digestive system Flashcards
what are 6 processes in digestive system
ingestion propulsion chemical digestion absorption mechanical digestion defecation
what controls muscle movement
brain
what is leaky gut
not selective, alcohol can promote so epithelial cells become leaky
mouth
mastication
larger sensory input
some food absorbed
tongue - mechanical digestion
saliva
- composed of mucous, lysosomes, antibodies, inorganic ions , amylase
- contain alpha amylase and amyloclucosidase
- contain 4 glands: parotid,intrinsic, sublingual and submandibular
throat
voluntary swallowing response
pharynx- tube shared by repiratory system and digestive system
larynx- respiration system , blocked duding chocking
epiglottis- blocks larynx during swallowing
oesophagus
involuntary contraction aid perestalsis ( wave like muscle contractions )
what is chyme
small particles of food and gastric juice
stomach
pyloric sphincters slowly release chyme into duodenum ( gastric emptying)
name gastric glands in stomach
chief cells - secret pepsinogen
parietal cells- secret HCL, helps to activate pepsin
what is the role of endocrine cells
release gastric hormones when sense the arrival of food into stomach ( protein)
induce release of HCL. > release of pepsinogen > release of mucous
what are the role of HCL
- denaturation of protein
- inactivation of microorganism
- activation of pepsinogen> pepsin
- liberation of ferric ion from food
- gastric absorption of water, alcohol, drugs in hepatic portal vein
tell appetite hormone
gherlin released by stomach
example of + feedback mech
gastrin ( hormone) produced by stomach lining induces more secretion of HCL and pepsinogen
CCKstimulated release of bile and pancreatin enzymes
example of - feedback mech
CCK - slow down gastric emptying ( inhibition)
by which cells, hormones are released when food reached duodenum
by enteroendocrin cells
- CCK, secretin
CCK
inhibit gastric emptying
released in response of fat presence
driggers contraction of the gall bladder
stimulate secretion of bile and enzymes
secretin
released in response to acid
inhibit gastric emptying
cause release of sodium bicarbonate
secretion of pancreatic enzymes
pancreatic enzymes
produce by pancreases delivered to duodenum via pancreatic duct
involved in: protein, lipid and carbs digestion
what is cystic fibrosis
over production of mucus which blocks vessels, ducts> problems with micronutrient digestion> low energy
Solution: take supplements containing enzymes which will break monosaccharide in mouth
describe enterocyte
specialised epithelial cell
has microvilli - facing lumen ( protrusions)
has transmembrane enzymes - digestion
has baselateral membrane - facing connecting tissue
villi made from enterocyte
what is bilirubin
made by liver, break down heme
what are microbes fed on
fed by fermentation of non-glycemic carbohydrates (rafinose, oligosachharied , fibre-soluble, starch )
how colonocytes get energy
from fermentation which produced short chain fatty acids
which micronutrients do not get absorbed
folate, B6, B12 vit K
tell roles of intestinal microflora/microbes
stimulate immune system produce useful nutrients prevent colonisation by harmful bacteria detoxify drugs/ toxins produces CO2, CH3, H2
tell defecation reflex
contraction of rectal muscles
relaxation of anal spinsters
tel thermogenesis
10% of energy goes on absorption and digestion
