a+p3 digestive system

ingestion is the process of

eating and drinking]

mechanical digestion is the process of

physically breaking large food pieces into smaller pieces (ex. chew, mastication) in a way that does not change the food’s chemical makeup

chemical digestion is the process of

chemically breaking down food molecules into smaller molecules via enzymes (going through digestive tract) in a way that changes the food’s chemical makeup

the motion of peristalsis is

wave-like, in the GI tract to move food along

the function of lacteals in the absorption stage is

to absorb digested lipids. specialized lymph capillaries in the villi of the jejunum

the small intestines, in order, go from

duodenum, jejunum, illeum

accessory organs of the digestive system are

glands- exocrine/endocrine

endocrine glands secrete into

blood

exocrine glands secrete into

body surfaces, body cavities

endocrine glands create

hormones

the pancreas is

both an endocrine and exocrine egland

the liver is the

largest gland in the body

the main exocrine secretion of the liver is

bile

the gall bladder functions to

store and concentrate the bile produced by the liver

the three places in the GI tract where chemical digestion occurs are

mouth, stomach, duodenum

the mouth’s role in chemical digestion is

step 1 of carbohydrate digestion only

the stomach’s role in chemical digestion is

step 1 of protein digestion only

the duodenum’s role in chemical digestion is

completion of carbohydrate and protein processes, all lipid digestion

the three macro-nutrients are

carbohydrates, proteins, lipids

all carbohydrates are

saccharides (mono, di, poly)

the 3 most common monosaccharides in human nutrition are

glucose, fructose, galactose

the most important monosaccharide is

glucose

glucose is

the primary energy source

monosaccharides are

the simplest from of saccharides (mono=1)

disaccharides are

2 monosaccharides linked together

the 3 most common disaccharides are

sucrose, maltose, lactose

sucrose is made of the two monosaccharides

glucose and fructose

maltose is made of the two monosaccharides

glucose and glucose

lactose is made of the two monosaccharides

glucose and galactose

polysaccharides are

many monosaccharides (predominately glucose) linked together

the 3 most common polysaccharides are

starch, glycogen, fiber

starch is

how plants store glucose

glycogen is

how animals store glucose

fiber is

undigestible by humans (we do not have a capable enzyme). adds bulk to diet (would have diarrhea without it)

the first step of carbohydrate digestion occurs in the

mouth

the first step of carbohydrate digestion works using an

enzyme in saliva called amylase. breaks polysaccharides into disaccharides

the second step of carbohydrate digestion works using an

enzyme from duodenum to break disaccharides into monosaccharides (the end product)

the only chemical digestion that occurs in the stomach is

protein digestion

the stomach secretes

pepsinogen (inactive)

the stomach breaks pepsinogen into

pepsin with HCl

pepsin breaks large proteins into

peptides and polypeptides

the second step of protein digestion occurs entails

enzymes called peptidases break peptides into amino acids (the end product)

all lipid digestion entails

enzymes called lipases break lipids into fatty acids and monoglycerides (the end product)

enamel is the

hardest substance in the human body (90% mineralized)

the palate separates the

orally and nasal cavities

the uvula prevents

food from entering the nasal cavity

the epiglottis prevents

food from going down into the respiratory system (elastic cartilage of larynx)

saliva is composed of

H2O, mucus, amylase, lysozymes (kill bacteria)

the function of saliva is to

moisten and lubricate food, dissolve molecules for taste, step 1 of carbohydrate digestion

the sections of the pharynx are

nasopharynx, oropharynx, laryngophraynx

the esophagus is the

tube that connects pharynx to stomach

the stomach is the only __ environment in the GI tract

acidic

the rugae are the

folds in the lining of the stomach that will allow it to expand (like pleats in a curtain)

chyme is the

mixture of food and gastric juice (if it comes up it is vomit)

villi are the

functional units of absorption in the small intestines. finger-like projections in mucosa

the haustra are the

pouches of the large intestines

the two blood supplies to the liver are the

hepatic artery, hepatic portal vein

the hepatic artery supplies the liver with

oxygen rich blood

the hepatic portal vein supplies the liver with

nutrient rich blood