Digestion and Metabolism Flashcards
Definition of digestion
the bodies method of breaking down food in preparation for absorption
functions of the mouth
- teeth chew
- tongue positions and tastes food
functions of the pharynx
- passageway for food and air
- swallowing
functions of oesophagus
transports food from pharynx to stomach
functions of stomach
- begins chemical digestion
- delivers bolus to small intestine
functions of large intestine
- absorbs nutrients
- stores waste
functions of small intestine
- digests macronutrients
- absorbs nutrients
- completes chemical digestion of macronutrients
- delivers bolus to large intestine
function of rectum
passageway for faeces
functions of anus
expels undigested material
functions of salivary glands
- saliva moistens food
- amylase digests starch
functions of liver
- produces bile
- associated with processing and storing nutrients
functions of gallbladder
stores and concentrates bile
functions of pancreas
secretes digestive enzymes into small intestine
where are carbohydrates digested
- mouth
- small intestine
- large intestine
which enzymes are involved with carbohydrate digestion
- salivary amylase
- pancreatic amylase
- maltase, sucrase, lactase
where are proteins digested
- stomach
- small intestine
what enzymes are associated with protein digestion
- hydrochloric acid
- gastric pepsin
- trypsin and chymotrypsin
- intestinal peptidase
where are lipids digested
- mouth
- stomach
- small intestine
which enzymes are associated with lipid digestion
- lingual lipase
- bile
- pancreatic lipase
what does salivary amylase do
breaks down shorter polysaccharides and disaccharides in the mouth
what does pancreatic amylase do
breaks down shorter polysaccharides and disaccharides in the small intestine
what do maltase, sucrase and lactase do
break down monosaccharides into the bloodstream in the small intestine
what does gastric pepsin and hydrochloric acid do
breaks down shorter polypeptide chains in the stomach
what does trypsin and chymotrypsin do
break down single amino acids and short peptide chains into the bloodstream from the small intestine
what does intestinal peptidase do
breaks down single amino acids into the blood stream from the small intestine
what does lingual lipase do
breaks down short fatty acid chains in the mouth
what does the enzyme bile do
breaks down small fat droplets in the small intestine
what does pancreatic lipase do
- breaks down short fatty acids into the bloodstream from small intestine
- breaks down long fatty acids into lymphatic system
describe digestion in the mouth
- mastication
- salivary amylase and lingual lipase
- bolus passes through pharynx into oesophagus where peristalsis aids through schinter into stomach
what is peristalsis
muscle contractions of oesophagus
what are 3 segments of small intestine
- duodenum
- jejunum
- ileum
describe digestion in small intestine
- chemical digestion completed
- pancreas, liver and gallbladder release secretions into duodenum
chemical digestion of carbohydrates
mouth = salivary amylase breaks down starch
small intestine = pancreatic amylase break down polysaccarides
large intestine - soluble fibre fermented by bacteria
chemical digestion of lipids
mouth = lingual lipase breaks down shorter fatty acid chains
small intestine = pancreatic lipase breack down small fat droplets into small fatty acid chains and glycerpl
chemical digestion of proteins
stomach = hydrochloric acid uncoils each protein allowing gastric pepsin breaks peptide bonds making shorter polypeptide chains
small intestine = trypsin and chymotrypsin break down shorter peptide chains. intestinal peptidase completes digestion.
what are villi
small spikes on small intestine increasing surface area and allow for greater diffusion of water and nutrients into bloodstream
what are probiotics
bacteria found in certain foods providing numerous health benefits
what is malabsorption
refers to difficulty absorbing nutrients.
malabsorption diseases/conditions
- coeliac disease
- lactose intolerance
- cholestasis
- chron’s disease
signs of malabsorption syndromes
- pale and frothy stools
- diarrhea high in fat content
treatment of malabsorption syndromes
avoiding or replacing substances malabsorbed
coeliac disease
- definition
- symptoms
- dietary management
- response to gluten consumption. villi become damaged reducing area for absorption of nutrients
- bloating, diarrhoea, vomiting, ab cramps
- strict gluten free diet = NO CURE
lactose intolerance
- definition
- symptoms
- dietary management
- inability to digest disaccaride lactose
- bloating, excess gas
- determine amount you can tolerate as eliminating can cause deficiancies
how to calculate energy expenditure
BMR, physical activity, thermic effect
how to calculate energy balance
intake - expenditure
evaluate energy balance
negative = weight loss positive = weight gain 0 = good energy balance
