Chapter 16- The digestive system Flashcards
what are the two main divisions of the digestive system?
- alimentary tube (extends mouth to anus)
2. accessory organs (teeth, tongue, salivary glands, liver, gallbladder, pancreas)
what are the two complementary process used in digestion?
- mechanical digestion (physical breakdown)
2. chemical digestion (break down of complex molecules into simplier compounds via enzymes)
what are the 3 types of complex organic molecules found in food, and what are their breakdown compounds?
carbohydrates > starch, disacharides, > glucose, fructose and galactose
proteins > amino acids
fats > fatty acids, glycerol
what is included in the oral cavity and what is the purpose of that organ?
- teeth- chewing, mixing *saliva
- tongue - taste, mixing, swallowing
- salivary glands > (parotid/submandibular/sublingual) > saliva via. ducts
- pharynx> (oropharyns/laryngopharynx) > food passageways for swallowing.
- esophagus > moves food from pharyxn > —-peristalsis—- >lower esophageal sphincter > stomach
what is the purpose of papillae on the tongue?
they contain taste buds.
what digestive enzyme is found in saliva?
amylase, which breaks down starch molecules > glucose molecules or to maltose (disaccharide)
where is the reflex centre that controls the voluntary action of swallowing located?
medulla.
what is happening to the LES during GERD?
when this smooth muscle doesnt close completely, acid juices move from the stomach up the esophagus. longterm exposure is bad.
describe the site of creation, function, and site of action for the enzyme: pepsin
organ created: stomach > cheif cells release, pepsinogen (needs HCI to > pepsin)
function: convert proteins to polypeptides
site of action: stomach
describe the site of creation, function, and site of action for the enzyme: HCI
organ created: stomach >parietal cells
function: changes pepsinogen to pepsin, and maintains pH 1-2 in the stomach to destroy pathogens
site of action: stomach
describe the site of creation, function, and site of action for the enzyme: bile salts
organ created: liver
function: emulsify fats
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: amylase (not salivary)
organ created: pancrease
function: convert starch to maltose
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: trypsin
organ created: pancreas
function: concert polypeptides to peptides
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: lipase
organ created: pancrease
function: convert emlsified fats to fatty acids and glycerol
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: peptidases
organ created: small intestine
function: convert peptides to amino acides
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: sucrase
organ created: small intestine
function: converts cucrose to glucose and fructose
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: maltase
organ created: small intestine
function:concerts maltose to glucose
site of action: small intestine
describe the site of creation, function, and site of action for the enzyme: lactase
organ created: small intestine
function: converts lactose to glucose and galactorse
site of action: small intestine
which enzymes are used in the breakdown of carbohydrates>
amylase, sucrase, maltase, lactase
which enzymes are used in the breakdown of proteins
trypsin, pepsin, peptidase
which enzymes are used in the breakdown of fats
bile
lipase
what are the four layers of the alimentary tube, and describe their puepose
- mucosa, > lining, made to secrete mucus to lubricate eh passage of food, and secrete the digestive enzymes
- submucosa > contains enteric nervous system (brain of gut) to innervate the mucosa to regulate secretions
- external muscle layer > 2 layers of smooth muscle, contract to help break up food/mix digestive juices, moves food using peristalsis
- serosa > above diaphragm outer most layer is firbous, below diaphragm it is the mesentery peritineum, (serous membrane)