Flashcards in Week 4 Deck (58)
What is the gastroileal reflex stimulated by and what does it involve?
Stimulated by gastric distension
Involves opening of the ileocaecal valve
What is absorbed and secreted by the large intestine?
Water, sodium and chloride ions are absorbed
Potassium, bicarbonate and mucus are secreted
Carbohydrates not absorbed in the S.I can be absorbed in the L.I but first must be converted. What does this involve?
Colonic flora ferment the carbohydrates to short-chain fatty acids which can then be absorbed
Is the internal anal sphincter under control of the brain or the spinal cord?
What does RELAXATION of the skeletal muscle of the external anal sphincter cause?
What does CONTRACTION of the skeletal muscle of the external anal sphincter cause?
What are some of the roles of colonic bacteria within the bowel?
Increase intestinal immunity
Activate some drugs
Synthesis vitamin K2 and free fatty acids
What are the two main important drug classes used for IBD?
Steroids and immunosuppressants
What two conditions fall under IBD?
Crohn's Disease and Ulcerative Colitis
What is a polyp?
A protrusion above an epithelial surface
What is an adenoma?
Benign tumours composed of epithelial cells
What is an adenocarcinoma?
A malignant epithelial tumour
Injecting what substance can prevent bleeding when removing a polyp?
Why must all adenomas be removed?
They are dysplastic and are pre-malignant - it would only take a few more mutations for a cancer to develop and thus they need to be removed to prevent this from happening
Are left or right sided colorectal cancers more common?
Why can there be spread to the liver from a colorectal cancer?
The merging of the systemic with the portal venous system allows metastasis to be directed towards the liver
Name two types of inherited cancer syndromes
HNPCC (hereditary non polyposis coli)
FAP (familial adenomatous polyposis)
What are causes of diverticular disease?
Low fibre diet
Increased intraluminal pressure
What is diverticulitis?
Inflammation of the diverticulae
What are some of the complications of diverticular disease?
Rupture/ Perforation - peritonitis/ sepsis
What is the most common fistula that can occur from the large intestine? What can this cause?
Colovesical fistula (bladder and L.I communicate)
- Can cause recurrent UTI's and flatus (bubbles) in the urine
What is a fistula?
A pathological communication between two epithelial surfaces
What classification is used to stage acute diverticulitis?
What is the name of the surgery used in the management of complex diverticulitis?
Who gets ischaemic colitis?
Arteriopaths (patients with artery disease)
What are some of the causes of rectal bleeding?
What are some of the possible causes of large bowel obstruction?
What are the symptoms of large bowel obstruction?
What is a sigmoid volvulus?
When the sigmoid colon twists on its mesentery causing the lumen to be blocked off and the vasculature to be pinched off - can cause infarction and gangrene