Case 1 - The Pancreas

Front 1

Gross Anatomy

Back 1

Most retroperitoneal structure.
Lies on posterior abdominal wall, anterior to left kidney, posterior to stomach.
Mixed endocrine-exocrine gland.

Front 2

Exocrine: Gross Anatomy

Back 2

Exocrine tissues release pancreatic juice.
Pancreatic juice is transported to the duodenum via:
- the pancreatic duct,
-Ampulla of Vater/ major duodenal papilla.
-sphincter of oddi.

Front 3

Classification of Exocrine Glands:
For all exocrine glands.

Back 3

-Derived from epithelial tissue
-Connected to epithelial surface through ducts.
-Classified on basis of structure.
Unicellular/multicellular

Front 4

Multicellular Exocrine Glands

Back 4

-Tubular Glands (cells lie along ducts)
-Acinar glands (cells in sac at end of duct)
-Compound tubulo-acinar. (submandibular)

Front 5

Histology

Back 5

-Exocrine glands are compound acinar.
-Pancreatic enzymes are secreted in the acinus, as inactive enzyme precursors.
-Ionic composition of pancreatic juice is modified in the ducts by centroacinar cells.
-Ducts drain into pancreatic duct.

Front 6

Acinar Defect in CF

Back 6

Misfunction in CFTR.
Less transport of Cl-, leads to less Na+ following. Less salt transport means less water and less fluid secretion.
Bicarbonate replaces Cl- movement in attempt to maintain secretion.

Front 7

Fluid and Bicarb secretion

Back 7

Acini
- Not as vascularised as in salivary glands
-NaCl secretion
-Isotonic
Ducts
-Secrete largest volume of fluid
-HCO3- secretion
-CFTR Cl- channels and Cl-/HCO3- exchange
-Isotonic.

Front 8

Protein Secretion

Back 8

Amylase
-Carbohydrate Digestion
Lipase, Phospholipase
-Fat Digestion
DNAse, RNAse
-Nucleic acid digestion.
Trypsin, chymotrypsin, elastase.
-Protein Digestion

Front 9

Pancreatic Proteases

Back 9

-Secreted as precurors.
-Activation by enterokinase and trypsin in the intestine.
-Many different proteases
-Further protein digestion by intestinal peptidases.
*Brush-border membrane and cytosolic.

Front 10

Control of Pancreatic Secretion
Cephalic and Gastric Phase

Back 10

-Vagus (ACh) stimulates short term acinar and some ductal secretion.
-25% secretory response via vagus.
-Gastrin (weak - via CCKa receptors)

Front 11

Control of Pancreatic Secretion
Intestinal Phase

Back 11

-Vagus Nerve
-Hormones - strong stimuli
*secretin
*cholecystokinin-pancreozymin (CCK-PZ)
-at least 60% of all pancreatic secretion is driven by endocrine factors in intestinal phase

Front 12

Blood Supply of the Pancreas

Back 12

-Coeliac and SMA arteries
-Hepatic Portal Vein.

Front 13

Nerve Supply of the Pancreas

Back 13

-Vagus Nerve
-Splanchnic sympathetic nerves.

Front 14

Exocrine drainage

Back 14

-Pancreatic Duct
-joins common bile duct
-opens into the duodenum via Ampulla of Vater

Front 15

Exocrine Arrangement

Back 15

-lobules composed of acini.
-spherical acini

Front 16

Endocrine arrangement

Back 16

10p6 pancreatic islets.
-not connected to exocrine arrangement.
-B cells -secret insulin
-a cells that secrete glucagon.
-D cells synthesize somatostatin.

Front 17

Pancreatic Enzymes

Back 17

-Trypsinogen
-chymotrypsinogen.
-procarbxypeptidases
-pro-elastase
-phospholipase A
-pancreatic lipase
-pancreatic amylase.
-ribonucleases
-deoxyribonucleases

Front 18

Pancreatic Stimulation

Back 18

-Cholecystokinin (released when food enters the duodenum)
-Secretin (enhances the effects of CCK)

Front 19

CFTR alkaline fluid

Back 19

Bicarb solution buffers acidic gastric contents.
Centroacinar and duct cells secrete fluid and alkali, by exchanging Cl- for HCO3-.

Front 20

Common Disorders

Back 20

Pancreatic Exocrine insufficiency:
dairrhoea, steatorrhoea, weight loss and nutritional deficiencies.

Acute Pancreatitis - potentially life threatening - serum lipase or amylase levels high.

Chronic Pancreatitis - may follow repeated bouts of acute pancreatitis

Pancreatic adenocarcinoma/ neuroendocrine tumour