Gastro-esophageal junction
The gastro-esophageal junction (GEJ) (also known as the esophagogastric junction) is the part of the gastrointestinal tract where the esophagus and stomach are joined.
Gross anatomy
The GEJ is normally mostly intra-abdominal and is 3-4 cm in length. To some extent, the esophagus slides in and out of the abdomen during respiration and when there is elevation of intra-abdominal pressure.
Histology
It is comprised of two histologically distinct areas:
- stratified squamous epithelium (same as the esophageal folds superiorly)
- columnar epithelium (same as the gastric rugae inferiorly)
Where these two distinct areas join, there is an abrupt but non-linear change in the mucosal layer: this is called the Z-line. The non-linear, zig zagging nature of the Z-line explains that the GEJ can be several centimeters in length, while the histological transition from esophageal folds to gastric rugae is abrupt.
Related Radiopaedia articles
Anatomy: Abdominopelvic
- skeleton of the abdomen and pelvis
- muscles of the abdomen and pelvis
- spaces of the abdomen and pelvis
- anterior abdominal wall
- posterior abdominal wall
- abdominal cavity
- pelvic cavity
- perineum
- abdominal and pelvic viscera
- gastrointestinal tract
- spleen
- hepatobiliary system
-
endocrine system
-
adrenal gland
- adrenal vessels
- chromaffin cells
- variants
- pancreas
- organs of Zuckerkandl
-
adrenal gland
-
urinary system
-
kidney
- renal pelvis
- renal sinus
- avascular plane of Brodel
-
variants
- number
- fusion
- location
- shape
- ureter
- urinary bladder
- urethra
- embryology
-
kidney
- male reproductive system
-
female reproductive system
- vulva
- vagina
- uterus
- Fallopian tubes
- ovaries
- broad ligament (mnemonic)
- variant anatomy
- embryology
- blood supply of the abdomen and pelvis
- arteries
-
abdominal aorta
- inferior phrenic artery
- celiac artery
- superior mesenteric artery
- middle suprarenal artery
- renal artery (variant anatomy)
- gonadal artery (ovarian artery | testicular artery)
- inferior mesenteric artery
- lumbar arteries
- median sacral artery
-
common iliac artery
- external iliac artery
-
internal iliac artery (mnemonic)
- anterior division
- posterior division (mnemonic)
- variant anatomy
-
abdominal aorta
- portal venous system
- veins
- anastomoses
- arterioarterial anastomoses
- portal-systemic venous collateral pathways
- watershed areas
- arteries
- lymphatics
- innervation of the abdomen and pelvis
- lumbar plexus
-
sacral plexus
- lumbosacral trunk
- sciatic nerve
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- perforating cutaneous nerve
- posterior femoral cutaneous nerve
- parasympathetic pelvic splanchnic nerves
- pudendal nerve
- nerve to quadratus femoris and inferior gemellus muscles
- nerve to internal obturator and superior gemellus muscles
