Digestive system Flashcards
What re the functions of the digestive system?
ingestion mastication deglutition (swallowing) digestion segmentation (mixing of food with digestive system) absorption peristalsis defecation
What is deglutition?
swallowing
How long is the alimentary canal?
30’ 22’ in living human
what is the name for the oral cavity?
buccal
how many pairs of salivary glands?
3
gut
generally refers to developing stomach in embryo
where is the meissner’s nerve plexus?
submucosa
where are palatal rugae?
hard palate, determine direction of food in the oral cavity, serve as friction ridges
What is the uvula there for?
measure the size of the soon to be swallowed bolus
What about salivary glands?
parotid glands - largest and is below and in front of ear
mumps causes swelling of these
submandibular - inferior to mandible and about midway on inside of jaw
sublingual - on floor of mouth and under tongue
produces salivary amylase
heterodont/ diphyodont
more than one type of tooth morphology
teeth sit in alveoli
humans have two sets of teeth - 20 milk teeth (6mos. 2.5 yrs)
32 permanent teeth (replacement 6-17)
wisdom teeth (age 17-25)
dental formula
types, numbers, positions of teeth
deciduous formula - 12/2, C1/1, DM 2/2 = 20 teeth
permanent formula - I2/2, C1/1, P2/2, M3/3= 32 teeth
gut brain
enteric nerve plexuses that regulate digestive activity all along the tract
the oral mucosa secretes ____ which keep the mouth relatively healthy most of the time
defensins
parietal cells
secrete HCl
chief cells
pepsin (zymogen is pepsinogen) and lipases (responsible for 15% of fat digestion)
Besides the obvious, what is the life dependent acton of the stomach?
secreting intrinsic factor, necessary for maturation of RBC’s, pernicious anemia results without it
triggered by aroma, taste, sight, or thought of food; is suppressed if we are depressed or have no appetite
cephalic reflex, conditioned reflex
bilirubin
pigment from the waste of broken-down erythrocytes
