The Equine Pelvis. Flashcards
What is pelvimetry?
The different measurements within the pelvis.
What is the transverse diameter of the pelvis?
The widest point between the 2 acetabula.
What is the conjugate diameter of the pelvis?
The vertical line that runs from the pecten to the promontory of the sacrum.
What is the vertical diameter of the pelvis?
The line that runs from the pecten of the pubis to the ventral surface of the sacrum or CD-1.
The vertical diameter of the pelvis is usually at what angle to the pelvic floor?
Perpendicular.
What shape is the entrance to the equine pelvis?
It is round and quite large.
How does the amount of soft tissue in the lateral walls of pelvis of the horse compare to that in the dog and cat?
There is a lot more soft tissue found in the lateral walls of the pelvis of the horse.
What name is given to the soft tissue in the lateral walls of the pelvis?
The sacrotuberous ligament.
How large is the pelvic cavity in the horse?
It is fairly roomy.
How does the angle of the floor of the equine pelvis compare to that of the cow?
The floor of the equine pelvis is much flatter and this makes giving birth much easier.
How does the shape of the pelvic entrance differ between the mare and the stallion?
In the mare it is wide and round.
In the stallion it is triangular.
Is the sacrotuberous ligament well developed in the horse?
Yes.
What shape is the horizontal axis of the equine pelvis?
It is fairly straight and there are no curvatures.
Where is the scrotum of the stallion located relative to the pelvis?
They are ventral to the cranial end of the pelvis.
What shape is the scrotum of the stallion?
It is globular with no distinct neck.
Where is the scrotum of the stallion located?
In between the thighs.
Can the scrotum of the stallion be seen from a caudal view?
No.
Is the scrotum of the stallion covered in any hair?
No.
It has a shiny/oily appearance.
What divides the scrotum of the stallion into 2 halves?
The median scrotal raphe.
What artery supplies the scrotum of the stallion?
The external pudendal artery.
What are the 3 tissue layers that make up the scrotum of the stallion?
The skin.
The tunica dartos.
A number of fascial sheaths.
What is the tunica dartos that makes up the scrotum of the stallion?
A layer of fibroelastic tissue and smooth muscle that lies just below the skin.
Is the tunica dartos easy to separate from the skin?
No.
What is the function of the scrotal ligament?
It attaches the tunica dartos to the spermatic sac (vaginal tunic).
What are the 2 fascial sheaths of the scrotum of the stallion?
The external spermatic fascia.
The cremasteric fascia and the cremaster muscle.
The internal spermatic fascia.
What is formed by the tunica dartos in the midline of the scrotum?
The scrotal septum.
What is the external spermatic fascia of the scrotum?
It is part of the fascial sheath and it attaches to the tunica dartos.
What muscle does the external spermatic fascia of the scrotum arise from?
The external abdominal oblique muscle.
The cremasteric fascia and cremaster muscle arise form what muscle?
The internal abdominal oblique muscle.
What muscle does the internal spermatic fascia of the scrotum arise from?
The transversus abdominis muscle.
What part of the scrotum is the internal spermatic fascia attached to?
The vaginal tunic.
What layers of the scrotum are dissected when performing close castration?
Close castration involves cutting through the external spermatic fascia and no further.
What layers of the scrotum are dissected when performing close castration?
All 3 layers are cut so that we can enter the cavity of the vaginal tunic.
What does close castration involve?
Separating the skin and external spermatic fascia from the cremasteric fascia.
The cavity of the vaginal tunic is continuous with what other body cavity?
The peritoneal cavity.
What nerves supply the scrotum of the stallion?
Spinal nerves L2 and L3 and there is also some supply from the preputial and scrotal branch of the pudendal nerve.
Where are the scrotal (superficial inguinal?) lymph nodes found in the stallion?
Around the spermatic cord.
What shape are the testes in the stallion?
The are round or flattened mediolaterally.
The long axis of the testes of the stallion is orientated in what direction?
Horizontally.
Where is the spermatic cord located relative to the long axis of the testes of the stallion?
It is located perpendicularly to the long axis of the testes.
Is the mediastinum testis visible in the horse?
Not really.
The epididymus of the stallion is located on what aspect of the testes?
On the dorsal aspect of the testes.
Does the head of the epididymus of the stallion project beyond the testes?
The head of the epididymus projects slightly beyond the cranial pole of the testes.
Does the tail of the epididymus of the stallion project beyond the testes?
The tail of the epididymus projects slightly beyond the caudal pole of the testes.
Is the ligament of the tail of the epididymus well formed in the stallion?
Yes.
What is the function of the ligament of the tail of the epididymus?
It attaches the tail of the epididymus to the vaginal tunic.
What is the function of the proper of the epididymus?
It attaches the tail of the epididymus to the caudal pole of the testes.
Where does the deferent duct of the epididymus leave the epididymus?
At the tail and it ascends cranially as part of the spermatic cord.
What is the major artery that supplies the testes of the stallion?
The testicular artery.
What about the blood supply to the testes of the stallion is unique to the horse?
The tortuous branches that are formed on the testes by the blood vessels.
Where is the testicular artery found relative to the spermatic cord?
It is found on the caudal border of the spermatic cord.
What shape is the testicular artery as it approaches the testes?
It is tortuous.
What organs are supplied by the testicular artery?
The testes.
The epididymus.
What is the pampiniform plexus?
a network of veins that surround the testicular artery as it enters the testes.
Does the paminiform plexus surround the testicular vein?
No.
In the stallion, which blood vessels run along with the ductus deferens?
The cremasteric/deferent artery and vein
What lymph node is found near the testes?
The medial iliac lymph node.
What colour is the parenchyma of the testes in the stallion?
Yellow.
How do the lymphatic vessels travel to the medial iliac lymph node of the testes?
They follow the same course as the testicular veins.
How does open castration occur?
We cut through the skin to the vaginal process.
How does closed castration occur?
The skin, the tunica dartos and the external spermatic fascia are cut.
Then the testes are removed.