Equine Abdomen Flashcards
When is the musculoaponeurotic boundary evident?
- musculoaponeurotic boundary of the external oblique muscle
- evident in horses suffering from heaves
- > expiratory difficulty
- > known as the heave line
Superficial Thoracic Vein
- Known as the spur vein
- may be obvious during heaves
- > can be bruised after a raise because its where the riders spur hits when they kick
Where is the cutaneous muscle well developed?
- in the superficial fascia
- ventral line from the withers to the stifle joint
Rectus abdominis muscle
- provides insertion for other muscles by means of the linea alba that separates the left and right muscles
- > linea alba is strong and supportive and relatively avascular
Rectus Sheath contains
- Orientation to rectus abdominis
- Dorsal: Transverse abdominal muscle to insert on linea alba
- Ventral: External abdominal oblique muscle and internal abdominal oblique muscle to insert on linea alba
Superficial (external) Inguinal Ring
- slit in the aponeurosis of the external oblique muscle
- > divides into lateral and medial crura of the aponeurosis
Lateral Crus of the superficial inguinal opening
- connected to the medial thigh fascia by CT
- > Femoral Lamina (ONLY IN THE HORSE)
Femoral Lamina
- ONLY in the HORSE
- when the hip joint is maximally extended, there is a lot of pull on the lateral crus of the superficial inguinal opening which causes an inguinal hernia in the horse
- > can occur when the hindlimb of a stallion slips or during mating
Inguinal Hernia
- passage of any of the abdominal viscera through the vaginal ring into the cavity of the vaginal process
- > uncommon in horses
How can you palpate for an inguinal hernia?
- the vaginal ring can be palpated per rectum
Stomach Characteristics
- small and simple
- left craniodorsal part of the abdominal cavity!!!!!
- remarkably flexed with a close opening and exit, so deep angular notch (similar to lesser curvature)
- NO contact with the abdominal floor even when full
Where is the stomach of the horse found?
- Left craniodorsal aspect of the peritoneal cavity
- the stomach is inaccessible by rectal palpation, or through flank incision
- > will not see it with a midventral incision, or a flank incision because it is dorsal to the colon
Saccus cecus
- the blind sac above the esophagus
- > in the pig it is the ventricular diverticulum
Margo plicatus
- divides the distal glandular mucosa from the proximal non-glandular abrasive mucosa
Why do horses not eructate nor vomit?
- The esophagus enters the lesser curvature of the stomach quite obliquely
- The cardiac sphincter is very thick and effective
- Most well developed of the species
How many pyloric sphincters are in the horse?
- two well developed pyloric sphincters guarding the narrow pyloric exit
- > cranial and caudal
Greater Omentum Ligaments
- Gastrophrenic Ligament
- greater curvature to crura of diaphragm - Gastrosplenic ligament
- from stomach to spleen
* *3. Lienorenal (renosplenic) Ligament
- attaches the left kidney to the spleen**
Why clinical complications can the lienorenal (renosplenic) ligament have?
- loops of intestine can get trapped within it
Why clinical complications can the lienorenal (renosplenic) ligament have?
- loops of intestine can get trapped in it
Where is the descending duodenum attached to?
- descending duodenum is related to the right kidney and passes around the base of the cecum
What is the descending duodenum closely related to?
- descending duodenum is related to the right kidney and passes around the base of the cecum
Where do the loops of the jejunum sit?
- loose coils mostly on the left caudodorsal part of the abdominal cavity
- mixed with coils of the small colon
Epiploic Foramen location
- between the right lobe of the liver and the descending duodenum
What is a clinical problem involving the epiploic foramen
- the foramen enlarges as the right lobe of the liver atrophies with age
- > Loops of the jejunum can get strangulated at the foramen
