The pancreas

Parts—The pancreas has— 1-head 2-neck 3-body 4-tail The pancreas is lobulated greyish pink gland that lies in the curvature of duodenum. The pancreas is mixed gland. It has— a.An exocrine part that secretes pancreatic juice. b.An endocrine part that secretes insulin and other hormones. Location—The pancreas lies behind peritoneum in upper part of posterior abdominal wall, at back of epigastrium and left hypochondriac region. Parts—The pancreas has— 1-head 2-neck 3-body 4-tail

i. The head is located within the curvature of duodenum. – From its lower left portion, a hook-like uncinate process projects behind superior mesenteric vessels.this means that;- The uncinate process is related anteriorly to superior mesenteric vessels. a. Anterior surface in upper part is related to transverse colon, the lower part is covered with peritoneum and related to coils of jejunum. b. Posterior surface is related to - Inferior vena cava - Right renal vessels - Right crus of diaphragm - Common Bile duct (lies in a groove on posterior surface) - Abdominal aorta (behind uncinate process)

The neck is about 2.0 cm long – On right side is groove for gastroduodenal artery. – On left side and behind is beginning of portal vein by union of superior mesenteric and splenic veins. – Its anterior surface is related to omental bursa(lesser sac) separating it from first part of duodenum.

• Aorta and origin of superior mesenteric artery The body is the elongated tapering portion that lies obliquely across the posterior abdominal wall behind peritoneum. – The body is triangular in section having three surfaces—anterior, inferior, and posterior. -The anterior surface is related to the lesser sac of peritoneum and forms a part of ‘stomach bed’ (i.e. related to posterior-inferior surface of stomach). Complication of the acute pancreatitis is the formation of pseudocyst of the pancreas and if the size of this pseudocyst is more than 6 cm the cyst can be drained through the posterior wall of the stomach by open or laparoscopic surgery -The posterior surface is devoid of peritoneum and is related to the structures in upper part of posterior abdominal wall: • Aorta and origin of superior mesenteric artery • Left crus of diaphragm • Part of left kidney and left suprarenal • Left renal vessels • Splenic vein (lies closely attached to the posterior surface)

The tail of pancreas reaches the lateral end of hilum of spleen. – The tail contains maximum concentration of islets of Langerhans. In operation of splenectomy care is taken to preserve the tail of pancreas while ligating the splenic vessels.

The Pancreatic Ducts a. The main pancreatic duct (Wirsung’s duct)courses through the pancreas from left to the right. –It lies nearer posterior surface –the main duct joins with the common bile duct to form the hepato-pancreatic ampulla(ampulla of vater). b. The accessory pancreatic duct (Santorini’s duct) remains in the head of pancreas only.The duct may end blindly, or may open,in the duodenum separately at minor duodenal papilla, situated proximal to the major duodenal papilla.

– The lymphatic drainage of pancreas. The blood supply – The arteries 1. The superior pancreatico-duodenal artery—a branch of gastroduodenal artery. 2. The inferior pancreatico-duodenal artery—a branch of superior mesenteric artery. These two arteries divided into two branches—anterior and posterior—that run between concavity of duodenum and head of pancreas, anastomosing with each other. 3. The pancreatic branches of splenic artery supply the body of pancreas.One large arteria pancreatica magna from the splenic artery is given near the tail. –The veins of pancreas drain into portal vein, superior mesenteric vein and the splenic vein. – The lymphatic drainage of pancreas. The lymphatics from the pancreas drain mainly in the pancreatico-splenic nodes.Some lymphatics from head of pancreas end in superior mesenteric and pyloric nodes.

Endocrine Pancreas There are nearly 1 million islets of Langerhans in the normal adult pancreas. Most islets contain 3000 to 4000 cells of five major types: 1-alpha cells that secrete glucagon, Opposite effects of insulin; increased hepatic glycogenolysis and gluconeogenesis 2- β-cells that secrete insulin, Decreased gluconeogenesis, glycogenolysis, fatty acid breakdown, and ketogenesis,Increased glycogenesis, protein synthesis, and glucose uptake 3-delta cells that secrete somatostatin, Inhibits GI secretion 4-epsilon cells that secrete ghrelin ;Decreases insulin release and insulin action 5-PP cells that secrete PP

Tumour of the head of the pancreas lead to obstructive jaundice

THE JEJUNUM AND THE ILEUM The jejunum and ileum constitute the large part of small intestine extending from duodeno-jejunal flexure up to junction of cecum and ascending colon • Length about 6 metres (20 feet) – The jejunum constitutes proximal two-fifth part (nearly 8 feet) – The ileum constitutes distal three-fifth part (nearly 12 feet)

The mesentery The jejunum and ileum are completely covered by peritoneum, and are suspended by a large peritoneal fold—the mesentery—from the posterior abdominal wall. – The root (attachment) of mesentery is oblique and extends from duodeno-jejunal flexure on the left to the ileocecal junction on the right. The root contains superior mesenteric vessels between the two layers. – The root of mesentery crosses the following structures on posterior abdominal wall • Abdominal aorta • Inferior vena cava • Right psoas major • Right ureter • Right testicular (ovarian) vessels

2-2 feets from ilicecal junction 3-2 inches in length MECKEL’S DIVERTICULUM It is a congenital diverticulum arising from the terminal ileum and it is the reminent of the vitello intestinal duct We use the role of two for the meckle diverticulum;- 1-2% in the population 2-2 feets from ilicecal junction 3-2 inches in length 4-2 types of epithelium;intestinal and gastric 5-2 years age and below is the presentation of the symptoms 6-2 types of surgery for it