Lecture 31 - Intro to GI Flashcards
name the layers of a cross-sectional gut segment from outermost to innermost
- serosa (adventitia)
- smooth mm. (longitudinal then circular)
- muscularis mucosa
lamina propria
contains loose connective tissue with blood vessels and immune cells
submucosa
under mucosa containing blood vessels, nerves, lymphatics, and glands
what are the divisions of the autonomic nervous system
- sympathetic
- parasympathetic
describe the sympathetic division regarding GI function
inhibitory - decreases motility and secretion
describe the parasympathetic division regarding GI function
stimulatory - increases motility and secretion
what is the job of the myenteric plexus
controls GI motility by regulating contractility in the longitudinal and circular muscles
what is the job of the submucosal plexus
control secretory functions, absorption and blood flow to the GI tract
T/F: most mammals have the parotid, mandibular, and lingual sg
TRUE
polystomatic refers to
a salivary gland with multiple ducts or openings
salvia is secreted by
acinar cells
how is salvia composition modified
resorption of electrolytes
T/F: acinar cells are serous in nature
FALSE - serous, mucous, or mixed
T/F: salivary ducts are intercalated
TRUE
describe parasympathetic innervation of the salivary glands
autonomic/cholinergic
facial n., glossopharyngeal n, and vagus n.
afferent stimuli
describe sympathetic innervation of the salivary glands
B-adrenergic receptors
attack response, not digestion
what causes differences in saliva composition
species diets
what are the 4 main components
- water
- mucus
- enzymes
- electrolytes
what are the 5 functions of saliva
- mastication and deglutition
- antibacterial properties
- initiate nutrient digestion
- evaporative cooling
- provide fluid and buffer for fermentation
alpha-amylase
key enzyme for carbohydrate digestion made by mammals
if an animal eats a diet high in b-linkages, what is needed
bacterial fermentation
what is the role of saliva in heat dissipation
evaporative cooling
what is the main buffer for rumen fermentation
saliva
ptyalism
hypersecretion of saliva
pseudoptyalism
loss of saliva from the mouth due to inadequate swallowing
