Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
367 Cards in this Set
- Front
- Back
|
What are the major functions of the GI
|
1. Ingestion
2. Propulsion 3. Digestion 5. Absorption 6. Excretoin and HOST DEFENSE |
|
|
Injestion is usually
|
taking food into digestive tract vai mouth--anal other option
|
|
|
What are 2 types of digestion
|
Mechanical digestion
Chemical digestion |
|
|
What is the major site of absoprtion
|
small intestine
|
|
|
What are GI host derense
|
barrier
MALT Antibodies |
|
|
How is the GI a barrier
|
secretion of some stuff from absorption
|
|
|
What is Malt tissue
|
Muscusol assoicatied lymphoid tissue
|
|
|
What does Malt tissue do
|
WBC's are found here in GI and prevent antigens
|
|
|
What are main antibodies secreted from GI
|
IGA neturalize microorganisms
|
|
|
IS GI one of few organ espose to outside environment (and OPEN-ended system
|
YES
|
|
|
The provesses involved in normal GI are
|
highly integrate and regulated by NTs, hormones and specializede structures
|
|
|
What stimuuli iniate the normal digestive process
|
mechanical and chemical stulition
|
|
|
What mechanical and chemical stimuli initatie the noraml digestive process
|
pH, increases osmolaitry and streching/distnetion
|
|
|
How does a change in Ph activate or ihibit digestion
|
activate or inbhitit glands that secrete digestive juices,simutlat smooth muscle of GI tract walls
|
|
|
What does an increased osmolaity do
|
pulls fluid in, and causes BM
|
|
|
What are 2 main componets that composes the GI tract
|
1. Alimentary Canal
2. Accesory Digestive Organs |
|
|
What includes the the alimentary canal
|
mouth, pharynx, espophagus, stomach, small intestine, and large intestine
|
|
|
What are the lengths of the mouth, pharynx, espohagus, stomach, small intestine and large intestine
|
mouth, pharyxn--6in
Esophagus--1 ft Stomach 6-10in Small intestine 10 ft large intestine 6 ft |
|
|
What is total ft in living person... What are teh acessory diegestive organs
|
18 ft---
Acessory are teeth, tongue salivary glands, gallbladder, liver and pancrease |
|
|
What is benefit of long length
|
facilitaes absorption thorugh large SA
|
|
|
The salivary glands are composed of 2 types of secretory cells
|
mucous and serous cells
|
|
|
What does serous cells produce
|
watery secretion containing enyzmes and ions
|
|
|
What does mucous cells produce
|
mucus
|
|
|
What are the salivary glands, and largest
|
1. Partoid Gland
2. submandibular 3. sublingual gland |
|
|
What composes saliva, and how much a day
|
water main componenet
and electrolytes, and mucin and amalyse, 1-1.5 L/day |
|
|
What are functions of saliva
|
CAMC
cleanses mouth acts as solvent mositens/lubricates chemical digestion |
|
|
What is function of mucin in saliva, what is function of amalyse
|
lubricates the oral cavity adn hydrates foodstuffs--amalyse--digestion of starches
|
|
|
Protection against mircoorganisms is provided by what in saliva
|
IGA antiboides
Lysozymes Defensin |
|
|
What is lysozyme
|
bacteriostatic enzyme that inhbits bacterial growth in the mouth
|
|
|
What are defensins
|
antibiotic like proteins in salvia
|
|
|
Are there bacteria that live in mouth normally not affected by lysozymes
|
YES
|
|
|
What are the major intestional layers
|
1.Lumen
2. Mucosa 3. Submucosa 4. Muscularisi externa 5. Serosa |
|
|
What are 3 sublayers of Mucosa
|
1. Epithelium
2. Lamina propria 3. Mucscularis mucosae |
|
|
What are 3 functions of Mucosa
|
1. Secretion
2. absorption 3. protection |
|
|
FREE
|
FREE
|
|
|
The epithelium is simple columnar cells, secretes
|
mucus secreting globlet cells, enzyme secreting cells and hormoes secreting cells
|
|
|
THe lamina propria is a connective tissue that contains
|
cappillaries that nurish the epithelium, and MALT cells
|
|
|
What does muscularis mucosae do
|
smooth muscle cells that produce local movments of mucosa
|
|
|
What is function of submucosa
|
connective tissue containing blood veseels and nerves
|
|
|
What is function of muscularis externa
|
inner cicular layer and out outer longgituatl layer of smooth muclse repsonsible for motility
|
|
|
The muscularis externa is responsbile for segmentation and peristalissi, is this where drug act
|
YES
|
|
|
What is function of Serosa
|
connective tissue for 4th meal
|
|
|
What is the MAJOR site of digestion and absorption
|
small instestin
|
|
|
What are major components of small intestine
|
Duodenum (10in)
Jejunum (8 ft) Ileum (12 ft) Illocecal valve in cadaver |
|
|
What are main functions of duodenum
|
the hepatic and pancreatic secrettions are empited here via the major dudodenal papillia
|
|
|
What are major functions of jejunum
|
fluid and nutritent absopriton and hormone production
|
|
|
What are major functions of illeum
|
bile acid reabsorption and Vit B12 + fat sobule vitamin absorption
|
|
|
Where does most drug action occur or absorption
|
illeum
|
|
|
What is ileocecal valve
|
msucular sphinter which separates the ileum from teh colon
|
|
|
What are the structural features of the small intestine that enhance digestive processes
|
Cicular folds
and Villi |
|
|
What are functions of cicular folds
|
force chyme to mix through the lumen slowing movement increasing absorption
|
|
|
What are functions of villia
|
increase SA x1000, to increase absorption
|
|
|
What are within each villi
|
cappilary bed, and Lacteal (lymph cappliary)
|
|
|
What is funciton of lacteal
|
component of lympathci systme and fat absorption
|
|
|
Betweent the villi the mucos of SMALL intestine is studded with pits called
|
intestional crypts
|
|
|
What are funciton of intestional cyrpts
|
secretes intestional juice
|
|
|
The submucosal glands in highest conc
|
duodenum
|
|
|
What is function of submucosal glands
|
release Bicarb to neutralize acidic chyme from stomach
|
|
|
What are 4 features of the large intestine not seen anywhere else
|
Teniae coli, the haustra, and epiploic appendages, and appendix
|
|
|
What is function of tenia coli
|
smooth muscle the makes large intestine bunch up to form hastrum
|
|
|
The large intestine is 2.5 inches in diameter what is mall intestine diameter
|
1.5 inches
|
|
|
What does large intestine promote
|
storach of feces
|
|
|
Are there ciuclar folds or villic in large intestine
|
NO
|
|
|
What are special cells of large intestine
|
Columnar cells and Crypts (DEEPER)
|
|
|
What is purpose of NUMEROUS crypts in large intestines
|
lots of goblet cells here, which secrete mucus which lubricate feces
|
|
|
What is purpse of columnar cells
|
water reabsorption
|
|
|
Where are the intestinal bacteria
|
cecum and colon
|
|
|
Is there a farily equal mixture of aerobes and anaerobes
|
YES
|
|
|
What are functions of intestinal bacteria
|
SPD PF
SYnthetis of vitamin B and K Protien/AA degration prevention of colonization with pathogenic organisms Digestion of biles acids, bilirubin and urea fermenation of carbohydrates and fiber |
|
|
Antibiotics can affects interinal bacteraia, which ihbiit Vitamin K synthesis, which affects which patients
|
pateints taking Warfarin
|
|
|
The GI blood suplly is also referred to as
|
splanchic circulation
|
|
|
What % of CO does spanchic ciruclation receive
|
25% of CO
|
|
|
The liver receives what % of splanchic circulation
|
65% through thorugh PORTAL VEIN--nutrient rich
|
|
|
Blood flow is routed through liver, what implications
|
Nutrients and drug see liver first AKA first pass effect
|
|
|
During digestion portal blood flow increases to
|
85% shutning from SKM
|
|
|
What are 2 functions of lympahic system
|
1. facilitate lipid absorption and transfer into bloodstream
2. host defenese |
|
|
What are 2 main nervous system components
|
1. Autonomic
2. Enteric (Intrinsic) |
|
|
What nervous system involves the CNS (Sympathetic and parasympathetic )
|
Autonomics
|
|
|
What iniates Long relfexes
|
stimulation of mechanica or chemical receptors (VAGUS NERVE
|
|
|
The enteric Nervous system AKA
|
little brain or guyt
|
|
|
Short relfexes are meidated by
|
local enteric nerve plexuses and hormone secretion cells
|
|
|
What is main function of esophagus
|
propulsion of contents to stomach
|
|
|
What is the upper 1/3 of esophagus
|
SKM muslce
|
|
|
What is middle 1/3 of esophageus
|
skeletal muscle and smooth
|
|
|
What is lower 1/3 of espohgaus`
|
smooth muslce (involuntary contorl)
|
|
|
There are Upper adn Lower esophageal sphincters, what does LES result in
|
GERD diseases--problems with swallowing
|
|
|
Where are esophageal glands found
|
submucosa
|
|
|
The esophageal glands found in submucosa do what
|
facilitate food transit by secretion of mucus
|
|
|
Swallowing is coordination of muscles in
|
esophageal wall + upper and lower sphincters
|
|
|
The process of propulsion is called
|
parastalsis
|
|
|
What is dysphagia
|
difficulting swallowing
|
|
|
What is dynophagia
|
pain in swallowing
|
|
|
What are functions of stomach
|
food storage and mechanical and chemical digestion, and FACILITATION of vitamin B12 absorption
|
|
|
Processed food is delivered to the duodenum as a paste called
|
chyme
|
|
|
How much can the stomach store up to
|
1 gallon
|
|
|
What is the stomachs receptive relaxation
|
involuntary neural componetne that allows stomach to relax
|
|
|
What are 4 major sections, and functions
|
Cardia
Fundus/Body--Secretory Antrum--mixing/grinding |
|
|
The antrum secretes
|
gastrin
|
|
|
Gastric function is innervated by
|
autonomic NS--para increase motility
|
|
|
What are the layers of the stomach
|
1. Longituational--propels forward
2. Cicular--squeezes stomach 3. Oblique--facilitates mechanial diestions |
|
|
What does pyloric spinchter do
|
prevents undigested food from leaving stomach too fast--controls stomach emptying
|
|
|
What is the gastric histology
|
Simple columanr eithelium of globlet cell
2 layer mucus Surface layer is viccious, adn bottom layer is rich in Bicarb and Gastric pits |
|
|
The smooth linign of stomach has many
|
gastric pits, with gastric glands, that secrete gastric juices
|
|
|
What composes gastric juice
|
HCL, pepsin, lipase, and intrinsic factor
|
|
|
How much gastric juice is produced on a daily basis
|
3 Liters
|
|
|
When is gastric acid most secreted
|
after eating
|
|
|
What are major gastric cell types
|
ME PC
Mucous neck cells Enteroendorcrine cells parietal cells chief cells |
|
|
What is function of mucous neck cells
|
secretion and precursor to others==cells migrate down and morph into other
|
|
|
What is function of enteroendocrine cells
|
release hormones--gastrin, histamine, and somatostatin, and endorphins
|
|
|
What is fuction of Histamine
|
increases gastric acid secretion
|
|
|
What is function of Gastrin (G cells)
|
Increases Gastric secretion and motility
|
|
|
What is function of somatostatin (D cells)
|
DECRESASES gastric secretions and motility
|
|
|
What is released from Parietal cells
|
HCl + intrinic factor
|
|
|
What does HCL do and from
|
patrieal cell, and digestion and sterilization
|
|
|
What does IF do and from
|
partieal cell, and vitamin B 12 absopriton
|
|
|
What is release from Cheif Cells
|
Pepsinogen
|
|
|
What does Pepsinogen do and from
|
protein digestion from cheif cells
|
|
|
What does mucous neck cell secrete
|
mucous and bicarb for gastroprotection
|
|
|
What secretes Ach and do
|
Parasympathtetic and icnrease Gastric acid secretion
|
|
|
What are 3 phases of gastric secretion
|
1. Cephalic phase
2. Gastric phase 3. Intestinal phase |
|
|
What is the Cephalic phase aka and what happens
|
reflex phase of gastric secretion BEFORE food enters the stomach
|
|
|
What triggers the cephalic phase
|
sight, smell, or though of food
|
|
|
Sight, smell, or though of food iniates
|
parasymatheci + enteric nervous system, which increases gastric acid secretion
|
|
|
How long does cepahlic phase last
|
only a few mintues
|
|
|
When does gastric phase begin
|
once food enters STOMACH
|
|
|
What stimulates gastric phase
|
distenetion, low acidity and peptides
|
|
|
Deistenion, low acidity and presence of peptide causes
|
fruther AcH release, and gastrin is secreted by G cells
|
|
|
How long does gastric phase last
|
3-4 hours
|
|
|
What is main phase were stuff is secreted for digestion
|
Gastric phase
|
|
|
When does intestinal phase begin
|
once food enters duodenum
|
|
|
Once food enters the duodenum is enteric gastrin released
|
YES
|
|
|
What is triggered in intestinal phase
|
Enterogastric reflex is triggered
|
|
|
What does enterogastric reflex do
|
suppresses vagal and local reflexes, and ACTIVATES SYMPATHETIC input
|
|
|
Ultimately what does enterogastric reflex do
|
turns off gastric acid secretion
|
|
|
Is gastric acid necessary for food digestion
|
NO
|
|
|
What activates Pepsionogen
|
Gastric acid secretion and Pepsin
|
|
|
What happen potent acid suppressant beens associated with
|
increased rates of pulmonary and gastric infections
|
|
|
What are 3 main inputs of gastric facid secretion
|
1. Gastrin
2. Ach 3. Histamine |
|
|
What is gastrin receptor
|
CCK-B receptor
|
|
|
What is Ach receptor
|
Muscarinic receptor
|
|
|
Whta is histamine receptor
|
Histamine 2 receptor
|
|
|
What is benfit of different intraceullar signaling pathways (Gastrin and Ach and Histmaine all increase gastric acid secretion)
|
if one pathway is compromised call redundancy
|
|
|
H+ actively pumpumed against a concentration gradient by
|
ATPase pump, activated by Gastrin Ach, and histamine
|
|
|
As H+ are pumped out what accumulates
|
Bicarb accumated
|
|
|
What happen to HCO3
|
is actively pumped into the bloodsteam by Alkaline Tide
|
|
|
Alkaline Tide is only active druing gastric secretion, as it pumps Bicarb into the bloodsteam what happens
|
blood drain cell is alkaline
|
|
|
Whre are inactive H+ transport pumps
|
cytosol
|
|
|
What do prostaglindins release
|
mucous and Bicarb
|
|
|
What are the protective mechanism of the stomach
|
MR TB
protaglandins Blood flow tight junctions rapid cell turnover |
|
|
What do NSAIDS/ASA
|
break down the mucosal layer, and redcues gastroprocetive mechanisms
|
|
|
What are processes involved in neurohoormonal regulation
|
Neuronal and Soluble factors (chemicals)--that result in alterations in motility and secretion
|
|
|
What are the 4 major modes of communication
|
1. Endocrine
2. Paracrine 3. Neurocrine 4. Immune |
|
|
What are characteristic of endocrine
|
involves hormones packaged in secretory granules, and to affect mutiples sites within or outside GI tract
|
|
|
What is release of endorcrine triggered by
|
Changes in pH or osmolarity
nerve input or specific type of molecules |
|
|
What is an example of endocrine
|
signaling when you are full
|
|
|
Wht are acharacterstics of paracrine
|
affect only immediate area,readily metabolized or taken up, and local regulation
|
|
|
What are examples of paracrine
|
Histamine
Protaglainshs Serotonin |
|
|
What are characteristics of neurocrine
|
involes NTs release from nerve endings and efector cells muut have NT receptor
|
|
|
Is neurocrine able to affect local or distant functions but NOT
|
as broadly as endocrine
|
|
|
What are examples of neurocrine
|
Ach, NO, serotonin, VIP, and Substance P
|
|
|
What are charactericstic of immune
|
Release is typically in resonse to an antigens, and affects functions locally
|
|
|
Substanes released from cells assoicated with mucosal immune system is
|
IMMUNE communication
|
|
|
What are examples of immune
|
Histamine and Cytokines
|
|
|
Histamine for ECL is assoicated with
|
Paracrine---histmaine from mast cells is assoicated with mast cells
|
|
|
How is symathetics linked to intrinsic
|
sympathetic neruons may synpase with enteric neurosn or directly innervate secretory or smoth msucles
|
|
|
What does symathetic NT norepinehpine have on instric system
|
SHUTS down
|
|
|
Where do parasympathetic neurons synpase
|
myenteric plexus with Ach---which sppeds up
|
|
|
What sensory nerve transmit pain impulses
|
visceral afferent
|
|
|
Where are 95% of bodies stores this in GI tranct
|
5-HT in Enterochromaffin cells
|
|
|
What type of communciation does 5-HT
|
neurocrine and paracrine action that cause motility and secretion
|
|
|
There are 7 substyes of 5-HT, what ones are most involved in GI
|
1-4
|
|
|
Stimulation of 5-HT leads to
|
increased motility, secretion and possibly pain modulation
|
|
|
What type of communication of Somatostatin
|
Neurocrine adn paracrine
|
|
|
Somatostatin increase sympathetic input, what is it decrease
|
--ihhibit gastric secretion and motility, supresses pancreatic secretions, adn redcues splanhic blood flow
|
|
|
What are the 2 major Intrinsic Nerve plexuses
|
1. Myenteric plexus
2. Submucous plexus |
|
|
Where is the myenteric plexus
|
lies between circulat and longitudal msucle of muscularisis externa
|
|
|
What is main control of myenteric plexus
|
MOTILITY
|
|
|
What are NTs of myenteric plexus
|
Ach, NO
|
|
|
What are are Nerons subtypes of Ach, NO
|
Ach--Stimulatory motor,
NO inhibitory motor, |
|
|
What is main functino of submucosal plexus
|
control motility and SECRETION
|
|
|
How does submucosal plexus contorl motilitya nd secretion
|
by glands and smooth muclse, and blood vessels--vasodilation
|
|
|
What are NT of submucosal plexus
|
VIP, ACH, and Substance P
|
|
|
What does VIP NT do
|
inhbits secreotomotor
|
|
|
What does Ach do
|
stimulate secretomotor
|
|
|
What does NT substance P do
|
sensory
|
|
|
What are the 5 GI hormones
|
1. Gastrin
2. CCK 3. GIP 4. Secretin 5. Motilin |
|
|
What is only GI hormone released in Stomach
|
Gastrin
|
|
|
What is Gastrin strually related peptide to
|
CCK--both syntehzies as propeptides, and cleaved to active forms
|
|
|
Gastrin is released from
|
G cells
|
|
|
CCKS is released from
|
I Cells
|
|
|
Gastrin only has endocrine function, what does CCK have
|
both endocrine and neuroncrine
|
|
|
Gastrin and CKKS bind to what receptors
|
CCK-A and CCK-B-- G protein protein response
|
|
|
Gastrin and CCK singals are regulated via
|
cytoplasmic calcium
|
|
|
What is stimuli for Gastrin rlease
|
Proteins/AA
Neural stimulation Strech Caffeine |
|
|
What is stimuli for release or production of CCK
|
Proteins/AA
Fatty acids Neural stimulation |
|
|
What are effects of Gastrin
|
Increase HCL
Increase contraction of small intestinal muscle Relaxes ileocecal valve |
|
|
What are effects of CCK
|
Pancreatic secretion
Gallbaldder contraction Relaxes spinhicter of oddi Increase actions of secretin, and signals sateity to CNS |
|
|
What hormone is released during intestinal phase
|
CCK
|
|
|
What hormone is released during gastric phase
|
gastric phase
|
|
|
What type of communication is secretin
|
endocrine
|
|
|
What syntheseizes secretin
|
S cells
|
|
|
What is secretin released in response to
|
decreased intraluminal pH, and partailly digested proteins and fats
|
|
|
When is secretin released
|
during intestinal phase
|
|
|
What does secretin do
|
inhibits gastic secretion and molitility
increases pancreatic bicarb and heptaic bile output in small intestine increase effect of CCK |
|
|
What hormones increase effects of secretin
|
CCK
|
|
|
GIP is AKA glucose-dependent insulinotropic pepetid, which is what type of communication
|
endorcine
|
|
|
Where is GIP released
|
K cells
|
|
|
What are functions of GIP
|
Inhibit gastic secretion and SLOWS gastric motility, and simutlates insulin release
|
|
|
What is GIP released in response to
|
Carbs/fats/protein in the duodenum during intestinal phase
|
|
|
Motilin is a 22 amino acid peptide involved in
|
GI moltility
|
|
|
When in motilin released
|
cyclically during fasting state
|
|
|
What does Motilin initiate
|
MMC--migrating motor complex
|
|
|
Erythyromycin is a motilin agents what does this cause
|
diarrhea
|
|
|
Medical term of chewing
|
mastificaiton
|
|
|
MEdial term of swallowing
|
deglutication
|
|
|
Food is manipulated to form a solid mass AKA
|
Bolus
|
|
|
What are 2 main phases of ingestion and swallowing
|
Buccal Phase
Pharyngeal-esophagela phase |
|
|
What happens in Buccal phase
|
Occurs in mouth food is mechanically AND chemically broken down then tongue forms a bolus by pressing agsint palate and food is forced into the oropharynx
|
|
|
Is the Buccal Phase voluntary
|
YES
|
|
|
What happens after food enters in oropharydxn
|
posterior tongue forces food into pharynx
|
|
|
Pharyngeal -Esopheagl phase is INVOLUTNARY it is contorlled byt
|
swallowing center in CNS
|
|
|
What protects the airways
|
soft palate and epiglottis
|
|
|
What 2 ways moves food down esophagus
|
Negative presure and peristalsis
|
|
|
What causes the peristaliss in pharyngeal-esophagel phase
|
streching of mucles
|
|
|
Where does orad contraction take place
|
behind food
|
|
|
Where does caudad distention take place
|
relaction
|
|
|
What causes relaxation in front of bolus
|
NO
|
|
|
What causes contraction behind bolus
|
Ach
|
|
|
What effects LES tone
|
1. Pressure
2. Pregnacy 3. NTG 4. Anti-chlinergic drugs 5. ETOH |
|
|
When does Motility occur
|
both fasting and fed states
|
|
|
Why does motility occur during both fasting and fed states
|
allows movement of indigestible material and secretions during fasting (saliva still there)
|
|
|
What is involved in the stomach ability to relax as volume increases
|
receptive relaxastion through Dosal vagal complex
|
|
|
What is purpose of proximal stomach, so has
|
more resverior--has tonic contractions
|
|
|
What is purpose of Distal protion of stomacfh
|
more as mixer and grinder, results in phasic congtractions
|
|
|
What is the pyloric sphincter AKA
|
gate-keeper
|
|
|
What happens when contents come in contact with CLOSED pylorus
|
results in retropulsion--further mxing up of food
|
|
|
What is sieving
|
pushing smaller moleculres toward pylorus
|
|
|
What does sieving lead to
|
retention of moecules > 1-2 diameters-and prevents food from being digested
|
|
|
The pylorus imtermittently allows chyme to pass--in relaxation--what is needed
|
NO and neural input
|
|
|
What causes the constriction of the pylorus
|
Acid, increased osmolarity or nutrients in duodenum
|
|
|
What hormones causes pylorun constriction
|
CKK, Ach, 5-HT
|
|
|
What causes the contstant peristalic waves of the stomach
|
Pacemaker cells
|
|
|
Where of the pacemaker cells located
|
longiduinal muscle layer
|
|
|
What do the Pacemaker cells do
|
sopontaneous depolarie 3X per minutes establishing the BER
|
|
|
What is the BER
|
bsal electric rhythm
|
|
|
The BER set the maximum rate of
|
CONTRACTION---NOT FORCE
|
|
|
What assures that that each "beat" is transferred to the entire stomach
|
gap junction of stomach
|
|
|
What does BER require to initatie
|
enteric stimuli
|
|
|
What coordinates the tonic and phasic contraction of gastic emptyinh
|
5-HT, and CCK
|
|
|
How does 5-HT coordination of tonic and phasic contractions
|
gastric empting
|
|
|
What does CCK do in coordination of tonic and phasic contractions
|
DECREASES gastric emptinh
|
|
|
What empties faster than solids
|
liquids
|
|
|
What empites the slowest
|
FATS
|
|
|
When fats enters the duodenum what happens
|
CCK is rleased---inhibits Gastric moltility and secretion, slows stomach down
|
|
|
Which food stay in the stomach the least
|
glucose--carbs
|
|
|
Which foods stay in stomach the longeest
|
fat--solid meals
|
|
|
What triggesrs motility during fasting
|
Motilin--MMC
|
|
|
The MMC occuring every 100 minutes and occurs in 3 phases what happens in phase 1
|
Mininal to no acitivty
|
|
|
What happens in phase 2 and 3 of MMMC
|
2--Parasymthatic irregular
3--Intense sweeping contractions regulated by motilin |
|
|
Motilin indirectly leads to release of
|
NO, 5-HT, and AcH
|
|
|
What suppresses motilin release
|
eating
|
|
|
The Small intesting also contain pacemaker cells, which cycle how often
|
12 cycles per minutes
|
|
|
The moltility patterns are desinged to mix food with intestinal secretion and then propel foward--what acommplishes this
|
segemntation---MOVES food BACKWARDS, then peristalisi moves forward
|
|
|
What happesn at the end of each MMC cycle
|
the pylorus is opened to allows passage of contents NO
|
|
|
If MMC presenet in Large intestine
|
NO
|
|
|
Colon is involved in mixing of contents, what type of proppulsino
|
semental propulsion move to each haustrum
|
|
|
What are short duration contractions of Large intestine
|
ciruclar muscle (8sec)
|
|
|
What are long duration contractions
|
taenaie coli (20-60secs)
|
|
|
What are high amplitude progating contactings
|
10 x per day, analgous to MMC
|
|
|
What is gastrocolic reflex
|
eating food triggers stimulation of defecation
|
|
|
What tells you that you need to defecate
|
stech receptors
|
|
|
What is the voluntary anal spincter
|
external anal sphincter
|
|
|
What is the involuntary anal sphincter
|
internal anal spincter
|
|
|
What hormones are involved in internal anal spincter (involuntary
|
VIP and NO
|
|
|
The liver, biliary system and gallbladder are considered
|
accessory digestive organs
|
|
|
What are liver functions generally
|
Syntheissi, secretion, metabolism excretion
|
|
|
What does liver synthetsis and secretion
|
protein, lipids, bile and bilrubin
|
|
|
What are livers metabolis and exretion
|
metabolizes drugs, and exretion lipophic substances
|
|
|
What is function of gallbladder
|
STORAGE and release of bile
|
|
|
What is biliary tract
|
delivery of heatopancreatic secretions
|
|
|
Each functional unit of the liber is called
|
a lobule
|
|
|
Blood flow into liver is
|
potal vein
|
|
|
Blood flow out of liver is
|
interlobular veins to hepatic vein
|
|
|
What does each liver lobules (cell) contain a plate of hepatocytes that have
|
Portal Triad--Protal aterioles, Portal venule, and bile duct
|
|
|
Also in the liver lobules are bile canaliculi, and leaky cappilars AKA
|
sinusoids
|
|
|
Does blood and bile flow in oppoiste direction
|
YES
|
|
|
The liver lobules are made of plates of hepatocytes make up 80% of liver mass, and they are
|
high regenerative
|
|
|
What is a marker of heaptic function
|
protein synthetiss--albumin
|
|
|
Liver detoxes
|
ammonia, drug and bililrubin
|
|
|
What are other liver cells besides hepatocytes
|
Kupffer cells
Sinusidal endothelial cells Stellate Cells |
|
|
What are Kupffer cells
|
macrophaes, and functions as phagocytosis
|
|
|
Sinusoidal endotherlial cells are designed to be
|
permeable--and lack basement memebrane
|
|
|
Stellate Cells
|
Storage of Lipids and fat soluble vitamin A--and have ability to contract
|
|
|
Intrahepatic the bile flows through
|
canaliculi, and chlolangiocyes
|
|
|
AFTER leaving liver Bile flows in right and left hepatic BILE ducts, its release is controled by
|
Major duodenal papilla AKA sphinchter of Oddi
|
|
|
What does Bile do
|
elminates hydrophobic molecules and emulsifies fatas
|
|
|
Wha tis the main component of bile
|
bile salts---ALLOW US TO ABSORB fats
|
|
|
Bile acids are synthsized from
|
cholesterol
|
|
|
What also cholesterol to become a primary bile acid
|
C27 dehydroxalase
|
|
|
What also cholsterole to become a secondary bile acid
|
intestinal bactera
|
|
|
Followign hepatocyte synthesis the primary bile acids are
|
conjuagted with tuarine or glycine prior to secretion
|
|
|
Why are primay bile acids conjugated with taurine or glycine
|
lowers PKA, allows ionizaation and makes more water soluble
|
|
|
The final product of bile are what type of moleucles
|
amphipathic molecules--and can form micelles
|
|
|
Bile undergoes modification in bile ductules, and when does it remian unchanged
|
once it enters teh extrahepatic biliary system
|
|
|
The Gallbladder AKA
|
Cholecyst
|
|
|
The Cholecyst is 4 in, and what is its capacity
|
50ml
|
|
|
What is function of Gallbladder
|
storage and concentration of bile between meals
|
|
|
What are characteristics of Gallbladder
|
1. Columnar epithelium
2. Tight junctions 3. Goblet cells 4. Smooth muscle--allows to contract |
|
|
What causes contraction of Gallbladder
|
CCK
|
|
|
What happens when spinchter of oddi is closed
|
Bile backs up and is stored in Gall baldder
|
|
|
If you have too much cholesterol or not enough bile what happens
|
form gall stones
|
|
|
The majority of bile acids are secreted ARE reclaimed in, AKA
|
ileum--Enterohepatic recycling
|
|
|
The biles salts are ACTIVELY retrnasport into blood how
|
Bile salts reenter the portal circulation from illeum and them are resecreted in new bile
|
|
|
Can drugs be recycled if bond to bile acids
|
YES
|
|
|
What happens to bile acis that make it large intestine
|
DECONJUAGTED by intestinal bacteral, and are PASSIVELY reabsorbed
|
|
|
What are Bile acids bound to as they are actively taken up from the ileum
|
bound to albumin in the portal ciculation
|
|
|
Do very small amounts of bile acids make it to urine
|
TRUE
|
|
|
How do Hepatocytes take up bile acid once in liver
|
by various transporters
|
|
|
Bile acids have negative feedback on
|
cholesterol 7a hydroxylase
|
|
|
Where does bilrubin come from
|
dervied from heme from RBC breakdown
|
|
|
How is bilirubin transported to liver
|
bound to albumin
|
|
|
THe hepatocytes absorb bilirubin what happens after conjugation
|
Hepatocyte can conjugaiton with glucuronic acid, and make direct bilrubin, which is secreted into Bile via MRP2
|
|
|
What happens after Direct Bilirubin is secreted into bile
|
deconjuated by intestinal bacteral to urobiliogen and sterobilogens
|
|
|
10% of Bilirubin is unconjugated, what happens to INDIRECT bilirubin
|
returnd to ciculation--damage liver
|
|
|
Ammonia is the result of protein breakdown mainly in intestines, what is it converted to
|
urea--mainly excreted renally
|
|
|
Ionized NH4+ is excreted
|
fecally
|
|
|
What are the 2 MAJOR functions of pancreas generally
|
exocrine
and endocrine |
|
|
What is the exocrine function
|
difestive---functional unit Acini--pancreatic juice
|
|
|
What is the endocrine function
|
Islets of Langerhans
|
|
|
What are 3 maintpye of enzymes for pancreatic exocrine function
|
Protelytic enzymes (80%)
Amylotic Enyzmes Liplytic enzymes |
|
|
What ar ethe proteolytic enzymes
|
Trypsinogen, chymotrypsinogen, procarboxypeptiade A &B, and proelastase, and Nucleases, ribonucelase and deoxyribnuclease
|
|
|
How are the protelytic enzymes stored and secrte as
|
proenzymes or zymogens
|
|
|
What is importance of proteolytic enzyme being stored inactive
|
dont want to digest pancretatic cells
|
|
|
What are the amylolytic enzymes
|
amylase
|
|
|
What are the lipoltic enzymes
|
lipase, colipase, prophospholipase A2, and cholesterol esterase
|
|
|
What else do panceases secrete besides enzymes
|
water and electrolytes
|
|
|
90% of pancreatic function needs to be lost before exocrine dysfunction becomes
|
clinically evidnet
|
|
|
What is the endocrine functino of pancerease
|
insulin, glucagon, and somatostatin from islet cells
|
|
|
What is main reugator of exocrine secretions
|
Ach--
|
|
|
When are pancretatic exocrine secretions greatest
|
INTESTINAL phase
|
|
|
What are 2 main hormone secretions when acidic chyme and fats enter duodenum
|
Secretin (ACIDIC) and CKK and Ach (bigger)
|
|
|
What has a direct contorl of bicarb
|
secretin which neutralized acidicity of
|
|
|
Secretin stimulates the inercalated duct cells to release Bicarb due to
|
decrease interluminal pH, and paritally digested protein and fats
|
|
|
How are the pancreatic proteases enzymes activated in the small intestine
|
Tyrpin is activated by membrane bound enterkinase--and then typsine active chymotrisinogen, and procarboyxypediate
|
|
|
Amalase and lipase are secreted in active forms but require
|
BILE acids or ions for mamximal acitivty
|
|
|
Where are most nutrients extracted
|
jejunum and ileum
|
|
|
What are dietary carbs broken down into
|
Starches, Disaccharides, Monosaccharids, and fiver
|
|
|
What are complex carbs
|
starches--amylose, and amylopectin
|
|
|
What are carbs easiest absorbed
|
glucose, fructose, and galatose
|
|
|
What are the disaccharides
|
surcose, lactose----sucose is converted into monosaccarides
|
|
|
Monosaccharides need no further digestion, how are starches, disaccharies, and fiber further broken down
|
1. Salivary Amylase
2. Pancreatic Amylase 3. Bursh border enzyme (small intestine) |
|
|
The brush border enzymes are the final step in digestion what are enzymes
|
Sucrase
Lactase Maltase Dextrinase, glucozmylase and ismlatase |
|
|
After sugars are broken all the way down, how is glucose absorbed
|
co tranport with Na+ at level of microvilli
|
|
|
Where does Protein diestion begin
|
Stomach with Pepsin and HCL
|
|
|
What happen after proteins are partially broken down in stomach
|
broken down my pancreatic proteases, and brush border enzymes
|
|
|
What are the brush border enzymes that break down proteins
|
Aminopeptidase
Carboxypetidase Dipetidase |
|
|
Proteins are ultimately broken down into AA and peptides, unlike carbs, more complex proteins
|
di, tri and tetra peptides can be absorbed
|
|
|
How are peptides transported
|
PEPT-1 with H+ for di and tri peptides
|
|
|
Are many drugs transported via peptide transporter, one should avoid levodopa with
|
a high protein meal
|
|
|
How are AA transported
|
via Na+ or H+ cotransport
|
|
|
What is location of lipid digestion, 3 steps
|
1. Gastric lipases, then Small intesitne--bile salts emulsify, and pancreatic lipases form michelles
|
|
|
What require absoprtion via micelles
|
Cholesterol, plant steol, and vitamins ADEK ---Cholesterol requires extra NPC1L1 transporter as well
|
|
|
What allows cholesterol plant seteola dn vitamine ADEK to be emulsified
|
bile salts
|
|
|
What fats can be absorbed without micelles
|
fatty acids and monoglycerdies
|
|
|
What happens to fatty acids and monoglycerides
|
enter enterocytes bcecome triglycerides
|
|
|
What happens to triglycerides
|
b/c chylomicone and is transported to blood steam via lactela
|
|
|
What happens to medium chain fatty acids
|
enter portal circulation
|
