Digestive System I Histo Flashcards
(46 cards)
the digestive system consists of ____ and ____
alimentary canal (or GI tract) and associated or accessory digestive organs
organs of the GI tract include:
mouth, most of pharynx, esophagus, stomach, small intestine, large intestine
associated or accessory digestive organs
tongue (PB), teeth (PB), salivary glands (S), pancreas (S), liver (S), and gallbladder (S)
major processes of the digestive system
- ingestion
- secretion
- mixing and propulsion (motility capability)
- digestion (mechanical and chemical)
- absorption
- defecation (of feces)
- barrier
- immunologic protection
the oral cavity opens into the oropharynx through an opening called the ____
fauces
between the lips and teeth and between the cheeks and teeth
vestibule
parts of the oral cavity are:
- vestible
2. oral cavity proper
____ produce dentin, ____ produce enamel
odontoblasts; ameloblasts
saliva is ___ and ____; average secretion of ___ to ____ per day
99.5% water ; 0.5% solutes; 1000-1500 ml per day
saliva has protective and digestive roles:
- moisten oral mucosa
- moisten dry foods
- provide medium for food materials to dissolve so they can chemically stimulate taste buds
- buffer contents of oral cavity (bicarbonate and phosphate ions)
- contains amylase that partially breaks down starch (i.e. polysaccharides)
the pharynx connects nasal and oral cavities to the ___ and ____; is a passageway for ___ and ___
larynx; esophagus; food; air
pharynx has respiratory epithelium (which is ____) and some _____
ciliated pseudostratified columnar epithelium; nonkeratinized stratified squamous epithelium
3 parts of the pharynx
nasopharynx, oropharynx, and laryngopharynx
nasopharynx has _____ bc it is an air passageway only; it is superior to the ____
ciliated pseudostratified columnar epithelium; soft palate
when swallowing, the ___ and ____ move superiorly to close off the nasopharynx
soft palate; uvula
the oropharynx has _____ because it is an air and food passageway; it is posterior to the oral cavity between level of ____ and ____
nonkeratinized stratified squamous epithelium; soft palate; epiglottis
the laryngopharynx has ____ bc it is an air/food passageway; it is continuous with both the ___ and ____; extends from ____ to ____
nonkerat. strat. squamous epithelium
esophagus; larynx
upright epiglottis; larynx
organization from lumen outward of alimentary canal
- mucosa (lining epithelium, lamina propria, muscularis mucosae)
- submucosa
- muscularis externa
- serosa or adventitia
lining epithelium of the mucosa can either be ____ or ____
nonkeratinized stratified squamous epithelium; simple columnar epithelium
lamina propria is ____
loose (areolar) connective tissue
muscularis mucosae is _____
smooth muscle tissue
submucosa is ____ and contains ____
dense irregular connective tissue; meissner’s plexus/submucosal plexus
smooth muscle of the muscularis externa contains inner ___ layer and outer ____ layer
circular; longitudinal
inner circular layer can be thickened to form ___ or ____
sphincters; valves
