Large Intestines Flashcards
what are the different parts of the large intestine?
caecum, colon and rectum
what is the part of the caecum?
appendix
what are the different parts of the colon?
ascending, transverse, descending and sigmoid
what is the appendix made of?
inflammatory cells
what does the caecum do?
holds faecal material of which 60% is bacteria
what is the hepatic flexure?
a bend of the colon at the liver
what is the splenic flexure?
a bend of the colon at the spleen
what is the taenia coli?
the band of tissue running down the middle of the colon
what are haustra?
the dips in between the pouches of the colon
what are appendices epiploicae?
fatty tags that have no function and are around the taenia coli sometimes
describe the internal sphincter, what type of muscle it is made of and what function it is
cannot control it, smooth muscle, lets you know when you need to go to the toilet
describe the external sphincter and what type of muscle it is made of
under voluntary control from the age of 2 years as it does not develop when a baby is born, made of skeletal muscle
what is the ileo-caecal junction?
junction between caecum and ascending colon
what does the ileo-caecal junction do?
allows chyme to pass from small intestine to large intestine
what leads off from the caecum?
the appendix
what is the basic structure of the large intestine?
epithelium, intestinal crypts and mucosal glands
what type of epithelium is present in the large intestine?
simple columnar with goblet cells
what are the differences of large intestines to small intestines
no villi, incomplete layer of longitudinal muscle, taenia coli, ring-like arrangement of circular muscle, haustrae
what can damage to the epithelium cause?
polyps
what happens once a high grade polyp goes down to the submucosa?
it becomes cancer an it spreads
what is an intestinal crypt?
a dip in the epithelium
why do the large intestines have so many goblet cells?
because faecal material is being made
what is the function of the colon?
absorption
what does the colon absorb?
fluid and electrolytes from the small intestine chyme
what does failure to reabsorb result in?
diarrhoea
what are the roles of intestinal flora?
ferment dietary fibre and lipid, gases produced, synthesise some vitamins (vitamin B and K)
what are abscesses typically caused by?
anaerobic bacteria
how can antibiotics cause diarrhoea
they change the gut flora
what does vitamin B12 do?
makes sure the nerves are working properly
what does vitamin K do?
it is essential for blood clotting
where is the main places that the large intestine squeezes chyme
the caecum and ascending colon
what are the movements like in large intestine motility?
propulsive and mixing
what is the function of peristalsis in the large intestin
it propels semi-solid faecal matter towards rectum
where does short range peristalsis take place?
the transverse and descending colon
what do mass movements do?
move chyme/faces from proximal colon to distal colon
when do mass movements take place?
after meals
what happens to chyme once the water gets taken out?
it becomes faeces
what is the rectum and internal anal sphincter controlled by?
the autonomic nervous system
what happens in an ileostomy?
the problem area is taken out and the ileum is brought out onto the surface (now called stoma)
what happens in a colostomy
bring colon out onto abdominal wall which can be reversed depending on the condition
what is diarrhoea
failure of fluid absorption
what does diarrhoea result in?
dehydration and electrolyte imbalance
what is diarrhoea mainly caused by?
G.I.T infections
what is constipation due to?
increased fluid absorption and can be a side effect of some drugs e.g. opiates
