2-mouth and esophagus Flashcards
what is the cephalic stage
receptors in head stimulated by sight/smell/ emotions
how is the cephalic stage activated (neurons)
parasympathetic fibres activate neurons in the GI nerve plexi (Extrinsic)
what is the gastric phase triggered by
stomach receptors triggered by distension, acidity, a.a, peptides
what kind of reflexes mediate the gastric response
short and long reflexes (gastrin and ACh)
what is the intestinal phase triggered by
receptors in the intestine stimulated by distension, acidity, osmolarity, digestive products
what kind of reflexes mediate the intestinal response
short and long reflexes and hormones (secretin, CCK and GIP)
where in the brain control food intake
hypothalamus
where is the feeding center
lateral region
what does activation of the feeding center do
make you HUNGY
what happens with a lesion in the feeding center
lose weight
where is the satiety centre
in the ventromedial region
what happens when you activate the satiety center
feel :FULL
what happens with a lesion in the satiery center
overeat
what does activation of the lateral center do
make you HUNGY
what happens with a lesion in the ventromedial center
overeat
what are the 2 orexigenic factors
neuropeptifde Y (NPY) ghrelin
what does NPY do
neurotransmitter in hypothalamus that stimulates hunger
what does ghrelin do
stimulates release of NPY
where is ghrenlin released and when
endocrine cells in stomach during fasting
4 anorexigenic factors
leptin, insulin, peptide YY, melaocortin
where is leptin released
adipose
what does leptin do
help with long term food intake decrease, decreases NPY release
where is insulin released
pancreas
where is peptide YY released
intestine
where is melanocortin released
hypothalamus
where is the thirst center
hypothalamus
what is the most important regulation of water intake
increased plasma osmolarity
what is released when there is a sensed increased plasma osmolarity
vasopressin
what does vasopressin do
conserves water at kidney
what is stimulated when there is decreased plasma volume
baroreceptors in cardiovascular system
what do the baroreceptors do when there is decreased osmolarity
angiotension 2 released, causing increased thirst
what are the three salivary glands
parotid
submandibular
subglingual
what do the parotid glads secrete
watery(serous) secretion
what the submandibular glands secrete
serous/mucous secretion
what do the sublingual glands secrete
mucous
is saliva hypotoic, isotonic or hypertonic and why
hypotonic to help it dissolve food
is saliva acidic basic or neutral
alkaline to neutralize acidic food
what electrolytes in saliva
which ones more and less
rich in K+ and HCO3-
also Na+ and Cl-
which enzymes are in saliva
amylase and lipase
what are glycoproteins
component of saliva
mucin (with water makes mucous)
what acidity is initial saliva secretion from acinar cells
isotonic (acinar later is leaky)
which compounds are actively secreted from acinar cells into the acinus area
Cl-, K-, HCO3-
which compounds are released from acinar cells paraceullary
Na+, H2O
what is the role of myopithelial cells
contract and expel saliva from acinus into duct
what do ductal cells do to saliva
make it hypotonic and alkaline
are ductal cells permable to water
no
are acinar cells permable to water
yes
which hormones control salivary glands
none!
does parasympathetic or sympathetic do more stimulation for salivary gland function
parasympathetic
is lingual lipase deactivated in the tummy
no, it is acid stable
what is xerostemia
dry mouth due to impaired salivary secretions
what is the larynx and where is it
voice box
between pharynx and trachea
what is the epiglottis and what does it do
tissue flap that covers laryns and trachea when swallowing
what is the pharynx
the throat passage common to food and air
what does the soft palate do in the swallowing reflex
soft palate elevates to prevent food entering the nasal passages
what does the epiglottis do during the swallowing reflex
covers the glottis to prevent food from entering the trachea
where does skeletal muscle cover the esophagus
upper third
where does smooth muscle cover the esophagus
lower two thirds
what does the stratified squamous epithelium do
protect esophagus from abrasive food
where is the upper esophageal sphincter
just below pharynx
what is the main driving force of swallowing
persitalsis
are the salivary glands essential for life
no, but for a high quality life (i think)
