B Pharmacy Anatomy Questions On Lesser Omentum

B Pharmacy Anatomy Question and Answers

Question . Write a short note on Lesser Omentum.
Answer:

Lesser omentum:

• It is a double-layered fold of the peritoneum between the lesser curvature of the stomach and under the surface of the liver.
• Inferiorly, it is attached to the lesser curvature of the stomach and proximal 2 cm of the duodenum.
• Superiorly, it is attached to the margins of porta hepatis and fissure for ligamentum venosum of the liver.

Parietal Peritoneum

Lesser omentum Contents:

• Along the leisure curvature of the stomach:
  • Right and left gastric arteries.
  • Right and left gastric lymph nodes.
• In the right free margin:
  • The portal vein, posteriorly.
  • Hepatic artery and bile duct anteriorly (with duct being on the right side).

Question. Draw a labeled diagram to show the horizontal tracing of the peritoneum above the transverse colon/supra colic compartment. 
Answer:

Lesser Omentum And Greater Omentum

Horizontal tracing of the peritoneum:

Question. Write a short note on lesser sac/omental bursa.
Answer:

Lesser sac/omental bursa:

• The lesser sac/omental bursa is a large recess of the peritoneal cavity behind the stomach, lesser omentum, and caudate lobe of the liver.
• It communicates with the greater sac of the peritoneal cavity through the epiploic foramen.

Lesser sac/omental bursa Boundaries:

1. Anterior wall: It is formed by
   • Caudate lobe of the liver
   • Lesser omentum
   • Anterior two layers of the greater omentum
2. Posterior wall: It is formed by
   • Posterior two layers of the greater omentum
   • Structures forming the stomach bed, viz.
     • Diaphragm
     • Left kidney
     • Left suprarenal gland
     • Pancreas
     • Transverse mesocolon
     • Splenic artery
     • Spleen

Lesser sac/omental bursa Recesses:

The lesser sac presents 3 recesses:

1. Superior: Lies behind the lesser omentum and liver
2. Inferior: Lies within the greater omentum
3. Splenic: Lies between the gastrosplenic and lienorenal ligaments

Lesser sac/omental bursa Functions:

• It facilitates the movements and dilatation of the stomach.
• It acts as a bursa.

Lesser sac/omental bursa Applied anatomy:

• Pseudocyst of the pancreas: The collection of fluid in the lesser sac following acute pancreatitis is called the pseudocyst of the pancreas.
• The lesser sac is used by surgeons to reduce the strangulated internal hernia.

Question. Write a short note on the epiploic foramen/foramen of Winslow. 
Answer:

Epiploic foramen:

The epiploic foramen is an opening of about 3 cm in size through which the lesser sac communicates with the greater sac. It is vertically placed behind the lesser omentum.

Epiploic foramen Boundaries:

Epiploic foramen Anterior:

• Right free margin of lesser omentum containing portal vein.
• Posteriorly and hepatic artery and bile duct anteriorly with duct being to the right of the artery.

Epiploic foramen Posterior:

Inferior vena cava, right suprarenal gland, and T12 vertebra.

• Superior: Caudate process of the caudate lobe of the liver.
• Inferior: First part of the duodenum and horizontal part of the hepatic artery.

Epiploic foramen Applied anatomy:

1. Internal hernia:
   • Occasionally, a loop of the small intestine may herniate through this foramen into the lesser sac producing an internal hernia. It often becomes strangulated by the edges of the foramen.
   • None of the boundaries of the foramen can be incised/enlarged to release the strangulation; therefore, the bowel must be decompressed by a needle to allow its reduction.
2. Compression of hepatic pedicle:
   • The hepatic pedicle is the right free margin of the lesser omentum containing the portal vein, hepatic artery, and bile duct.
   • If the cystic artery is torn during cholecystectomy, hemorrhage can be controlled by compressing the hepatic artery (hepatic pedicle) between the index finger within the epiploic foramen and the thumb on its anterior wall.
   • This enables the damaged vessel to be identified and secured.
3. Spread of infection: The epiploic foramen allows the spread of infection from the greater sac to the lesser sac and vice versa.

Question. Write a short note on Morison’s pouch (hepatorenal pouch).
Answer:

Morison’s pouch:

The right subhepatic space (i.e., right posterior intraperitoneal subphrenic space) is called hepatorenal pouch/Morison’s pouch.

Morison’s pouch Boundaries:

• Posterior: Peritoneum covering the diaphragm and upper pole of the right kidney.
• Anterior: Inferior surface of the right lobe of liver and gall bladder.
• Above: Posterior/inferior layer of the coronary ligament.
• Below: It opens into the general peritoneal cavity.

Morison’s pouch Applied anatomy:

• Anteriorly, Morison’s pouch communicates with the right anterior intraperitoneal space around the sharp anterior margin of the right lobe of the liver.
• In case an abscess forms in this space, it is usually prevented from spreading around the sharp margin of the liver into other subphrenic spaces by the formation of adhesion between the transverse colon and the anterior border of the liver.
• Since Morison’s pouch is the most dependent part of the abdominal cavity proper in supine position, it is the most common site of the subphrenic abscess.
• The fluid may track in this pouch from a perforated peptic ulcer, appendix, or gall bladder.

Question. Write a short note on the recto-uterine pouch (pouch of Douglas).
Answer:

Recto-uterine pouch:

The rectouterine pouch or the pouch of Douglas is located between the rectum and the uterus. It is the most dependent part of the peritoneal cavity when the body is in an upright position and the most dependent part of the pelvic cavity below the pelvic brim in the supine position.

Recto-uterine Boundaries:

• Anterior: Uterus and the posterior fornix of the vagina.
• Posterior: Rectum
• Inferior (floor): Rectovaginal fold of the peritoneum

Recto-uterine Applied Anatomy:

• Pelvic abscess: During inflammation of the peritoneal cavity, the pus tends to collect here as it is the most dependent part of the peritoneal cavity.
• Posterior colpotomy: The rectouterine pouch can be drained either through the rectum or through the posterior fornix of the vagina by inserting a needle (posterior colpotomy). The floor of the pouch is 5.5 cm from the anus and can be easily felt with a finger passed through the rectum or the vagina.