GI 1 Flashcards
this is 2 layers of peritoneum that has loose CT in between and holds organs in place
mesenteries
this layer of the GI tract is the protective outer layer that is continuous with mesentery and peritoneum and contains nerves, lymph, and blood vessels
serosa
this layer of the GI tract has circular and longitudinal muscles
muscularis
this layer of the GI tract has glands and vessels around the lumen
mucosa and submucosa
this layer faces the lumen of the GI tract
mucosal layer
this layer of the GI tract faces the blood
serosal
PS innervation of upper GI tract
vagus nerve
PS innervation of lower GI tract
pelvic nerve
for PS innervation of the GI tract, postganglionic may be cholinergic or…
peptidergic
this innervation of the GI system controls chyme osmolarity and acidity and concentration of specific digestion products
intrinsic/ enteric
hormones of the GI tract include…
gastrin, CCK and secretin
paracrine molecules of the GI tract include…
histamin and somatostatin
these molecules are used in the GI tract for direct control
neurocrines
glucose
fructose
galactose
are what type of carb?
monosaccharides
sucrose
maltose
lactose
are what type of carb?
disaccharides
statch
glycogen
cellulose
are what type of carb?
polysaccharide
what are three major types of lipids?
triglycerides
cholesterol
phospholipids
this phase of digestion includes smelling, seeing, or thinking about food
cephalic phase
this phase of digestion occurs in the stomach
gastric phase
this phase of digestion occurs in the small and large intestines
intestinal phase
these types of teeth bite or cut off food
incisors and canines
this type of tooth grinds food
molar-type
this reflex controls basic movements involved in chewing and is from the medulla
mastication reflex
chewing food increases ______
surface area
this salivary gland is the largest and is anterior to the ear
parotid
this salivary gland is on the posterior half of the inferior mandible and the duct enters the oral cavity laterally to the lingual frenulum
submandibular
this salivary gland is the smallest and is under the tongue
sublingual
saliva is high in ____ but low in ____ and ____
K+
Na+ and Cl-
true or false: saliva contains HCO3- buffers
true
is saliva production mainly PS or sympathetic?
PS
what main enzymes are produced and released in the oral cavity?
amylase
lipase
what glands release lipase?
sublingual glands
what activates lipase?
stomach acid
this sphincter involved in swallowing is striated and is conscious control
upper esophageal sphincter
this sphincter involved in swallowing has no conscious control
lower esophageal sphincter
in this phase of swallowing, the bolus of food moves from the oral cavity to the pharynx
voluntary oral phase
in this phase of swallowing, the upper esophageal sphincter relaxes for the food bolus and the epiglottis is tipped posteriorly to block the trachea
pharyngeal phase
in this phase of swallowing, stretching of the food bolus causes peristalsis and the opening of the lower esophageal sphincter
esophageal phase
what 2 things do parietal cells release?
HCl and intrinsic factor
what conversion does HCl aid in?
pepsinogen–> pepsin
are carbs broken down in the stomach?
no, amylase is deactivated by HCl
what is the purpose of mucus in the stomach?
protection from HCl
this molecule is released from parietal cells and binds with vitamin B12 which is necessary for RBC production
intrinsic factor
lack of intrinsic factor can lead to what condition…
pernicious anemia
what do ECL cells release?
histamine
what do chief cells release?
pepsinogen
what do G-cells release?
gastrin
what is the order of stimulation of the stomach cells?
G-cells
ECL cells
parietal cells
chief cells
this refers to a rebound increase of HCO3- in the blood with increased stomach acid production
alkaline tide
an alkaline tide can _______ (+/-) plasma and urinary pH
increase
what are 4 agents that inhibit HCl secretion?
PPIs
H2 antagonists
PS antagonists
Prostaglandins
this syndrome is due to a gastrin-secreting tumor that causes high circulating levels of gastrin
zollinger-ellison syndrome
in zollinger-ellison syndrome, an overactivation of H+ release leads to what 2 issues…
duodenal ulcers
reduced pancreatic lipase production
what do D-cells secrete and what triggers it?
somatostatin is triggered by low stomach pH
what is the function of somatostatin?
inhibit stomach hormone activation and H+ secretion
list the amount of time each macromolecule spends in the stomach from least time to most.
carbs
proteins
lipids
this type of cell in the intestine lines the lumen and secretes mucus
goblet cell
what part of the digestive tract is more susceptible to ulcers?
duodenum- H+ from the stomach
what hormones are released as a part of the enterogastric reflex when the duodenum senses stretch, acidity, and fats?
secretin
CCK
this is released from s-cells due to low stomach pH and causes the release of HCO3- from the pancreas
secretin
this is released as part of the enterogastric reflex due to presence of fats and amino acids and stimulates these 3 major functions…
release of enzymes from pancreas
release of bile by liver and gallbladder
reduces rate of stomach emptying
what type of cell releases CCK?
I-cells
this is the primary stimulant for enzymatic secretion in the intestinal phase
CCK
what structure forms the brush border?
microvilli
this is a microenvironment for enzyme release and digestion/ absorption
brush border
