glands - pancreas

Question 1

where is the pancreas

Answer 1

Positioned at the level of the transpyloric plane L1

Head is within the C shape of the duodenum

Question 2

what are the functions of the pancreas

Answer 2

Endocrine and exocrine function

Endocrine = hormones that regulate metabolism and energy storage/use

Exocrine = enzymes involved in digestion

Question 3

describe the gross structure of the pancreas

Answer 3

Divided into 5 parts

Head - attached to, and sits in the c shape of the duodenum

Uncinate process

Neck - overlies superior mesenteric vessels (they form a groove on the posterior neck)

Body - crosses body midline behind the stomach

Tail - only part of pancreas that is intraperitoneal

Has an associated pancreatic duct that unites with the common bile duct to form the ampulla of Vater that enters the duodenum via the major duodenal papilla controlled by the sphincter of Oddi

Question 4

blood supply of pancreas

Answer 4

Blood Supply: Splenic artery (coeliac trunk and superior mesenteric)

Question 5

venous drainage of pancreas

Answer 5

Venous drainage:
hepatic portal vein (head)
splenic vein (rest)

Question 6

functional unit of the endocrine pancreas

Answer 6

Functional unit are the islet of Langerhans

Question 7

what is each islet of langerhan made up of (endocrine pancreas)

Answer 7

Beta cell
Alpha cells
Delta cells
Pancreatic polypeptide cells

Each islet is supplied by 3 arterioles that branch into fenestrated capillaries

Question 8

what is the functional unit of the endocrine pancreas

Answer 8

acinar cells made up of many acini = site of synthesis, storage and secretion of enzymes

Question 9

describe the histology of the endocrine pancreas

Answer 9

Exocrine:
Made up of clusters of acini which are at the end of intercellular canaliculi = this is an acinar cell

intercalated ducts come from each acinar cell and drain into an intralobular duct

many interlobular ducts drain into interlobular ducts

Interlobular ducts drain into the main pancreatic duct to the duodenum

Question 10

describe the function of the cells in the islets of langarhans in the endocrine pancreas

Answer 10

Beta cells = secrete insulin
Alpha cells = secrete glucagon
Delta cells = secrete somatostatin

Question 11

what is diabetes mellitus type 1

Answer 11

diabetes mellitus type 1 occurs when the beta cells of the pancreas are destroyed by the immune system and thus not enough insulin is synthesised = leads to hyperglycaemia

Question 12

what is the function of the exocrine pancreas

Answer 12

Exocrine:
Pancreas produces
Lipase - enters the duodenum along with bile
Protease - for protein digestion in stomach
Amylase - breaks down starch

Question 13

what is the origin of the pancreas

Answer 13

FOREGUT - endoderm

Question 14

describe the development of the pancreas

Answer 14

Ventral bud forms from the hepatic duct
Ventral bud forms the lower head and ucinate process

Dorsal bud forms from the dorsal duodenum and extends into the dorsal mesentary
Dorsal bud forms the body, tail and upper head

Ventral and dorsal buds rotate and fuse

Question 15

describe the development of the pancreatic ducts

Answer 15

The main pancreatic duct is formed from the ventral bud duct and DISTAL part of the dorsal bud duct

The accessory pancreatic duct is derived from proximal part of the dorsal bud duct

Question 16

what is an annular pancreas

Answer 16

anular pancreas
This is a thin, flat band of pancreatic tissue that surrounds the second part of the duodenum, causing a duodenal obstruction