1-6 Anatomy of the Supracolic Compartment Flashcards
What is the supracolic compartment?
Peritonealized area between the thoracoabdominal diaphragm and the transverse colon and its associated mesocolon
What are the contents of the supracolic compartment?
Contains the distal esophagus stomach, spleen, liver, gall bladder, and part one of the duodenum
What abdominal compartment is the transverse mesocolon in?
Since the transverse mesocolon straddles the pancreas, it is retroperitoneal and not in either the supra or infracolic compartment
What is the origin of the esophagus?
cricoid cartilage opposite CV6
What is the course of the esophagus?
- Neck: slightly to the left of the midline
- Upper thorax (TV4): midline
- Middle thorax (TV8): crosses to the left (anterior to aorta)
- Lower thorax (TV10): left of the midline to penetrate the diaphragm
What are the 4 sites of potential constriction for the esophagus?
- At the junction of the pharynx and esophagus, cricopharyngeus m. (upper esophageal sphincter)
- Aortic arch
- Left primary bronchus
- Esophageal hiatus
At what level does the esophagus pierce the diaphragm?
TV10
What ligament allows for independent movement of the esophagus and diaphragm during breathing?
phrenico-esophageal ligament
Attached to the margins of the esophageal hiatus via the phrenico-esophageal ligament (dorsal mesentery). It attaches to the esophagus both superior and inferior to the hiatus, allowing independent movement of the esophagus and diaphragm during breathing
At what level does the esophagus join the stomach?
TV11
What portion of the esophagus is peritonealized?
Mesoesophagus, in abdomen
Describe the right and left borders of the gastro-esophageal junction.
- Right border - continuous with the lesser curvature of the stomach
- Left border - separated from the fundus of the stomach by the cardiac notch
Describe the āz-lineā of the esophagus.
demonstrates an epithelial transitional zone (stratified squamous to simple columnar, aka, āZā line)
Is there a sphincter at the esophageal cardiac junction? What is this important in? What does it prevent?
Although not anatomic, a functional physiologic sphincter exists at the esophageal cardiac junction (L.E.S. lower esophageal sphincter) which appears to be important in regulating the entrance of food into the stomach and in preventing esophageal reflux
What is the arterial supply for the cervical, thoracic, and abdominal portions of the esophagus?
- Cervical portion: Inferior thyroid a.
- Thoracic portion: Branches from the bronchial aa. & from the aorta directly
- Abdominal portion: Esophageal branch of the left gastric a.
How is venous drainage of the esophagus accomplished? What kind of venous systems do the veins drain to?
- Esophageal submucosal veins are drained by venae comitantes of the arterial supply.
- These veins drain to both systemic (subclavian) and portal (azygos) venous systems
How is the stomach secured to the diaphragm? Posterior body wall? What vertebral level?
Fastened securely to the diaphragm superiorly (TV11) via the gastrophrenic ligament
inferiorly to the posterior body wall via its continuity with the retroperitoneal portion of the duodenum (LV1 - LV2)
Why is the stomach mobile? What structures allow it to be mobile?
the remainder of the stomach is only loosely secured by the omenta (greater and lesser), it is highly mobile, so much so, that when sufficiently filled may extend into the major pelvis
What are the curvatures of the stomach?
1) Greater: convex lateral border
2) Lesser: concave medial border
What are the external regions of the stomach?
1) Cardia: indefinite area around esophageal entrance
2) Fundus: portion more superior than cardia
3) Body: area between fundus and pyloric antrum
4) Pyloric portion
What 3 parts make up the pyloric portion of the stomach?
Pyloric antrum: expanded portion proximal to pyloric canal
Pyloric canal
Pylorus: thickened muscular portion forming sphincter between stomach and duodenum, located to the right of the midline at LV1 - LV2
What are the 2 notches present on the external stomach?
1) Cardiac: notch between junction of esophagus and fundus
2) Angular incisure: sharp angulation of lesser curvature at the junction of body and pyloric portion
What forms the pyloric sphincter?
Middle layer of smooth mm in the stomach wall: the inner circular layer
- the greatly thickened segment forms the pyloric sphincter
What are some prominent features of the internal mucosa of the stomach? What forms the gastric canal?
When the muscular layers are contracted the mucosa displays longitudinally oriented folds call rugae (Magenstrassen - stomach streets)
Located predominantly along the lesser curvature; forms gastric canal (temporarily visible during swallowing)
What does the anterior side of the stomach contact?
Anterior abdominal wall
Diaphragm
Left lobe of the liver
What does the superior side of the stomach contact?
diaphragm
What is the stomach bed?
Posteriorly and inferiorly, referred to as the stomach bed - area related to the stomach that directly ācradlesā it, including retroperitoneal structures behind the posterior wall of the omental bursa.
What 6 structures are found in the stomach bed?
a. Left hemidiaphragm
b. Spleen
c. Body and tail of pancreas
d. Superior pole of left kidney
e. Left suprarenal gland
f. Splenic artery
g. Transverse mesocolon
h. Left colic flexure
What is the largest single mass of lymphatic tissue in the body?
The spleen
Where is the spleen located? What mesentery is it associate with? What ribs?
Located in the left upper quadrant within the dorsal mesentery suspended between the greater curvature of the stomach and the diaphragm at ribs 9, 10, 11.