digestive system

how many teeth do adults have?

32

what is food mixed with saliva is called?

bolus

what is separating the esophagus from the stomach?

the esophageal sphincter

what are the 3 parts of the small intestine?

duodenum, jejunum, and ileum

how long is the small intestine?

22 feet (duodenum = 10 inches, jejunum = 8.5 ft, ileum = 11.5 ft)

what is the function of the liver?

to make bile in order to emulsify lipids

what is the function of the pancreas?

to make bicarbonate to neutralize the chyme and to make digestive enzymes (pancreatic amylase, pancreatic proteases, and pancreatic lipase)

what is the function of the gall bladder?

store bile

how long is the large intestine?

6 ft

what is the order of the large intestine?

ascending, transverse, descending, sigmoid, rectum, anus

what is the enzyme in saliva that breaks down bacteria?

lysozyme

what is the enzyme in saliva that digests carbs and starch

amylase

what is the enzyme that digests proteins?

pepsin

what is the substance that emulsifies fats

bile

rhythmic contractions of the digestive tract that move food along the canal

peristalsis

where does mechanical digestion occur

in the mouth and stomach

what is the pH of the stomach

1-3

how does digestion start and why?

digestion begins in the mouth when the teeth chew food and the salivary glands coat it to prepare to be swallowed

what are the teeth made of?

enamel

what prevents food from entering your trachea?

epiglottis

what key factor allows for maximum absorption?

the surface area of the small intestine

what are the folds in the stomach called? what are the functions of them?

rugae

storage, surface area, mechanical mixing, and protection

what is the function of mucous?

to protect, lubricate, and moisturize tissues

what 3 types of cells are in the stomach and what do they do/ produce?

parietal cells, chief cells, and mucous cells

HCl, pepsinogen, and bicarbinate-rich mucous

where are the sphincters in the stomach area?

the lower esophageal sphincter (LES) at the top and the pyloric sphincter at the bottom

where does absorption start?

the small intestine

what are the 2 types of digestion?

mechanical and chemical

what types of tissue lines the intestinal tract?

simple columnar epithelium

how long is the digestive system?

approx. 30 ft

what is bile? what does it do?

a greenish-yellow digestive fluid produced by the liver and stored in the gallbladder

essential for digesting fats and removing waste

what structures increase the surface area in the small intestines?

villi

where do proteins, carbohydrates and fats start to be digested?

carbohydrates = in the mouth via salivary amylase

proteins = in the stomach using pepsin and hydrochloric acid

fats = digestion primarily in the small intestine

where does the digestion finish?

the small intestine

what enzymes are in each organ for digestion (mouth, stomach, duodenum)

the mouth = salivary amylase (starches) and lingual lipase (fats)

the stomach = pepsin (proteins) and gastric lipase (fats)

the duodenum = pancreatic enzymes (amylase, trypsin, lipase) and brush border enzymes (lactase, sucrase)

where are these enzymes produced?

primarily in the pancreas, salivary glands, stomach, and small intestine

what kind of digestion occurs in each organ?

mouth = mechanical and chemical

esophagus = mechanical

stomach = mechanical and chemical

small intestine = chemical

how long does digestion take?

36 hours

why do the cells of the digestive system get replenished so often?

to protect against intense stomach acids, digestive enzymes, and mechanical abrasion from food

what subunits to carbohydrates, proteins and lipids break down into?

carbohydrates = monosaccharides (like glucose)

proteins = amino acids

lipids = fatty acids and glycerol

what is the order of the digestive system—mouth to anus?

mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus