The Tube Flashcards
What is digestion?
breakdown of macromolecules and nutrients intake
Meckel’s Diverticulum
Remnant of the connection between the developing gut and the embryonic yolk sac
During embryogenesis, the tube should regress by apoptosis. If not, it can fill with material due to peristalsis and result in inflammation (this will generally require surgery)
Acquired Diverticulum of the Colon
Increases in incidence with age
Can occur from chronically low fibre diet
How does the contents of the Small Intestine differ from the Large Intestine?
SI - contains chyme, acid is neutralised and nutrient is absorbed
LI - Becomes more faece-like as it heads to the rectum (more time, more dehydrated and compact)
Fistulas, Adhesions and Abcess consequences
Loose stool:
- Can occur from less fibre, high fat diet
- Muscle contract harder, longitudinal and circular muscle layers hypertrophy. Epithelial lining between the the hypertrophied muscle layers can then balloon. This can result in the formation of Granulation Tissue and predispose individual to adhesions and result in fistulas
What is a Fistula?
Abnormal communications between organs
What is an ulcer
localised area of necrosis on the mucous membrane
Explain metabolism
Liver converts nutrients into energy or a storage form
What is required for the digestion, absorption and metabolism of fat?
Bile is needed from the liver to emulsify the fat
Pancreatic lipase can work more effectively and break down fat
Travels across the wall of SI and goes to liver for metabolism
What is required for the digestion, absorption and metabolism of Protein?
Protein is broken down into large polypeptides in the stomach by pepsin
Large Polypeptides are broken down into small polypeptides and small peptides, in the small intestine, by pancreatic enzymes
Small polypeptides/peptides are broken down by brush border enzymes in the small intestine into amino acids
Amino acids then go to the liver for metabolism
What is required for the digestion, absorption and metabolism of carbohydrates
Pancreas produces important digestive enzymes such as salivary amylase
Salivary amylase and pancreatic amylase assist in breaking down starch and dissacharides
Brush border enzymes assist in the breakdown of disaccharides such as lactose, maltose and sucrose. Results in monosachrides sich as galactose, glucose and fructose
Monosaccharides are then absorbed across the wall and travel through the apical layer of epithelial cells before passing through the basal membrane to enter the blood.
The blood then drains to the liver for metabolism
What is the pathogenesis for the development of the cancers of the small and large intestine
- Very common to become malignanat
- Polyps contains cells that are genetically unstable and are prone to more muations
Normal tissue - multiple mutations - benign - further mutation - cancer
What are the risk factors for the development of cancers of the tube and accessory organs?
Smoking
Alcohol
Chronic inflammation and gastritis (risk factor for gastric cancer),
CIBD (risk factor for bowel cancer),
Cirrhosis of liver (risk factor for liver cancer)
Hepatopancreatis (risk factor for hepatic cancer)
Genetics, low fibre, high fat and refined carbohydrate diet and inflammatory bowel disease
What are the possible consequences of chronic gastritis?
Cancer
Healing of ulcer with base a of granulation tissue can increase risk of obstruction
Bleeding
- Eroding through small vessels can result in anaemia
- eroding through major vessel can result in death due to blood loss,
- perfusion and will result in shock
Risk Factors for the development of gall stones and some of the possible consequences of having them
5F’s
Rapid weight loss
One stone predisposes you to more stones, obstruction to bile flow can csause cirrohsis of the lliver
Chronic pancreatitis increases risk for pancreas cancer
