Digestive system II Flashcards
general features: stomach
- lesser and greature curvatures
- cardia, fundus, body, pylorus (pyloric antrum, pyloric canal)
stomach: layers
- rugae: longitudinal folds
- simple columnar epithelium: secretes alkaline mucus, gastric pits, glands
- muscularis: extra oblique layer
list stomach gland cells:
- mucous neck cels
- chief cells
- parietal cells
- enteroendocrine
stomach gland cells: function
- mucous neck: secrete mucous
- chief: pepsinogen (pre: pepsin, gastric)
- parietal: HCl, intrinsic factor
- enteroendocrine: hormones (seretonin, gastrin, somatostatin)
stomach secretions:
mucous, HCl, intrinsic factor, gastric lipase, pepsinogen, gastrin
stomach mechanical digestion: features
peristaltic movement: mixing waves, chemical digestion, some absorption (H2O, fatty acids, some drugs)
peptic disease: eg
- injury to wall of stomach
- helio bacterium invades wall and eats through
- can cause death
blood supply: stomach
from celiac trunk,
- R/L gastric
- R/L gastroepiploic
- short, posterior gastric artery
veins: accompanying into IVC
innervation: stomach
- vagus: parasympathetic fibres
- sympathetic nerve from celiac ganglia
pancreas: features, ducts, retro/intraperitoneal?
retroperitoneal
- pancreatic juices (water, salts, sodium bicarb, enzymes, loose ct, capsule, septa
ducts:
- main pancreatic duct, joins common bile duct (liver) 0> hepatopanceatic ampulla
- accessory pancreatic ducts
pancreas: secretions, glands
- pancreatic acinar cells
- proteases, lipases, amylase, phospholipase A2, nucleases
- alkaline secretion, neutralises stomach contents
- hormones from enteroendrocrine cells of mucosa in acidic response to acidic chyme -> duodenum
blood supply: pancreas
- splenic artery
- pancreaticduodenal artery,
- superior mesenteric artery,
liver: function
- metabolism
- detoxification
- bile (yellow-brown, green for water, salts, cholesterol, lecithin, pigment, ions emulsify fat
- storage
- phagocytosis
- activate Vitamin D
liver: location in regions
L -> R hypochondriac
- epigastric
- covered in dense irregular dense irregular
features: liver
- diaphragmatic, visceral surface
- lobes: R, L, caudate (inferior)
- falciform, R. L umbilical ligament R, L coronary
hilum: porta hepatis
- on visceral surface, vessels, hepatic nerve plexus, lymphatics, hepatic ducts
blood supply: liver
dual blood supply:
- hepatic portal vein (deoxygenated, nutrients and other materials from GIT)
- hepatic artery (oxygenated)
venous/ innervation: liver
- venous drainage (R,L and middle hepatic veins-> IVC)
- innervated: vagus (parasympathetic, sympathetic from greater splanchnic nerves) through celiac ganglia
features: liver (hepatic) lobule- hepatocytes, hepatic sinusoids
- portal spaces at periphery, vein in centre
- hepatocytes: lrg cuboidal -> laminae (liver plates)
- hepatic sinusoids: lined with discontinuous epithelium, Kupffer cells (detect, engulf bacteria, aged erthryocytes)
features: liver (hepatic) lobule- portal space, blood flow
- portal space-> portal triads: branch of hepatic artery, portal vein, bile duct (also lymph vessels)
- blood flows: portal triad through sinusoidal channels -> central vein -> sub-lobar veins -> inf. vena cava
features: bile canaliculi
located in btw hepatocytes
- drain into bile ductules, ductules merge with bile ducts in portal spaces
features: bile flow and general
bile ductules -> bile ducts -> R,L hepatic duct-> cystic duct -> common bile duct -> duodenum
- Herring canal: drain bile
bile made in hepatocytes, collects into bile canaliculi -> stored/used in gall bladder
cirrhosis: eg
liver regeneration relatively good, but damaged over extent causes cirrhosis
features: gall bladder
pear shaped
- fundus, body, neck
- stores/ concentrates bile
- inn: celiac plexus and vagus nerve
bile used for: made up of?
water, electrolytes, bile acids, cholesterol, phospholipids, bilirubin
- bile acids: vital for digestion and absorption of fats
- waste products removed in bile (esp. cholesterol) converted to bile acids
- most bile acid reabsorbed and reused
system of ducts from liver to duodenum:
R, L hepatic duct -> common hepatic duct (liver) -> joins with cystic duct from gall bladder -> common bile duct -> joins with pancreatic duct = hepatopanceatic ampulla -> duodenum
small intestine: function and parts
- primary site of absorption (pylorus to ileocecal junction) - duodenum (c shaped)
- jejunum
- ileum
small intestine: wall layers
- 4 wall layers
- plicae circulares: mucosa, submucosa folds (x3 SA)
- vili: projections from mucosa (x10) capillaries, lacteals
- microvili: plasma membrane projections (x20)
mucosa: small intestine
- intestinal glands, crypts of Lieberkühn
- absorptive (tall col)
- goblet (mucous)
- enterendocrine (hormones)
- M cells (microfold, modified absorptive, found over lymph nodes, carry antigens to MALT)
- Paneth: antimicrobial lysosymes, base of intestinal glands
submucosa: small intestine
duodenal Brunner’s glands: alkaline mucous to neutralise acidic chyme from stomach
- MALT: prominent in small intestine- lymphocytes loose in lamina propria, and between epithelial cells
- found in mucosa, submucosa (esp ileum)
- Peyer’s patches create immune barrier
small intestine: main blood supply
- celiac trunk -> superior mesenteric artery
specialisations: duodenum
villi leaf/ ridge shaped
- Brunner’s glands
specialisations: jejunum
main absorptive site, most complex finger-like villi
specialisation: ileum
greatest development of gut-associated lymphoid
- Peyer’s patched
- leaf like villi
large intestine: features, function
- absorb water, inorganic ions, formation of fecal mass
- caecum, appendix, colon (ascending, hepatic flexure, transverse, left splenic flexure, descending) sigmoid, rectum, anal canal
- internal anal sphincter (smooth muscle), external anal sphincter (skeletal m)
feces: features
water, inorganic salts, epithelial cells, bacteria, unabsorbed digested materials, indigestible food
large intenstine: teniae coli
portions of longitudinal muscles thickened to form 3 bands
large intestine: haustra
pouches of colon
large intestine: omental appendices
pouches of visceral peritoneum (filled with fat)
surface of mucosa: large intestine
simple columnar, relatively smooth
- no plicae circulares,
- no intestinal villi
large intestine: cells
- absorptive cells (columnar with short microvilli)
- goblet cells
- Crypts of Lieberkühn (longer and straighter)
- bacteria present
diarrhoea: eg
- deprives body of water and salt -> severe dehydration
- water contaminated with feces
- bad hygiene conditions (food prep, person to person)
treatment:
- dehydration
- zinc supplements
- nutrient rich foods
blood supply: large intestine
- superior, inferior mesenteric arteries
- superior, middle, inferior rectal arteries
innervation: large intestine
sympathetic: celiac, superior and inferior mesenteric plexus
parasympathetic: vagus and pelvic splanchic nerves
features: appendix
evagination of cecum:
- abundant lymph follicles
- shorter intestinal glands, no teniae coli
list peritoneum folds:
- greater omentum
- lesser omentum
- falciform ligament
- mesentery
- mesocolon
greater omentum and lesser omentum location:
greater:
- attached to stomach and duodenum- transverse colon, covers small intestine
lesser:
- suspends stomach, duodenum from the liver
falciform and mesentery location:
f. ligament:
- liver to anterior abdominal wall and diaphragm
mesentery:
- post abdominal wall to jejunum and ileum
mesocolon location:
post abdominal wall to transverse and sigmoid colon
