digestion Flashcards
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
helicobacter pylori
bacteria that causes ulcers by eating mucus
small intestine
chemical digestion and absorption - duodenum, jejunum, and ileum
duodenum
links with liver/gall bladder and pancreas - lots of chemical digestion takes place here
liver
aids immune system and removes toxins - destroys old or damages blood cells - produces bile salts which emulsifies fat - regulates metabolism
gall bladder
stores product of the liver
pancreas
controls uptake of glucose (insulin and glucagon)
diabetes
type 1: you don’t make enough insulin
type 2: a resistance to insulin has occurred
pancreatic enzymes
breaks down proteins, nucleus acids, and carbs. turns chime into pH of 8
jejunum
last bit of digestion getting macromolecules into their single building blocks for absorption
ileum
absorption - diffusion and active transport
vitamins
ADEK are fat soluble and are stored in the fat, B complex, C water soluble - only absorb what is needed
messenteric blood vessels
all nutrients leave the small intestines via these and enter liver for processing
cecum
reabsorbs bile salts and sends them back to the liver
colon functions
absorbs water, breakdown of toxin so
insulin
allows glucose to be absorbed into the small intestines
glucagon
releases glucose from stored glycogen
