GI System - Lecture 2 Flashcards
what are the 3 pairs of salivary glands
parotid, sublingual and submandibular
where are the 3 salivary gland located in the mouth
side of face, in the jaw and under the tongue
what are the components of saliva
water, mucins, alpha-amylase, electrolytes and lysozymes
what NS controls the salivary glands
parasympathetic and sympathetic
what nerves control the salivary gland in the parasympathetic NS
cranial nerves VII (facial) and IX (glossopharygneal)
which nerve controls the GI tract in the parasympathetic NS
vagal nerve
what type of nerve is the vagal nerve
cranial nerve
the stimulation of the parasympathetic NS in the salivary gland causes what
profuse watery salivary secretion
stimulation of the sympathetic NS in the salivary secretion causes what
small volume of viscous salivary secretion
what two receptors are activated to control the activation of saliva in the SNS
alpha1 adrenoceptors (high mucus content) and beta2 adrenoceptors (high amylase content)
what is the function of the soft palate in the mouth
controls for the connection between the nasal area and the oral area
what is a bolus
ball of chewed food
as the bolus approaches the oesophagus, what happens
upper oesophageal sphincter (valve) relaxes and epiglottis covers opening to the larynx
what is peristalsis
sequence of contractions of pharyngeal muscles to push the bolus down the oesophagus
what happens during receptive relaxation of the stomach
relaxation of thin, elastic smooth muscle of gastric fundus and body
what happens when food is digested too quickly
it changes osmolarity (low to high)
what is intrinsic factor
a substance secreted by the stomach which enables the body to absorb vitamin B12
what is the upper stomach called (near the sphincter)
cardiac region
what is the antrum
bottom of the stomach
what is the pyloric region
the region that separates the stomach from the duodenum (small intestine)
what is the extra muscle layer in the muscularis externa of the stomach
oblique muscle layer
where is the mechanical digestion located at in the stomach
antrum
what do gastric glands do
responsible for the control of gastric secretion
what does the body of the stomach secrete
mucus, HCl, pepsinogen and intrinsic factor
what does the antrum secrete
gastrin
what cells secrete gastrin (hormone) in the stomach
G2 cells
what does the surface of the mucous cell secrete
mucine
what does mucous neck cells secrete
mucus
what do chief cells in the gastric gland secrete
pepsinogen
what do parietal cells in the stomach secrete
intrinsic factor and HCl
what is the function of HCl in the stomach
used for sterilization and digesting food
what does CO2 react with in the stomach and what does it produce
it reacts with water and produces carbonic acid (H3CO3)
when the carbonic acid dissociates, what are the products
H+ and HCO3- (bicarbonate)
where does the H+ go after dissociating
to the lumen, in exchange for K
what pump does the H+ go through
potassium proton ATPase pump
where does the HCO3- go after dissociating
to the blood
what pump does HCO3 go through to get to the blood
chloride bicarbonate exchanger
where does chloride go as it enters the parietal cell
goes through another pump to get to the stomach lumen
what is the pH inside the stomach lumen
<2
what is it called when there is a temporary raise in pH of the blood
post brandium alkalinization
what is the enzyme that can phosphorylate any protein
kinase
