Digestion 1 Flashcards
what are other names for the gastrointestinal tract
alimentary canal and gut and GI tract
where does the gastrointestinal tract go from
mouth to the anus
what is the function of the accessory organs
secrete into the GI tract
where are the accessory organs
adjacent to the GI organs
what secretes saliva
tongue, parotid gland, sublingual gland
what secretes bile
liver and gallbladder
what makes digestive enzymes
pancreas
what is vestiual (not in use)
appendix
what is the main function of digestion
systematic disassembly
what re the three macronutrients
carbohydrates, lipids, proteins
what are carbohydrates broken down into
sugars
what are lipids broken down into
fatty acids and glycerol
what are proteins broken down into
amino acids
what must happen to macronutrients
they need to be broken down into the smallest building blocks to be absorbed
what are the only things that have co-transports
things that are absorbed(like urinary)
what happens to things that are not broken down
they are defecated out
what is putting food in mouth
ingestion
what is the breaking down of big chunks into smaller particles
mechanical digestion
what requires no chemical change and is the chewing and stomach churning
mechanical digestion
propelling of particles down the GI tract
propulsion
breaking down particles to the smallest building block
chemical digestion
taking nutrients from the lumen into the lymph/tissues
absorption
what is the gut brain
intrinsic nerve plexuses
what reacts without input from the brain(makes own decisions)
intrinsic nerve plexuses
what is digestive activity regulated by
long and short neural reflexes and hormones
what are the three receptors that aid the gut brain
osmoreceptors(salt), mechanoreceptors(stretch), chemoreceptors(chemo)
describe the short reflexes
stays in the gut
makes a local decision and sends out signal to smooth muscle
ex/starts contraction and secreting of juices
describe the long reflexes
goes up to the brain and back
inputs make stomach realize there is food
sends afferent
stimulates secretion and digestion
what has the second most amount of neurotransmitters in the body
gut
what allows autoregulation to happen
short reflexes
what is not involved in digestion because they are too slow
steroids
stretching of any part of the digestion tract _______ upstream processes and _______ downstream processes
slows;stimulates
what is accelerated propulsion
gets things out(defecate) and clears the way for food
large intestinal peristalsis
what stimulates large intestinal peristalsis
gastric decension
what happens once the small intestine is full
the rate of the stomach emptying is slowed down
what relays the information that the small intestine is full
gut brain
what can override digestion(gut brain)
cognitive centers of brain
what anti-infection things are contained in saliva
antibodies, lysozyme, defensins, and amylase
what percent of saliva is water
99%
what is one of the functions of saliva
minimize infection
describe amylase
enzyme of carbohydrate digestion
the longer food is in mouth, more you can break it down(ritz cracker becomes sweet)
what mechanically breaks down food
mouth
what is food propelled through the ailmentary canal by
peristalsis
what is food mixed by as it goes through the ailmentary canal
segmentation
what is a chunck of swallowed food moving though the gut
bolus
how does bolus enter the stomach
gastroesophageal sphincter
what is the function of the stomach
acts to grind
what is the shape of the stomach and why
J shaped and has greater and lesser curvatures
how many layers of the GI tract
4
what looks like the brain
physically grinds food into particles
is a modification of the interior layer of stomach
rugae
what is a stomach growl
rugae moving together
what makes stomach better at digestion(stronger)
oblique layer
what does the stomach have
specialized secreted cells
what are the layers of the GI tract
serosa-muscularis externa-submucosa-mucosa
what is microscopic and creates surface area for partially digested food to contact interior lining of stomach (epithelial cells)
gastric pits
further down(deeper) modified gastric pits
gastric glands
what is the pH of the stomach
acidic
what is in the gastric pit to prevent acid from getting in and touching the cells(or at the very least, neutralize it)
olkaline mucus
what is acidic mucus with an unknown function
mucus neck cells
HCl-down to pH2
parietal cells
make pepsinogen (chemically break apart proteins)
chief cells
hormonal stimulates: gastrin, CCK, histamine
enteroendocrine cells
what is the most important enteroendocrine cell because it turns on digestive processes
gastrin
what is an enteroendocrine cell that is local to stimulate acid production
histamine
where is mechanical digestion mostly completed
stomach
what does the chemical digestion of proteins in the stomach lead to
individual amino acids-simplest building blocks
what stimulates parietal cells to make HCl during chemical digestion
gastrin
what straightens protein(makes it flat during chemical digestion )
decreased pH
what is the purpose of straightening the protein in chemical digestion
allows bonds to be accessed by enzymes
what is pepsinogen brokes into/become
pepsin
what is prpsin
enzyme of protein digestion
what does pepsin do during chemical digestion
breaks bonds between amino acids so they can become individual amino acids
