DIGESTION Flashcards
what is digestion?
the process in which food is broken down into smaller components to be absorbed in the blood stream
what is absorption?
the process of taking food from the gastrointestinal tract to the interior body
what is the function of the mouth?
chews and mixes it with saliva
what is the function of the salivary gland?
releases saliva which contains salivary amylase (an enzyme that speeds up the process of digestion)
what is the function of the pharynx?
swallows the bolus
what is the function of the esophagus?
moves the bolus to the stomach
what is peristalsis?
coordinated muscular contractions that moves food through the GI tract
what is the function of the liver?
makes bile
what is bile?
a digestive fluid- made in the liver and stored in the gallbladder, released into the small intestine where it helps break down fat for absorption
what is the pancreas?
releases bicarbonate to neutralize any acid content, and other enzymes that help with digestion
what is the function of the small intestines?
- absorbs nutrients into the blood
- where most digestion occurs
what is the function of the large intestines?
- aborbs water and vitamins/minerals
- home to intestinal bacteria
what is feces?
body waste
what is transit time?
the time it takes for food to travel through the GI tract
what are enzymes?
protein molecules that speed up the reaction
what is hydrolysis?
a reaction that uses water to break down large molecules
what is condensation?
a reaction where 2 small molecules combine to create a large molecule
what are the 5 tastes among the taste buds
- sweet
- salty
- sour
- bitter
- savoury (umami)
what is salivary amylase?
an enzyme in the saliva that breaks down starch molecules
give one example of mechanical digestion and chemical digestion.
mechanical: chewing
chemical: enzymes such as salivary amylase
what is the function of the epiglottis
covers the opening to the lungs during swallowing
what is heartburn?
when acidic stomach contents lead back into the esophagus
what is chyme?
what the bolus is called when it is mashed and mixed with stomach acid
what are the 3 sections of the small intestine called?
- duodenum
- jejunum
- ileum
what is the structural function of the small intestines?
it has a long length and many folds that provides a large surface area which maximizes absorption
what is the function of bicarbonate?
neutralizes the acid to make the environment in the small intestines neutral for optimal enzymatic activity
what is the function of cholecystokinin (CCK)?
- a hormone that is released when amino acids and fats enter small intestine
- delays stomach emptying
- regulates secretion of digestion-promoting molecules
what is the function of pancreatic amylase?
enzyme that breaks down starches into sugars
what is the function of pancreatic protease?
enzyme that breaks down protein into amino acids
what is the function of lipase?
enzyme that breaks down fat into fatty acids
what is simple diffusion?
when salts freely move from high to low concentrations
what is facilitated diffusion?
when a carrier molecule is needed for substances to move from high to low concentrations
what is active transport?
what a carrier molecule requires energy to move from high to low concentrations
what is osmosis?
when water molecules freely move from low to high concentrations
what are the 4 segments of the large intestine?
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
what is the intestinal microbiota?
bacteria that breaks down unabsorbed food and uses that food to feed itself
how does fibre promote healthy excretion?
fibre absorbs water so when adequate amounts of fibre and water is consumed, feces can more easily be passed
what is an antigen?
a substance found on disease causing agents that identifies them as foreign invaders
what are antibodies?
proteins that interact with antigens to remove foreign invaders from the body
what is an allergen?
a substance that causes an allergic reaction
what is celiac disease?
a condition that triggers the immunne system to damage/destroy the villi of the small intestines when consuming gluten
what is gastroesophageal reflux disease (GERD)?
a chronic condition where stomach acid leaks into the esophagus
what are peptic ulcers?
when the mucus barrier that protects the stomach, esophagus, and small intestine is penetrated, allowing acid and pepsin to damage the GI lining
what are gallstones?
clumps of solid material that accumulate in the gallbladder or bile duct
what is diarrhea?
- frequent, watery feces
- when material moves through the colon (large intestines) too quickly and water is not absorbed
what is constipation?
- hard, dry feces
- when water content of feces is too low
- caused by lack of fibre and exercise, or a weak large intestine
what are hemorrhoids?
frequent diarrhea and constipation which irritates the blood vessels that surrounds the anus
what are lacteals?
lymph vessels in the villi that pick up fat particles
what are capillaries?
small, thin-walled blood vessels where blood exchanges O2 and nutrients for CO2 and waste
what are veins?
blood vessels that bring deoxygenated blood towards the heart
what are arteries?
blood vessels that bring oxygenated blood away from the heart
what is the function of the liver?
- determines if nutrients are stored or delivered to cells
- important for breaking down amino acids, proteins, and lipids
- detoxifies substances that may be harmful (ex. alcohol)
what is the function of the kidneys?
filters out water, miners, and nitrogen containing products to be excreted into the urine
what is metabolism?
the chemical reactions that
- breakdown molecules to produce energy
- synthesize larger molecules requiring energy
what is anabolism?
when larger molecules are synthesized and new bonds form, requiring energy
what is catabolism?
the breakdown of molecules, releasing energy
what is the function of the mitochondria?
cell organs that break down molecules to release energy
what is adenosine triphosphate (ATP)?
a high energy molecules that the body uses to power through activities
what is the formula for cellular respiration?
glucose + O2 –> water + CO2 + energy
what is glycolysis?
the breakdown of glucose
