upper digestive tract Flashcards
ingestion
take in food
digestion
break down food (physically and chemically)
absorption
nutrients enter bloodstream
defecation
release of indigestible food
alimentary canal
mouth to anus
gastrointestinal tract
stomach and intestines
accessory digestive organs
salivary glands, teeth, pancreas
mucosa
innermost layer of GI wall
walls of the GI
4 layers
mucosa, submucosa, muscularis, serosa
connective tissue that is thicker than mucosal later
submucosa
muscular layer inner layer(circular) and outer layer(longitudinal) smooth muscle
muscularis
outermost layer of GI wall- the serous membrane
serosa
hard palate
consists of four bones – two maxillae and two palatines
soft palate
forms partition between mouth and nasopharynx
Uvula
suspended from the midpoint of posterior border of soft palate
four types of papillae
circumvallate
fungiform
foliate
filiform
Circumvallate
large, form and v-shaped row at posterior of tongue, to be tasted substance must enter a moat-like depression surrounding the papillae to contact taste buds
fungiform
found on sides and tip of tongue
Foliate
leaflike ridges on the posterior and lateral edges of tongue
Filiform
filamentous and threadlike, whitish coloration, distributed over the anterior two-thirds of the tongue
Do not contain taste buds
Lingual frenulum
fold of mucous membrane in the midline of the undersurface of tongue that anchors tongue to floor of mouth
salivary glands has 3 pairs
parotid glands
submandibular glands
sublingual glands
Parotid glands
anterior to ears, produce a watery type of saliva containing enzymes but no mucus
Submandibular glands
contain both enzyme and mucus producing elements
Located below the mandibular angle
Sublingual glands
lie in front of submandibular glands, empty secretions into floor of mouth
Produce only mucous type of saliva
Saliva
a mix of mucus and serous fluid
Moistens and binds food together into a bolus
deciduous teeth
baby teeth (28)
permanent teeth (32)
teeth classified according to shape
incisors
canines
premolars and molars
incisors
chisels shaped cutting
canines
fang like tearing and piercing
premolar and molars
broad crowns and rounded tips, grinding
root
embedded in jawbone
Outer surface of root covered by Cementum
Cementum
attaches tooth to periodontal membrane, holds tooth in place
Dentin
bonelike material, underlies enamel, bulk of tooth
Pulp cavity
central cavity, contains pulp that supplies nutrients to tooth tissues and provides sensation
Root canal
where pulp cavity extends into the root
Esophagus
runs from pharynx through diaphragm to stomach
Upper esophageal sphincter (UES)
helps prevent
Air from entering esophagus during respiration
Relaxation of the UES permits burping
Lower esophageal sphincter (LES)
also called cardiac sphincter
Located at the junction of the esophagus and stomach
Contains stomach contents with stomach full and churning
Fundus
expanded part of the stomach lateral to cardiac region
body (stomach)
midportion of stomach
Pylorus
terminal part of stomach; continues to small intestine through the pyloric sphincter
Greater curvature
Lesser curvature
convex medial surface
concave medial surface
Lining of stomach =
folds = rugae w/ gastric pits
Gastric pits lead to
Gastric glands producing Gastric juice
Intrinsic Factor
substance needed for the absorption of B12
Chief cells
produce protein digesting enzymes
(pepsinogen->pepsin)
Parietal cells
produce HCl; makes stomach contents acidic and activates other enzymes
Enteroendocrine cells
produce local hormones (Gastrin); important in digestion
after food has been processed
chyme
