Carnivore Internal Genitalia

Question 1

Carnivore testis
-functions
-found where
-contained within
-size

Answer 1

Sits outside body cavity

• Endocrine & exocrine functions
->Production of gametes (optimal below body temperature)
• Contained within vaginal tunic
• Relatively small compared to farm animals

Question 2

Testis: capsule

Answer 2

-Outer capsule also called Tunica albiguniea
-CT with small amount of smooth muscle
-large blood vessels run through it (pattern is species characteristic)

Question 3

Testis: parenchyma
-what is it
-colour
-bulk made up of…
-what else does it contain

Answer 3

Tissue of the testis- contained in capsule under pressure

• Soft, yellow-brown
- bulk made up of Interstitium: comprised of Leydig cells & connective/ vascular frame
- interstitium supports the Seminiferous tubules which are Lobules formed by invaginations of capsule
• Central mediastinum:
- Contains Rete Testis which the seminiferous tubules drain into as well.

Question 4

Where is sperm produced and how is it ejected

Answer 4

Produced in seminiferous tubules- drains into mediastinum into Rete testis. Sperm carried to head of epididymis and ejected during ejaculation from tail of epididymis through prostatic urethra

Question 5

Epididymis
-3 parts of it
-attachments
-lies in what direction
-what runs through it

Answer 5

-head, body, tail
-head & tail firmly attached to testis
-body loosely attached near testicular bursa
-lies along dorsal margin of testis (carnivores) (palpable as a ridge along the testis)
-Efferent ductules combine to form convoluted
epididymal duct which runs through epididymis- exit tail of epididymis to form deferent duct/ vas deferens

Question 6

What is the order in which sperm travels through epididymis?

Answer 6

Head-body-tail

Question 7

Function of epididymis

Answer 7

Allows sperm storage & maturation of sperm

Question 8

Name the testicular attachments

Answer 8

• Proper ligament of testis: attaches tail of epididymis to testis
• Ligament of tail of epididymis: attaches tail to parietal tunic
• Scrotal ligament: attaches parietal tunic to scrotum

Question 9

Spermatic cord is contained within…

Answer 9

Vaginal tunic

Question 10

What does the spermatic cord contain?

Answer 10

• Deferent Duct
• Deferent Artery & Vein
- Arise from Prostatic Vessels
• Testicular Artery & Vein
• Lymphatics
- Drain to sublumbar nodes
• Testicular Nerves
- Sympathetic
• Cremaster Muscle

Question 11

What is the deferent duct/ductus deferens/ vas deferens -describe its physiological structure

Answer 11

A duct of the testis; exits tail of epididymis and carries sperm to Prostatic urethra

-initially undulates then straightens up as it runs up the side
-accompanies testicular vessels in spermatic cord & uns through inguinal ring and runs over dorsal bladder neck
-enters prostate & joins urethra

Question 12

What is different about the vas deferens in the dog

Answer 12

There is a slight dilation of ampulla at entry to prostate

Question 13

Testicular artery

Answer 13

• Vessels form bulk of spermatic cord

• Testicular artery
- Branch from abdominal aorta
- Runs to vaginal ring
- becomes Extremely convoluted as it runs distally
- Cranial & caudal epididymal branches

Question 14

Testicular vein
-Starts as…
-what is its function

Answer 14

Starts as Elaborate complex pampiniform plexus of vessels
- these vessels Wrapped around distal convoluted testicular artery which acts as a Heat exchange mechanism

(Arterial blood comes down to testis; cooled as it passes between the vessels and this helps reduce temp before it reaches testis for sperm production)

-plexus vessels combine to form single vein running to caudal vena cava

Question 15

Cremaster muscle
-what is it
-origin
-runs along ________ and supported by _______

Answer 15

Thermoregulatory mechanism
Thin layer of muscle
-originates from internal abdominal oblique- caudal to deep inguinal ring
-runs along parietal vaginal tunic and supported by spermatic fascia

Question 16

What is the function of cremaster muscle

Answer 16

When it contracts; draws testis closer to body wall which ^ testicular heat

Question 17

Testicular descent regulated by what?

Answer 17

Gubernacuulum of the testis

Question 18

What actually is the gubernaculum of the testis

Answer 18

-mesenchymal wall structure that extends from abdominal testis which runs through inguinal canal and into scrotum at the end
-incorporates peritoneum
-forms vaginal tunic

Question 19

What are the three sub layers of gubernaculum

Answer 19

• Pars propria: within visceral layer of vaginal process
• Pars vaginalis: around parietal layer of vaginal process
• Pars infravaginalis: distal to invagination

Question 20

What does the swelling of the gubernaculum do?

Answer 20

• Swelling of gubernaculum opens inguinal canal & draws testis into scrotum

Question 21

Describe what happens in this image involving the gubernaculum and entrance of the testis into scrotum. (Testicular descent)

Answer 21

On anki

Question 22

What is Cryptorchidism

Answer 22

Failure of testis to descend into scrotal sac

Question 23

Cryptorchidism-
Testis should be in scrotal sac by what age?
Undescended testes most commonly located in what region?
Unilateral or bilateral?
Can develop what?

Answer 23

-2 months
-inguinal canal
-both
-neoplasia- so must be removed

Question 24

What are the internal reproductive organs?

Answer 24

• Urethra
• Accessory Reproductive Glands

Question 25

Name the 3 accessory reproductive glands Cats or dogs have which?

Answer 25

- Ampullary Glands (only dog) - Prostate (dogs and cats) - Bulbourethral glands (only cats)

Question 26

What is produced in the prostate gland?

Answer 26

The bulk of the semen

Question 27

Urethra (male) -runs from where to where -what is it

Answer 27

• Runs from internal orifice at bladder neck through the pelvis down through penis out to external orifice found at tip of penis • Mucosal tube with vascular submucosa (comes in to be corpus spongiosum) & outer muscular tunic

Question 28

What are the 2 regions of the urethra

Answer 28

• Two regions: - Pelvic or Internal Urethra (runs through pelvic canal) - Penile or External Urethra (runs down penis)

Question 29

Pelvic/internal urethra -initially contained within what -contains what -lies in what direction and what does it contain

Answer 29

• Initially contained within prostate • contains Dorsal ridge projecting into lumen called - Seminal Colliculus • Caudally lies along pelvic floor with Muscular sleeve: urethralis (striated) - Contains thin layer of cavernous tissue - Widens caudal to prostate - Narrows over pelvic outlet

Question 30

What does the seminal colliculus/dorsal ridge contain?

Answer 30

- contains Openings of deferent ducts and Openings of prostatic ducts

Question 31

What does the prostatic duct within seminal colliculus drain?

Answer 31

drains secretions from prostate.

Question 32

Role of deferent ducts in seminal colliculus

Answer 32

Carry’s sperm into urethra

Question 33

Penile urethra -runs through what

Answer 33

• Runs through penis between cavernous tissues • Runs through groove of os penis - Potential obstruction by bladder stones

Question 34

Ampullary glands

Answer 34

Found in dog • Dilation of terminal vas deferens before entering prostrate - Lies dorsal to bladder • Lined with glandular tissue • Produce a small proportion of ejaculate/seminal fluid • have a Capsule & septa with smooth muscle (very small structure in dog so difficult to find) - Assist in expulsion of fluid

Question 35

Prostate -produces what -2 parts -where is it found when small and enlarged -smaller in what animal

Answer 35

• Produces bulk of seminal fluid Two parts: - Large compact part around proximal urethra (bilobed) - Vestigial disseminated part within urethral mucosa • found Within pelvic cavity when small • May be found within abdominal cavity if enlarged or in entire mature dogs • Smaller in cats

Question 36

True or false urethra is completely enclosed in prostate in dogs True or false urethra is completely enclosed in prostate in cats

Answer 36

True False- ventral urethra free

Question 37

Prostate physiological structure

Answer 37

Divided into left & right lobes by dorsal groove & internal septum Smooth capsule containing smooth muscle and contains small ducts which drain into urethra

Question 38

What isProstatic enlargement caused by Seen with what? What does this cause?

Answer 38

commonly due to hormonal influence - called Benign Prostatic Hyperplasia • Seen with inflammation, neoplasia & cystic diseas • May cause compression of rectum (or urethra)

Question 39

What does compression of rectum cause?

Answer 39

Constipation

Question 40

What imagine structures can be used to se: -testis -urethra -prostate

Answer 40

• Testis: Easily imaged using ultrasound to detect testicular masses • Urethra: Contrast radiography (pelvic urethra difficult to see via ultrasound) • Prostate: Ultrasound (best), can see on radiographs if enlarged