digestion Flashcards
(40 cards)
ingestion
to put food into your body
mechanical processing
chewing, manipulate with tongue, peristalsis
digestion
break food into building blocks
secretion
enzymes, acids, water, bases, mucous
absorption
moving of the building blocks, water, vitamins/minerals, into blood stream
excretion
getting rid of indigestible items
how does digestive system help immune system?
acid of stomach “melts” foreign bacteria
peristalsis
muscular waves found along entire digestive tract to keep it moving - longitudinal and circular muscles - (reverse peristalsis is puking)
oral cavity
teeth, tongue manipulate food into a bolus - salivary glands (sublingual, submandibular, and parotid) produce saliva which starts the breakdown of fats and carbs (salivary amylase)
2 sets of teeth
20 primary teeth and then 32 secondary teeth
types of teeth
incisors (8)
canines/cuspids (4)
premolars (8)
molar (12)
crown
part of tooth above gumline
root
part of tooth below gumline
enamel
covers the crown, hardest biological substance, resists decay
dentin
bulk of each tooth, similar to bone, no cells
pulp cavity
blood vessels and nerves
root canal
where blood vessels and nerves enter the tooth
periodontal ligament
holds tooth in place
pharynx
common passageway for air, food, liquid. has receptors that initiate the swallowing reflex
swallowing
started voluntarily and continued automatically (food=bolus)
esophagus
10 inches long, lubricated by mucus, sphincters on both ends, peristalsis
stomach
stores invested food - mechanical and chemical breakdown - when food leaves it is chyme - sphincters on each end (cardiac or lower esophageal and pyloric) - makes mucus to protect against acid - food triggers release of gastric juices
chemical breakdown
gastric juices help to break down proteins, fats, and carbs. HCl (stomach acid) kills bacteria (has pH of 2)
acid reflux
acid from stomach moves into esophagus because of weakening of cardiac sphincter - heart burn, indigestion