Gi Anatomy Flashcards
What is the position of the appendix
Posteromedial surface of the caecum
What supplies the ascending colon
Superior mesenteric art
What does the inferior mesenteric art supply
The rest of the transverse colon the descending and rectum
What are the the anal columns
The last portion of the rectum , the anal canal contains small longitudinal folds called anal columns . Oh the distal end of the anal column the columnar epithelium becomes stratified squamous epithelium
What epithelium is at the anus
Keratinised epidermis
What kind of muscle is the internal anal sphincter
Smooth muscle - involuntary
The external anal sphincter is what muscle
Skeletal muscle and is voluntary control
What epithelium is in the small intestine
Simple columnar epithelium
Describe large intestine
Walls much thinner than small intestine
No villi
Many goblet cells
Mucosa does not produce enzymes
What type of movement is in the large intestine
Segmentation contraction
Mass action contractions also called mass movement
What stimulates CFTR
The presence of bacteria in the intestine stimulates CFTR . Enterotoxins are released by bacteria and activate intracellular c AMP / protein kinase A and signal CFTR on apical surface .
Receptor is easily affected by drugs due to being in the cAMP pathway
How is chloride absorbed into cell?
Via chloride - bicarbonate anitporter
How does potassium move between cells
Passively moves along the conc gradient set up by absorption of water
Where is CFTR present
Intestine , pancreatic ducts and lungs
What vitamins are not absorbed by guy without influence of bile
Vit A D E K
Characteristics of proximal colon
Fermentation chamber
Absorption
Vagal/ pelvic and splanchic /lumbar
Superior mesenteric art
Absorptive mechanism? - 95% Cl dependent
Luminal character- active bacterial metabolism
- carb fermentation
- h2 production
Increased short chain fatty acids
Distal colon characteristics
- storage
- absorption
- pelvic / lumbar
- inferior mesenteric art
- chlorine dependent
Semisolid
PH 7
Less bacterial activity
Amino acid fermentation
Methane production
Why does upper gut have low pop of bacteria
Gastric activity
Propulsive motility
Pancreatic enzymes
Definition of diarrhoea
Increase in volume of stool or frequency if defacation
Change of vowel habit
What is dysentery
A painful , bloody , low volume diarrhoea
What’s osmotic diarrhoea
An increase in the number of osmotic particles in the lumen .
Both the electrolytes and absorbed nutrients (sugar and amino acids ) contribute to osmosis . If the absorption of either of these is reduced like in protein losing enteropathy , osmotic diarrhoea will occur
Secretory diarrhoea ?
Mature cells near the tips of the small intestinal Villi are responsible for absorption . They r stimulated to increase rate of secretion by a number of factors (ach 5HT ) to cause increase in intracellular calcium . Increase in active secretions , decrease in absorption
Inflammatory diarrhoea
Expiration of mucus , blood , protein from sites of active inflammation into the bowel lumen . Due to damage of the intestinal mucosa resulting in the loss of blood and fluid - crohns
What is ecg evidence of hyperkalaemia
Tall peaked T wave
Loss of p wave
Widened QRS with tall T wave
Rotavirus?
Virus replicates in intestinal epithelial cells - infected cells are damaged leaving immature cells with reduced absorptive capacity for sugar water and salts - so there is fluid accumulation in the lumen
Hypokalaemia on ecg
Slightly peaked p wave
St depression
Prominent u wave
Shallow t wave
Does alkalosis cause hypokalaemia or hyper
Hypo
Acidosis causes hypo or hyper kalaemia
Hyper
