digestive/respiratory test Flashcards
the digestive tract is also called
alimentary canal
structure that food passes
oral cavity> oropharynx> laryngopharynx> esophagus> stomach> duodenum> jejunum> ilium> cecum> ascend colon> transverse colon> descend colon> sigmoid colon> rectum
the mechanical process in the oral cavity
mastication
taking in food
ingestion
physical breakdown of food into smaller pieces
mechanical digestion
breaking large food molecules into absorbable nutrient molecules. breaking chemical bonds via hydrolysis)
chemical reactions
releasing substances into alimentary canal to aid in digestion
secretion
releasing wastes into alimentary canal. ex, wastes into bile, defecation.
excretion
moving nutrients, vitamins, water, from alimentary canal into circulation
absorption
vomiting reflexes or stomach acid to protect body from pathogens/toxins
protection
3 pairs of salivary glands
parotid, sublingual, and submandibular
salivary amylase initiates the digestion of what compound and where
carbohydrates in the mouth, and is deactivated in the stomach acid
2 enzymes in the saliva
salivary amylase and lingual lipase
which enzyme begins working in the oral cavity and continues working in the stomach and on what
lingual lipase digest lipids mostly in stomach at a ph 3-6
esophageal glands produce what type of secretions and why
mucous to lubricate and decrease friction
how is food moved down the esophagus
peristalsis in the muscularis externa
what is the function of the lower esophageal sphincter
to prevent acidic chyme form entering esophagus from the stomach
semiliquid substance produced by stomach
chyme
what cells are present in the gastric glands and what stimulates them
g-cells, parietal cells, chief cells, mucous cells are stimulated by ach, histamine, and gastrin
what do g cells produce and the function of product
gastrin: stimulates gastric secretion, relaxation of pyloric and ileoceacal sphincters, simulates intestinal motility
what do parietal cells produce and products function
HCl and intrinsic factor that is needed for the absorption of vitamin b12 in the small intestine
what do chief cells produce and function of their product
pepsinogen the proenzyme that becomes pepsin when it hits stomach acid digest proteins and gastric lipase digests lipids
overall what nutrients get digested in the stomach
proteins and lipids. no absorption
mucous cells do what
produce mucous that covers the interior surface to protect epithelium from acid chyme and digestive enzymes. they come from mucous neck
how is HCl secreted from parietal glands
parietal cells produce carbonid anhydrase from h2o and co2. h2co3 gets broken down to h+ and hco3-. an anion trade occurs by countertransport cl- through gates and hco3- to interstitial fluid. h+ gets active transport to lumen of gland
how does pepsin get activated
pepsinogen is released from the chief cells and are only activated by the acidity to become pepsin
the mixing bowl of gi tract
duodenum, neutralizes acids
most chemical digestion and nutrient absorption occurs here
jejunum
what are villa and their function
finger like projections of the mucosa in small intestine to increase surface area
what are micro villa
tiny projections of plasma membrane of cells to increase surface area
what are lacteal
they are lymphatic capillaries that absorb lipids and fat soluble vitamins (ADEK). they are super permeable
what are brunner glands
mucous glands in the duodenum. the secrete an alkaline mucous to protect duodenum from acidity of chyme
what brush border enzymes
integral membrane proteins in the small intestine. they initially digest materials in contact with the brush border. they digest material in lumen once shed. located on the micro villi
what does cck and secretin do
stimulate secretions from the pancreas and gallbladder. inhibitors gastrin and cause pyloric sphincter contractions
what’s cck do
stimulates gallbladder so bile enter’s duodenum
which class of enzymes get secreted as inactive pro enzymes
proteolytic from pancreas. activated after reaching small intestine
pancreatic juice is made by what cells
acinar cells
what neutralizes chyme
pancreatic juice having carbonates in it
what organ produces bile, what organ stores it
liver, gallbladder
how do bile salts aid indigestion digestion
emulsify lipids into smaller droplets and provide greater surface area for digestive enzymes
sodium transporters absorb what
glucose and amino acids
What is haustral churning
segmentation movement that mixes material in gi tract
mass movements in large intestine
powerful peristalsic contractions move fecal matter from transverse colon to rectum
water reabsorption occurs where
cecum to transverse colon
vitamins produced in large intestine
vitamin k, b5, biotin
what breaks down food in large intestine
bacteria
in large intestine what is NOT produced
enzymes
water absorption
passively through an osmotic gradient
how do fatty acids diffuse
through cell membrane and eventually packaged into chylomicrons
