Anatomy
Abdomen
A 75 year old man presents to ED complaining of abdominal pain radiating to his back, anorexia and weight loss. Imaging shows a large tumour of the neck of the pancreas. Which of the following structures is most likely compressed by the tumour:
Answer:
The portal vein is formed from the union of the superior mesenteric and splenic veins posterior to the neck of the pancreas and would most likely be compressed by a tumour at this location.Pancreas
Anatomy / Abdomen / Pancreas and Spleen
Last Updated: 11th April 2019
Anatomical Position
The pancreas lies mostly posterior to the stomach. It extends across the posterior abdominal wall from the duodenum on the right, to the spleen on the left. It lies in the epigastric region and left hypochondrium. The pancreas is a retroperitoneal organ (except for a small part of its tail) and consists of a head, uncinate process, neck, body and tail.
Surface Markings of the Pancreas. (Image by Henry Vandyke Carter [Public domain], via Wikimedia Commons)
Relations
- The head of the pancreas lies within the C-shaped concavity of the duodenum. The head is related anteriorly to the first part of the duodenum, the transverse colon and coils of jejunum and posteriorly to the common bile duct and the inferior vena cava and the termination of the renal veins.
- The uncinate process projects from the lower part of the head and passes posterior to the superior mesenteric vessels.
- The neck is anterior to the superior mesenteric vessels. Posterior to the neck of the pancreas, the superior mesenteric and splenic veins join to form the portal vein.
- The body is elongated and extends from the neck to the tail of the pancreas in the transpyloric plane (at the level of vertebra L1) to lie behind the stomach and to the left of the superior mesenteric vessels.
- The intraperitoneal tail passes between layers of the splenorenal ligament. It is related to the left kidney posteriorly, the hilum of the spleen laterally, the left colic flexure inferiorly and the stomach anteriorly.
![Modified by FRCEM Success. Original by Henry Vandyke Carter [Public domain], via Wikimedia Commons](https://primary-cdn.frcemsuccess.com/wp-content/uploads/2017/02/Pancreas2.jpg)
Relations of the Pancreas. (Image modified by FRCEM Success. Original by Henry Vandyke Carter [Public domain], via Wikimedia Commons)
Pancreatic Duct
The pancreatic duct begins in the tail of the pancreas and passes to the right, through the body and to the head where it turns inferiorly and joins the bile duct forming the hepatopancreatic ampulla (ampulla of Vater) which enters the second part of the duodenum at the major duodenal papilla. The accessory pancreatic duct empties into the duodenum just above the major duodenal papilla at the minor duodenal papilla.
![Modified by FRCEM Success. Original by Henry Vandyke Carter [Public domain], via Wikimedia Commons](https://mrcemsuccess.com/wp-content/uploads/2017/02/Pancreas3.png)
Pancreatic Duct. (Image modified by FRCEM Success. Original by Henry Vandyke Carter [Public domain], via Wikimedia Commons)
Blood supply
The arterial supply to the pancreas is primarily derived from the splenic artery from the coeliac trunk, assisted by branches from the gastroduodenal artery (from the common hepatic artery from the coeliac trunk), and from the superior mesenteric artery.
Venous drainage of the head of the pancreas is via pancreaticoduodenal veins into the superior mesenteric vein and portal vein. Venous drainage of the body and tail of the pancreas is via pancreatic veins into the splenic vein.
Lymphatics
Lymphatics draining the pancreas empty into the pancreaticosplenic nodes and the pyloric nodes, which in turn drain into the superior mesenteric and celiac pre-aortic lymph nodes.
Innervation
Visceral afferent fibres travel in the greater and lesser splanchnic nerves. The segmental level of innervation is T6 - T10. Pain typically radiates to the middle of the back due to irritation of the parietal peritoneum covering the pancreas.
Report A Problem
Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.
Loading Form...
- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
