards out.

Answer 2

Tunica albuginea-> visceral layer of tunica vaginalis-> Cavity of tunica vaginalis -> Parietal layer of tunica vaginalis -> external spermatic fascia-> dartos muscle -> skin.

Question 3

What is the visceral tunic made of?

Answer 3

Peritoneal cells.

Question 4

What stuctures comprise the scrotum?

Answer 4

• Parietal vaginal tunic (peritoneum, parietal layer)
• Scrotal fascia
• Tunica dartos (smooth muscle) Scrotum
• Scrotal skin (with sweat glands => cooling)

Question 5

What do seminiferous tubules produce?

Answer 5

Spermatozoa.

Question 6

What do leydig cells produce?

Answer 6

Testosterone. They are found in the interstitial space of the seminiferous tubules.

Question 7

What do sertoli cells do?

Answer 7

Sits on basement membrane and stretches all the way up to where sperm is released in the lumen. They nurse germs cells as they develop from spermatogonium to spermatozoa.

Question 8

What is the seminiferous tubule composed of?

Answer 8

The tubule is composed of a basement membrane and a seminiferous epithelium (germinal epithlium). The epithelium consisits of a basal compartment and adluminal compartment.

Question 9

What are sertoli cells anchored to?

Answer 9

Sertoli cells are anchored to the basement membrane and surround the developing population of germ cells. Sperm production starts in the epithelium near the basement membrane.

Question 10

What 3 parts is the epididymus seperated into and what are their function?

Answer 10

• head (caput): stores sperm until it is ready to undergo maturation. In close association with pampiniform plexus.
• body (corpus: the sperm matures.
• tail (cauda): Storage. The tail, connects to the ductus deferens/vas deferens. Smooth muscle contraction during sexual arousal.

Question 11

Define epididymal transit time?

Answer 11

Time taken for spermatozoa to travel from the proximal head to the distal tail of the epididymis.

Question 12

What does the ductus deferens/vase deferens do?

Answer 12

Connects the epididymis (tail) to pelvic urethra.

Question 13

What does the spermatic cord consist of?

Answer 13

• ductus deferens
• testicular artery and vein (pampiniform plexus)
• nerve and lymphatic supply for testis

Question 14

What are the three functions of the pampiniform plexus?

Answer 14

• heat exchanger
• pulse pressure eliminator
• transfer of testosterone from testicular vein to artery as there is a high local concentration in testis

Question 15

What does the tunica dartos do?

Answer 15

-tunica dartos in the smooth muscle in scrotal skin is important for long lasting contraction which reduces surface area and heat loss.

Question 16

What does the cremaster muscle do?

Answer 16

The cremaster muscle is striated muscle in the spermatic cord that functions for short term elevation of testes.

Question 17

The left and right testicular artery come of what?

Answer 17

The aorta. Testicular arteries are direct branches of the abdominal aorta.

Question 18

The left testicular vein drains into where?

Answer 18

Opens into the left renal vein.

Question 19

The right testicular vein drains into where?

Answer 19

Directly into caudal vena cava.

Question 20

What artery supplies the penis and what does it branch off?

Answer 20

Dorsal penis artery. The internal pudendal artery and this branches off the internal iliac artery.

Question 21

What are the function of accessory reproductive glands?

Answer 21

=>produce seminal plasma (together with epididymis)

Question 22

What is the ampulla?

Answer 22

Ampulla are modified components of the deferent duct.

Question 23

What is the colliculus seminalis?

Answer 23

Opening of ejaculatory ducts: common duct of ampulla and vesicular gland in stallion.

Question 24

What accessory reproductive gland do boars lack?

Answer 24

Ampulla.- but other glands are large = >volurninous ejaculate

Question 25

What are the reproductive glands?

Answer 25

``` Accessory reproductive glands -Ampulla -Vesicular gland -prostate gland 2 parts: body (corpus prostate) disseminate prostate (sits within wall of pelvic urethra) -bulbourethral gland ```

Question 26

What are the only two reproductive glands in the dog?

Answer 26

Ampulla and Prostate (body).

Question 27

What is a sign of benign prostatic hyperplasia | in the dog?

Answer 27

compression of the rectum => tenesmus

Question 28

Which accessory gland does the horse lack?

Answer 28

Disseminate prostate.

Question 29

Which accessory gland do small ruminants lack?

Answer 29

Prostate body.

Question 30

Which accessory glands do cats have?

Answer 30

Prostate body and bulbourethral gland.

Question 31

Which accessory glands do large ruminants have?

Answer 31

All of them.

Question 32

What are some of the functions of seminal plasma?

Answer 32

-needed for dilution and delivery of sperm -contains fructose as energy source (not in stallion) -coagulating (in stallion and boar). In the sow the coagulate blocks the cervix and prevents reflux of semen. - buffer - prostaglandins

Question 33

Where would you find the urethral muscle?

Answer 33

Urethral muscle | =>surrounds the pelvic urethra.

Question 34

Where would you find the bulbospongiosus muscle?

Answer 34

=> surrounds the bulbourethral glands and penile urethra

Question 35

What are the two glandis components of the canine penis?

Answer 35

Pars longis glandis and bulbus glandis

Question 36

What does the root of the penis contain in the dog and other species?

Answer 36

The crura which attach to the ischiatic spine

Question 37

What encloses the crura and is important for erection?

Answer 37

Ischiocavernosus muscle (striated)

Question 38

What is the blood supply for the accessory gland, urethra and penis:

Answer 38

-internal pudendal artery (terminal branch of internal iliac artery)

Question 39

What are the three columns of erectile tissue found in the penis called?

Answer 39

``` -Corpus cavernosum x2 Found at base of the crura main part of the corpus surrounded by dense connective tiss (tunica albuginea) - Corpus spongiosurn x1 Found around the urethra ```

Question 40

What are the two types of penis and what species are they found in?

Answer 40

Fibroelastic (ruminats and pigs) | Musculocavernous (stallion and dog)

Question 41

What are the characteristics of a fibroelastic penis during erection?

Answer 41

-much fibroelastic tissue in CC => during erection little increase in length and girth -sigmoid flexure stretches when retractor penis muscle relaxes.

Question 42

What are the characteristics of a musculocavernous penis during erection?

Answer 42

- more muscular/less connective tissue in CC | - during erection significant increase in length and girth due to filling of corpural spaces.

Question 43

Where would you take swabs from the stallion penis from?

Answer 43

- Urethral process (UP) - Fossa glandis (around UP) - urethral sinus (dorsal to UP) - shaft

Question 44

What two muscles are located in the scrotum and what are their function?

Answer 44

The dartos and cremastor muscle. The dartos is a smooth muscle and is used for long term elevation of the testes. The cremastor muscle is striated and functions for short term elevation of the testes. They both function to ensure optimal temperature for the testicles.

Question 45

What are the origins of the testicular arteries?

Answer 45

They are direct branches of the abdominal aorta.

Question 46

What are the possible functions of the pampiniform plexus?

Answer 46

Heat exchanger Pulse eliminator Transfer of testosterone from testicular vein to artery

Question 47

What is the function of the vaginal cavity in the scrotum?

Answer 47

The vaginal cavity is the space between the scrotal associated tunic (parietal vaginal tunic) and testicular associated tunic (the visceral vaginal tunic) containing peritoneal fluid which prevents adhesion of the two.