1. GIT intro Flashcards
What is the distance from the incisor teeth to the Oesophago-gastric junction?
38-40cm
How long is the oesophagus?
25cm
What is Barrett’s Oesophagus?
An adaptive feature replacing normal stratified squamous epithelia of oesophagus with metaplastic columnar epithelia (with goblet cells) anywhere in the oesophagus (usually by LES).
Caused by chronic reflux of acid stomach contents
2 possible types of cancer that can arise in the oesophagus
Squamous cell carcinoma
Adenocarcinoma (if metaplastic columnar epithelia present)
Things that may cause dysphagia
Difficulty coordinating swallowing (e.g. Bulbar Palsy; bilateral probs with cranial nerves)
Narrowing of food pathway, which can be malignant
Benign narrowing of food pathway (e.g. Fibrous rings)
Achalasia (failure to relax LOS)
What are oesophageal varices?
Dilated mucosal veins in oesophagus that can bleed torrentially
Formed following portal hypertension as result of porto-systemic anastomosis
Mechanisms which help prevent stomach contents refluxing into oesophagus
Mucosal folds at end of oesophagus
Acute angle that oesophagus joins stomach
Higher abdominal pressure than thoracic pressure
Right crus of diaphragm acts like sling around oesophagus
Name/label the regions if the stomach
http://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Regions_of_stomach.svg/2000px-Regions_of_stomach.svg.png
Cardia Fundus Body Pylorus (Lesser & greater curve)
Define peptic ulceration
Damage occurs & extends through muscularis mucosa layer of stomach or duodenum
Which part of the duodenum is prone to ulceration & why?
First part
Receives acidic Chyme from stomach before neutralised by various secretions which only enter duodenum in 2nd part
If a peptic ulcer erodes posteriorly through the 1st part of the duodenum, what structure might be damaged?
Gastro-duodenal artery
May result in haemorrhage, haematemesis & malaena
What is delivered through the second part of the duodenum?
Secretions from the gallbladder & exocrine pancreas (bile, pancreatic enzymes, neutralising juices)
Where does fluid entering the GIT come from?
Food, water, gastric secretions, alkali
What changes would there be in faeces if the small intestine was removed?
Watery stool
Fatty stool
Small intestine is the major site of water & fat absorption
2 conditions that affect small intestine & potentially result in malabsorption
Crohn’s Disease
Coeliac disease
What is a Meckel’s Diverticulum
Vestigial remnant of the vitello-intestinal duct, following a diverticulum which usually follows a rule of two’s
(2ft from ileo-caecal valve, 2in long, affects 2% of pop)
What might be the clinical presentation of someone with acutely blocked small intestine?
Abdominal pain (colicky: comes & goes)
Abdominal distension
Vomiting
2 common causes of Appendicitis
Lymphoid hyperplasia (lymphoid tissue around base if appendix occuludes opening, causing inflammation)
Faecolith
In Appendicitis, where does pain start and then move to?
Starts as vague peri-umbilical pain
Moves to right iliac fossa
What are diverticula & where do they develop?
Small mucosal herniations, which protrude through intestinal layers
Most common in sigmoid colon
Where is the Dentate (Pectinate line) & what epithelia is present in each?
Junction in anal canal that divides hindgut from Procto-deum
Different embryological derivatives & so different epithelia, blood supply & nerve innervation
Epithelia above = columnar
Epithelia below = stratified squamous
What type of cancer may occur above & below the Dentate line
Above: adenocarcinomas (columnar epithelium)
Below: squamous cell carcinoma
What are haemorrhoids?
What are the symptoms of troublesome haemorrhoids?
Swelling of haemorrhoidal venous cushions (vascular structures supporting anal continence), distending beyond normal limits
Pathological when start to cause symptoms:
Pain, itching, bleeding, prolapse
Which structures are retroperitoneal?
Mnemonic: SAD PUCKER
Suprarenal (adrenal) gland Aorta / IVC Duodenum Pancreas Ureters Colon (ascending & descending) Kidneys E(o)esophagus Rectum
