Canonical Question
GIT – Blood Supply
Master answer
Blood supply to the Gastrointestinal system
- Portal circulatory system + arterial blood flow into liver
- 1100ml of portal blood + 400ml from hepatic artery = 1500ml (30% CO)
- Oxygen consumption – 20-35% of total body needs
Arterial Supply
| Aorta | Division / Branches | Organ supplied | |||
|---|---|---|---|---|---|
| Thoracic A. | Subclavian A. | Thyrocervical trunk | Inf. Thyroid A. | Cervical Oesophagus | |
| Bronchial A. | branches | Thoracic Oesophagus | |||
| direct branches | |||||
| Abdominal Aorta / Coeliac | Inf. Phrenic A. | Abdominal Oesophagus | |||
| Anterior branches of Abdominal Aorta | COELIAC TRUNK | Lt. GASTRIC A. | |||
| Foregut (Stomach → major duodenal papilla | |||||
| SPLENIC A. | Short Gastric A.s | ||||
| Lt. Gastroepiploic A. | |||||
| COMMON HEPATIC A. | Hepatic A. Proper | Lt. Hepatic A. | |||
| Rt. Hepatic A. | |||||
| Gastroduodenal A. | Rt. Gastroepiploic A. (gastro-omental) | ||||
| Sup. Pancreatoduodenal A. | |||||
| Supraduodenal A. | |||||
| SUPERIOR MESENTERIC ARTERY | Inf. Pancreaticoduodenal A. | Midgut (Major duodenal papilla → 2/3 of transverse colon) | |||
| Jejunal and Ileal A.s | |||||
| Middle colic A. | |||||
| Rt colic A. | |||||
| Ileocolic A. | |||||
| INFERIOR MESENTERIC ARTERY | Lt colic A. | (2/3 transverse colon → rectum) | |||
| several sigmoid A.s | |||||
| Superior rectal A. | |||||
| Distal Abdominal Aorta | Internal Iliac A. | Middle Rectal A. | Rectum | ||
| Internal Pudendal A. | Inferior Rectal A. | ||||
Venous Drainage
| Organs drained | Branches / Tributaries | IVC | |||
|---|---|---|---|---|---|
| Liver | Hepatic V.s | IVC | |||
| Fundus + L greater curvature Stomach | Short gastric V.s | Splenic V | Portal Vein | Liver parenchyma → Hepatic Veins → IVC | |
| Greater curvature Stomach | Lt. gastro-omental V. | ||||
| Pancreas | Pancreatic V. | ||||
| colon | Lt. colic V. | IMV | |||
| sigmoid | Sigmoid V. | ||||
| rectum | Superior rectal V. | ||||
| Rectum, Colon | direct | ||||
| Rt greater curvature Stomach | Rt gastro-omental V. | SMV | |||
| Pancreas, duodenum | Ant sup pancreatocoduodenal V. | ||||
| Ant and Post inferior pancreaticoduodenal V.s | |||||
| Jejunum | Jejunal V. | ||||
| Ileum | Ileal V. | ||||
| Ileum, colon, cecum | Ileocolic V. | ||||
| ascending colon | Rt. colic V. | ||||
| transverse colon | Middle colic V. | ||||
| pancreas, duodenum | Post Sup pancreaticoduodenal V. | ||||
| stomach | Rt. gastric V. | ||||
| stomach | Lt. gastric V. | ||||
| gall bladder | cystic veins | ||||
| Skin of umbilical region | para-umbilical vein | ||||
Portosystemic Anastomosis
- Areas:
- Lower end of oesophagus
- Upper part of anal canal
- Umbilicus
- Retroperitoneal Bare area of liver
- The gastroesophageal junction around the cardia of the stomach-where the left gastric vein and its tributaries form a portosystemic anastomosis with tributaries to the azygos system of veins of the caval system.
- The anus-the superior rectal vein of the portal system anastomoses with the middle and inferior rectal veins of the systemic venous system.
- The anterior abdominal wall around the umbilicus-the para-umbilical veins anastomose with veins on the anterior abdominal wall.
Exam appearances
| Exam | Exact wording | Relationship | Success |
|---|---|---|---|
| 2018A Q07 | Outline the blood supply to the gastrointestinal system (arteries and veins). | historical_member | — |
| 2021A Q07 | Outline the anatomy of the blood supply (arteries and veins) of the gastrointestinal system (oesophagus to anus) | historical_member | — |