Male. Carnivore External Genitilia Anatomy

Question 1

What does the male reproductive tract consist of?

Answer 1

—Paired testes
• Production of gametes & hormones
—Paired gonadal tracts
• Epididymis, ductus deferens
• Link to urethra
—Accessory glands
—Urethra
—Penis

Question 2

Name the structural components of male repro tract

Answer 2

On anki

Question 3

What are the 4 accessory glands found in male repro tract

Answer 3

Ampulla, Prostate, Bulbourethral gland & Vesicular glands

Question 4

Functions of male repro tract

Answer 4

Production of:
• Gametes/ spermatozoa
• Androgenic hormones (testosterone)
• Semen- supportive fluid which keeps sperm alive as it travels through female repro system

Introduce sperm to female repro system

Question 5

Name the external genitalia

Answer 5

• Penis
• Prepuce
• Scrotum
•Testes

Question 6

Canine penis
-_______________ type
-contains _________ _______ tissue & ________ ______ tissue

Answer 6

• Musculo-cavernous type
- contains Cavernous sinus tissue & Extensive erectile tissue

Question 7

Penis is made up of 4 main structures;

Answer 7

Root
Body
Glans (bulbus ad pars longa gland is)
OS penis

Question 8

Penis root and body formed from…

Answer 8

2 crura

• Arise from ischial arches
• Combine & form single body
• Urethra incorporated at junction of crura

(Image on anki)

Question 9

2 types of cavernous tissue

Answer 9

Corpus cavernosum
Corpus spongiosum

Question 10

Corpus cavernosum
-what is it
-formed where?
-feature of it
-distal end becomes…

Answer 10

-type of cavernous tissue
-formed in crura of penis
-left & right corpus cavernosum remain divided by septum
-Distal end of corpus cavernosum becomes os penis

Question 11

What is the tunica albuginea? (the one found in penis- there’s 2!)

Answer 11

Casing which surrounds the 2 types of corpus in the crura

Question 12

Corpus spongiosum
-formed from…
-begins at…
-expands what way

Answer 12

-formed from vascular sleeve around urethra
-begins at bulb of penis
-expands distal to corpus cavernosum to. Form glans

Question 13

Show where the corpus cavernosum and corpus spongiosum are found

Answer 13

(On anki)

Question 14

Os penis
-forms from…
-why is it a common site for lower urinary tract obstruction?

Answer 14

Forms from distal end of corpus cavernosum
Contains ventral urethral grooves which encloses urethra as it passes the distal penis. Grooves make it difficult for bladder stones to pass through as urethras ability to expand has been prevented, this causes blockage commonly in dogs.

Question 15

Glans
-formed from…
-2 parts

Answer 15

Formed from corpus spongiosum
-divided into 2 parts internally and externally; bulbous glandis (bulbous part) (proximal expanded part) & pars longus (cylindrical part)

Question 16

What does the pars longus form? And what does it contain?

Answer 16

-forms apex of penis and contains urethral orifice

Question 17

The prepuce
-what is it
-opens in what direction

Answer 17

Invagination of abdominal skin
Opens caudal to umbilicus

Question 18

What’re the 2 types of layers of prepuce?

Answer 18

Laminate externa and lamina interna

Question 19

Which glans in penis is more or less slightly attached

Answer 19

Bulbus glandis more and pars longus less

Question 20

Lamina externa

Answer 20

Outer layer and continuous with skin- basically just skin

Question 21

Lamina interna
-what is it
-appearance and contains what

Answer 21

-Inner layer; lines preputial cavity and continuous with covering of free end of penis
-hairless and contains lots of lymphoid tissue, smegma-secreting preputial glands

Question 22

Is the prepuce fused with the penis?

Answer 22

New horns have it fused but should separate before puberty

Question 23

What are the 2 main problems that can be caused by preputial problems and what can they lead to?

Answer 23

—congenital narrowing of preputial orifice
-prevents extrusion of penis which causes phimosis

—paraphimosis
-inability to retract penis which leads to impaired circulation (must be dealt with quickly)

Question 24

Name the 4 penile muscles

Answer 24

• Bulbospongiosus (Single) - Continuation of urethralis- carries on as muscular sleeve around urethra

• Ischiocavernosi (paired & powerful) - Arise from ischium & enclose crura

• Ischiourethralis (single)
- Passes to fibrous ring enclosing penile veins

• Retractor penis (paired)
- Arise from caudal vertebrae
- Pass lateral to anal canal & along perineum and teach to penis and region of prepuce. Smooth muscle

Question 25

Penile anterial supply
-2 major supplies

Answer 25

-internal pudendal artery
-external pudendal artery

(On anki)

Question 26

Name the 3 branches of internal pudendal artery of penis that supply the penis

Answer 26

Dorsal artery of penis
Deep artery of penis
Artery of bulb

Question 27

What part of penis does the dorsal artery of penis supply

Answer 27

Both Glans
A little to prepuce

Question 28

What part of penis does the deep artery of penis supply

Answer 28

Supplies corpus carvonosum

Question 29

What part of penis does the artery of bulb supply

Answer 29

Corpus spongiosum and proximal part of penis

Question 30

Name the arteries which come from the external pudental artery and what do they supply

Answer 30

Preputial arteries
-supply dorsal part of penis
-the prepuce

Question 31

Penile venous drainage
—describe the;
-bulbus glandis
-pars longa & prepuce drainage systems

Answer 31

Bulbus glandis drains through dorsal vein which also collects blood from corpus cavernosum & bulb of penis. This then drains into internal pudental vein

Pars longus & prepuce drain into external pudental vein, but also into bulbus glandis causing same process as already described above

(Diagram on anki)

Question 32

What do the valves in drainage systems prevent?

Answer 32

Prevent reflux

Question 33

Describe the 2 stages of Canine penile erection

Answer 33

1st Stage
- Increased blood flow via arteries - Occlusion of venous outflow
- Dilation of cavernous spaces due to arterial pressure

2nd Stage
- Contraction of ischiocavernosus & bulbospongiosus
- Blood forced into cavernous space above arterial pressure (undergo rhythmic contrations)

(Diagram on anki)

Question 34

What is the “tie” action of dogs

Answer 34

When during mating dog dismounts and faces away from bitch. Corpus spongiosum expands more than corpus cavernosum in the male. Their sex organs are locked together and will not release until the males genitalia (specifically bulbus glandis) stops being swollen. Eventual relaxation of bulbospongiosus allows escape of blood and they are released. You should not tear them apart as it would be very painful

Question 35

Feline penis

Answer 35

• Musculocavernous
• Remains in embryonic position
- Caudoventrally directed apex
- Urethral groove dorsal
• Prepuce thick & short
- Orifice faces caudally

• Shorter than canine penis
• Os penis present but not commonly seen during imaging
• Small glans with small keratinised spines
• Bulbourethral glands near bulb of penis
• Erection results in cranioventral direction of apex penis

Question 36

Name components of feline penis

Answer 36

On ankiii

Question 37

Scrotum- external features
-location
-what is it and what does it contain

Answer 37

Location varies between species; canine= intermediate
And feline= perineal
Thin layer of skin that protects the testicles, important for thermo regulation
contains sweat & sebaceous glands, and various hair covering and a groove between left and right half

Question 38

Scrotum- internal features/ structures

Answer 38

-Skin lined internally by fibromuscular layer called dartos- a combo of smooth muscle and fibrous skin tissue
-internal septum formed from dartos divides right ad left compartments
-contains testes
-fascia lining which supports vaginal tunic

Question 39

Name structural components of scrotum

Answer 39

On anki

Question 40

Vaginal tunic
-what does it do
-2 layers

Answer 40

Encloses spermatic cord (structures that supplies testes), testis and epididymis (covers them)

2 layers- parietal layer (outer) and visceral layer (inner layer)

Question 41

What is the space between layers of vaginal tunic for?

Answer 41

Small amount of fluid

Communication with peritoneal cavity

Question 42

Inguinal Canal
-what is it
-functions
-contains…

Answer 42

• Slit between caudal abdominal wall muscles
• Runs between superficial & deep inguinal rings
• Allows transmission of testes to scrotum as animal develops

Contains; - Spermatic cord
- Outpouching of peritoneum
- External pudendal vessels.

Question 43

Superficial inguinal ring

Answer 43

Terminal end of inguinal canal

Question 44

Deep inguinal ring

Question 45

Why is the sheep prostate difficult to find?

Answer 45

The sheep does not have a compact prostate - diffuse prostatic tissue is present, but is within the wall of the pelvic urethra, so not visible on a gross anatomic specimen.