Digestion Flashcards
Which pancreatic enzymes are secreted in their active form?
Amylase
Colipase
Lipase
List the enzymes secreted by the pancreas.
Amylase Colipase Lipase Chymotryspinogen Trypsinogen Carboxypeptidase Elastase RNAase DNAase Cholesterol ester enzyme Bicarbonate
What is a zymogen?
A collection of pro enzymes secreted from the pancreas along with enzyme inhibitiors.
What activates trypsinogen in the duodenum?
Enterokinase
Name two endopeptidases.
Chymotrypsin
Trypsin
Pepsin
What is an endopeptidase?
A proteolytic peptidase that break the bonds of non-terminal amino acids in a peptide chain.
Describe the two molecular forms which starch can take.
Amylose - non-branched, with only alpha 1-4 glycosidic bonds
Amylopectin - branched, with the main chain connected by 1-4 bonds, and the branches connected by 1-6 branches.
Is amylose or amylopectin harder to digest and why?
Amylose - because it’s unbranched, it’s packed tighter, and it’s harder for the amylase to reach the bonds
What are the normal products of starch digestion?
Disaccharides
Oligosaccharides
What carbohydrates are digested at the brush border?
Disaccharides Oligosaccharides Sucrose Maltose Lactose
What happens to starch that isn’t digested in the small intestine?
It passes into the large intestine where it is digested by colonic bacteria.
Give a brief description of acute pancreatitis.
An acute inflammatory disease in which pancreatic enzymes digest the gland.
What are some of he possible causes of acute pancreatitis?
ALCOHOL GALL STONES Infection Trauma Certain drugs
Describe the pathological mechanism of acute pancreatitis.
The way in which it begins is unknown, but it ends in the activation of trypsin.
This activates all the other pancreatic enzymes, which start to digest the gland.
Inflammatory mediators travel here and cause a local inflammatory response.
- can be systemic response in the severe cases
Give a brief description of chorionic pancreatitis.
It’s a chronic inflammation of the pancreas - destroying both the exocrine and endocrine functions.
What are the presenting complaints of chronic pancreatitis?
Weight loss (due to malabsorption)
Diabetes mellitus
Acute abdominal pain
Steatorrhea
What are some of the symptoms of acute pancreatitis?
Sudden onset abdominal pain Nausea and vomiting Fever Hypotension Shock Multi-organ failure
What are the biochemical findings you would expect in acute pancreatitis?
Increased amylase Increase lipase Increase urea Decreased albumin Decreased calcium Increased triglycerides
What are the most common causes of chronic pancreatitis?
Alcohol abuse Repeated attacks of acute pancreatitis Hereditary Trauma Hypercalcaemia Idiopathic Tropical
What are the tests of pancreatic function?
Faecal chymotrypsin
Faecal elastase
How long does elevated serum amylase last in acute pancreatitis?
It rises within 5-8 hours of onset and lasts for roughly 4 days.
Is amylase a good test for acute pancreatitis, and why?
No - because it is low specificity It can also be a sign of - other intra-abdominal disease - DKA - renal insufficiency - tumours - drugs - salivary gland lesion
What is the what does a high serum amylase, but a low urine amylase level mean?
Macroamylasaemia
-if they are both high, then it is more likely to be acute pancreatitis
What happens to serum lipase in acute pancreatitis, and what are the benefits of measuring this over amylase?
It peaks within 24hrs and return to normal within 8-14 days
It is more specific and sensitive to acute pancreatitis than amylase measurements
