GI anatomy I

Question 1

what is the oral cavity made up of?

Answer 1

mouth, tongue, teeth, palate, palatine tonsils

Question 2

what is the oral vestibule and the oral cavity proper?

Answer 2

oral vestibule = slit-like space between teeth and lips
oral cavity proper = space between upper and lower dental arches ; where tongue lays at rest

Question 3

what muscles keep food between upper/lower teeth?

Answer 3

buccinator and obicularis iris
-labial frenula = free-edged mucosal folds at midline of lips

Question 4

where are the cheeks formed over? why is cheek fat prominent in babies?

Answer 4

over zygomatic bones and processes
-buccal fat more prominent in babies to prevent collapsing cheeks from sucking motion

Question 5

what are cheek dimples?

Answer 5

-genetic ‘flaw’
-2 bundles of zygomaticus major muscle instead of one
-fovea buccalis

Question 6

what are the gums covered with and attached to?

Answer 6

-fibrous tissue covered with mucus membrane
-gingivae proper attached to alveolar processes (mandible, maxillae, dental)
-excellent blood supply/innervation

Question 7

what are teeth?

Answer 7

hard conical structures set within alveoli of upper and lower jaws

Question 8

how many teeth do children have? adults?

Answer 8

children have 20 primary teeth
adults normally have 32 secondary (permanent teeth)

Question 9

what is the arrangement of secondary teeth in adults?

Answer 9

from back to front:
-molars (3)
-premolars (2)
-canine (1)
-lateral incisor (1)
-medial incisor (1)`

Question 10

what are the parts of a tooth?

Answer 10

-crown, neck, root

Question 11

what are teeth composed of?

Answer 11

-dentin covered by enamel over crown
-cement over root

Question 12

what is the function of the pulp cavity and the root canal?

Answer 12

pulp cavity = connective tissue, vessels, nerves (CN V)
root canal transmits nerve and vessels

Question 13

what is the tongue involved in? innervation?

Answer 13

-mastication, taste, deglutition, articulation, oral cleansing
-innervated by CN XII (motor; hypoglossal nerve)

Question 14

where is the root and body of the tongue?

Answer 14

-root is posterior third
-rest is visible and most motile (body)

Question 15

what do the surfaces of the tongue have?

Answer 15

dorsum (top) and lateral surfaces have papillae (taste buds)
-follate
-vallate
-fungiform
-filiform

Question 16

what are some genetic variation in taste buds?

Answer 16

-PTC “super tasters”
-sodium benzoate

Question 17

what are the three salivary glands?

Answer 17

-parotid
-submandibular
-sublingual

Question 18

what are the functions of the salivary glands?

Answer 18

-moisten mucus membrane of mouth
-lubricate food
-digest starches
- “mouthwash”
-prevent tooth decay

Question 19

where does the esophagus extend to and terminate at?

Answer 19

-from pharynx to stomach
-terminates by entering stomach
-passes though esophageal hiatus (at level T10)

Question 20

how expandable is the stomach?

Answer 20

-2-3 L of food
-reservoir and mixer for enzymatic digestion

Question 21

what is the gastric mucosa?

Answer 21

• smooth inner surface that contracts to form rugae (fold)

Question 22

what are the functions of rugae?

Answer 22

-increase surface area for digestion
-provide elasticity for stomach expansion

Question 23

what is the widest part of the small intestine?

Answer 23

duodenum (~25 cm long)
-majority of digestion and nutrient absorption

Question 24

what does the duodenum recieve?

Answer 24

-chyme (stomach)
-bile (bile duct)
-pancratic fluid (via pancreatic duct)

Question 25

what is a cholecystectomy?

Answer 25

removal of the gallbladder
-minimal changes to digestive tract

Question 26

what are the effects of exocrine pancreatic insufficiency?

Answer 26

maldigestion and malabsorption
-fatigue, anemia, vitamin D deficiency, steatorrhea, abdominal distention

Question 27

where does the pancreas lie?

Answer 27

retroperitoneally
posterior to stomach
-superior to L/R renal arteries and veins

Question 28

what are the functions of the pancreas?

Answer 28

-produce pancreatic juices (alkaline to reduce acidity; digestion)
-glucagon production (turns glycogen–>glucose)
-enzyme production
-produce insulin (glucose–> muscle cells)