Flashcards in Alimentary System Deck (598)
What is digestion?
Break down of macromolecules to allow absorption (physical or enzymatic)
What is absorption?
Moving nutrient and water across a membrane
What are the components of the GI tract?
Liver (gall bladder)
What are the names of the salivary glands?
What are the general symptoms of GI disease?
What is koilnychia?
Spooning of the nails
What is leuconychia?
Whitening of the nails
What is the biggest cause of disease in UK from a GI disease?
What proportion of hospital admissions are due to GI disease?
What are the major GI diseases worldwide?
2) Enteric infections
3) Viral hepatitis and consequences
4) Gastric cancer
What are the major GI diseases in the UK?
1) Dyspepsia (indigestion)
2) Liver disease (due to alcohol and obesity)
3) Colon cancer
What are the main causes of abnormal liver function tests in the UK?
1) Chronic Hep B
2) Chronic Hep C
3) Alcohol-related steato-hepatitis
4) Obesity-related steato-hepatitis
What is Barrett's oesophagus?
Where the squamous-cell epithelium of the oesophagus mucosa is replaced by metastatic columnar cells
What is the prevalence of gall stones? Who is most likely to suffer?
Middle-ages overweight women
What is the main cause of chronic pancreatitis?
What is normally present in acute pancreatitis?
Ethanol accumulation and gallstones
How many people are affected by IBS?
What is the basic structure of the gut wall?
- Lamina propria
- Muscularis mucosae
- Serosa / Adventitia
What is the lamina propria and what is contained in this layer?
Connective tissue containing capillaries, nerve endings etc
What are the submucosa and muscularis and what is contained in these layers?
Submucosa: Connective tissue
Muscularis: Smooth muscle
Both contain nerve plexus
What spinal levels does the oesophagus start and pass through the diaphragm?
What nerves are at risk during oesophageal surgery?
Recurrent laryngeal nerve
What epithelia make up the oesophagus lining?
Stratified squamous epithelia
What sphincters are present in the oesophagus and where are they? When are they open?
Upper oesophageal sphincter at the top
Lower oesophageal sphincter near the stomach
Permanently closed. Opened by the brain by active swallowing.
Upper closes as soon as food passes
Lower open for the whole duration of swallowing
What type of muscle is the upper oesophageal sphincter
What type of muscle is the lower oesophageal sphincter
Skeletal and smooth muscle
How does the peristalsis wave move food down the oesophagus?
Muscle above the food bolus is contracting and the muscle below is relaxing which pushes the food down the oesophagus.
Can have secondary wave if food does not pass down the first time
GRAVITY HAS NO IMPACT!
What is the gastro-oesophageal junction? How is acid reflux prevented at this point
The point where the oesophagus joins the stomach. Once swallowing reflex has passed the skeletal muscle of the diaphragm, the circular muscle of the lower oesophagus closes so food can't pass back into the oesophagus. This is helped by the fact that the stomach is below the diaphragm so the pressure either side of the sphincter is equal. Less likely to get reflux
(Negative pressure above the diaphragm)
Why do you get bad acid reflux when pregnant?
Pushes stomach up so oesophagus only above the diaphragm where there is negative pressure. Pressure difference either side of the sphincter means acid reflux is more likely