Gastrointestinal Physiology Flashcards
1
Q
functions of the G.I tract
A
Motility
Digestion
Absorption
Secretion
2
Q
Motility
A
refers to the movement of the GI tract and serves two purposes
1. moves contents from mouth to anus
2. mixes contents to facilitate digestion and absorption
3
Q
Digestion
A
process of breaking down large particles of food and high-molecular weight substances into smaller molecules
4
Q
Absorption
A
movement of the digestion of the product across the intestinal epithelium into the body
5
Q
Secretion
A
Release of substances into the lumen of the GI which facilitates digestion, absorption and motility
6
Q
What are the components of the digestive system
A
mouth, stomach, small intestine and large intestine
and the accessory organs : Salivary glands, Liver, Pancreas, Gallbladder
7
Q
function of the epithelium of the intestinal wall
A
Barrier of cells that nutrients must traverse to be absorbed into the body
8
Q
Function of the capillaries and lymphatics
A
aid in transport to and form the intestine, deliver O2 and other needed molecules
9
Q
function the circular and longitudinal muscles
A
these layers of smooth muscle allow motile contractions of the intestine
10
Q
function of the myenteric plexus
A
has a rich nerve supply that controls multiple aspects of motility and secretion, known as the brain of the gut
11
Q
function of endocrine cells
A
secrete hormones into blood that regulate digestion and appetite
12
Q
function of exocrine cells
A
secrete substances into lumen that aid digestion
13
Q
function of mucous cells
A
Ducts from accessory organs
14
Q
function of sphincters
A
ring of muscle creating a constriction point which regulates flow, flow is typically mouth to anus but there can be backflow an example being vomit
15
Q
what are the type of sphincters and their location
A
- upper esophageal found between the pharynx and esophagus
2.Lower esophageal found between the esophagus and stomach - pyloric found between the stomach and small intestine
- ileocecal found between the small intestine and the large intestine
- internal anal
- external anal
16
Q
mastication
A
chewing, break down of food by the teeth and facial muscles
17
Q
preparation for swallowing
A
moistening of food bolus from saliva
18
Q
onset of digestion
A
enzymatic breakdown of carbohydrates
19
Q
what is the process of swallowing
A
oral phase: tongue pushes food bolus to the back of the mouth
pharyngeal phase: sift palate elevates to prevent food from entering the nasal passage
epiglottis covers the glottis preventing entry into the trachea the upper esophageal sphincter relaxes
esophageal phase: Food descends the esophagus
20
Q
What is the function of the stomach
A
the stomach stores ingested material, continues digestion and regulates emptying into the small intestine
21
Q
What is happening during Digestion
A
mechanical digestion occurs through the the folded surfaces such as rugae
chemical digestion: HCl provides the acidic environment of the stomach and helps with protein digestion. Pepsin enzyme that breaks down proteins
22
Q
What does ingested food leave the stomach as
A
Chyme
23
Q
The small intestine is spilt into three sections what are they?
A
Duodenum
Jejunum
Ileum
24
Q
What is the primary site of digestion and absorption in the body
A
Small intestine
25
Digestion is aided by what?
aided by hydrolytic enzymes that break down dietary macromolecules
26
Why can the absorption of particles be so efficient
large surface area
27
What does an increase in surface area maximize?
maximize contact between intestinal contents and epithelium, facilitating digestion and absorption
28
What is the function of the large intestine?
store and concentrate undigested material prior to excretion
29
What are the parts of the Large intestine
Cecum
appendix
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
30
what is the function of the appendx
it may act as a haven for gut bacteria
31
what is the function of the cecum
first part of the colon and in herbivores helps with cellulose digestion
32
What is the function of the ascending, transverse, descending and sigmoid colon
absorption of ions, water, bacterial metabolism
33
What is the general function of salivary glands, liver, gallbladder and pancreas
secrete substances into the GI tract that aid in digestion
34
what are the types of salivary glands
parotid salivary gland, sublingual, submandibular
35
What do the salivary glands secrete?
water and mucus
amylase
36
what does the liver secrete?
Bile salts which facilitate fat digestion
Bicarbonate (neutralizes acidic chyme coming from the stomach)
organic waste products and trace metals (eliminated in feces)
37
Where is Bile stored?
Gallbladder
38
What is the Function of the Pancreas
exocrine pancreas is part of the digestive system: Acinar cells secrete into the small intestine via the pancreatic duct
Endocrine pancreas part of the endocrine system: islets of Langerhans secrete hormones into the blood stream
39
what do pancreatic secretions include?
Bicarbonate: acts to neutralize the acidity of Chyme
carbohydrate: pancreatic amalyse
protein: trypsin, chymotrypsin
Fat: Pancreatic lipase
40
what is peristalsis?
travelling wave of contraction that helps push contents of food along
41
What is Segmentation?
more of a mixing function alternating patterns of contraction, formation of individual pockets
42
what does stretch initiate?
initiates circular contraction behind the stimulant, and relaxation in front of it
43
What can reflex response be innervated by?
autonomic input
44
what is the general pattern of peristalsis?
1. Local stretch responses cause release of serotonin
- serotonin activates the myenteric plexus
2. Neurons projecting "upstream" activated and release factors that cause smooth muscle contraction
3. Neurons projecting "downstream" activated and release factors that cause smooth muscle relaxation
45
What is the General patterns of Segmentation?
1. local contractions separate the intestine into pockets
2. subsequent contraction divides pockets centrally
3. rhythmic contractions continue to subdivide pockets mixing their contents
46
What is Basic electrical rhythm (BER)?
Rhythmic contractions of segmentation have their basis in underlaying oscillations in the membrane potential of smooth muscle cells
47
What are the interstitial cells of cajal
Rhythmic activity originates from pacemaker cells which establish the wavelength
48
How is BER modulated?
multiple factors help modulate intestinal motility
ACH increases activity, and simulates contraction
Epinephrine decreases activity and depresses contraction
49
What is the Migrating myoelectric Complex (MMC)?
after a meal has been absorbed, segmentation stops, and is replaced by a sweeping wave of contraction
50
What are the three phases associated with the MMC
phase 1: quiescent period, no activity
phase 2: irregular electrical and mechanical activity
phase 3: burst of regular electrical and mechanical activity
51
What does ingestion of a meal do?
inhibits the MMC
52
what is MMC activity controlled by?
Motilin
53
How does motilin affect the MMC?
increased plasma concentration of motilin triggers MMC
ingestion of a meal inhibits motilin secretion, plasma levels drop and MMCs stop
54
What is the purpose of mastication?
it is a voluntary movement that breaks up large food particles, and mixes the ingested food and aids in swallowing
55
What is the segment-specific motility in the stomach?
1. activity of the lower esophageal sphincter
2. gastric motility, gastric emptying
3. Belching and vomiting
56
Describe the activity of the lower esophageal sphincter?
Tonically active, but relaxes on swallowing to allow entrance of food into the stomach
57
The lower esophageal sphincter contracts in response to _____ and Relaxes in response to _____
Ach,
NO and VIP
58
What are the three major components of the lower esophageal sphincter?
1. internal sphincter- thickening of esophageal smooth muscle
2. External sphincter- crural portion of the diaphragm surrounds the esophagus
59
What is repetitive relaxation?
Arrival of Food Bolus in the stomach
60
When the stomach relaxes the stomach allows ______ in ______ with a marginal increase in _____________
increase in volume with marginal increase in pressure
61
Overfilling of the stomach results in ______
belching or vomiting
62
What is Gastric peristalsis?
mixes the stomach and pushes Food through the Pyloric sphincter?
63
how does Gastric peristalsis happen?
peristaltic wave initiates at upper stomach and increases as the wave moves down the stomach mixing the contents
64
What is Pyloric Sensing?
a small amount if liquid chyme is forced through the pyloric sphincter
65
What type of meals delay gastric emptying?
meals rich in protein or fat
66
What extrinsic factors control gastric emptying?
stomach and intestinal contents
acidity
distension
hypertonicity
67
How does stomach and intestinal contents affect gastric emptying
high fat and high protein meals delay gastric emptying
68
How does acidity affect gastric emptying?
feedback loops exist between stomach and small intestine, exposure of the duodenum to acidity inhibits gastric emptying
69
How does distention affect gastric emptying?
distension increases peristaltic contractions, there fore after a large meal stomach contractions are greater
distension of the duodenum will inhibit gastric emptying
70
how does hypertonicity affect gastric emptying?
gastric emptying is fastest when the duodenal contents are isotonic, a hypertonic solution will inhibit gastric emptying
71
if the duodenum is too hypertonic what does it affect?
water absorption
72
What is aerophagia?
Air unavoidably swallowed during eating and drinking
73
When there is air in the stomach it _____ gastric volume initiating a _______ _____ that ______ the lower esophageal sphincter allowing ______ to escape
increases
reflex response
relaxes
gas
74
What is emesis?
emesis or vomiting is an involuntary forceful expulsion of stomach contents via the mouth
75
What triggers can cause vomiting?
digestive issues such as bowel obstruction or food allergy
Sensory issues like motion sickness, drug reaction
emetics medically administered to prevent poisonings
social cues
76
What are tonic contractions?
relatively prolonged contractions that can isolate segments of the intestine
77
what is the gastrolienal reflex?
opening of the ileocecal valve in response to food leaving the stomach
78
What happens during defecation
increases in rectal pressure caused by mass contraction initiates defecation reflux
79
How do we know we have to defecate?
urge to defecate can be delayed by voluntary contraction of the external anal sphincter
80
What happens can initiated via voluntary straining?
Contraction of Abdominal muscles and relaxation of puborectalis combines to lower the pelvic floor, open the anorectal angle and facilitates defecation
81
How does the body regulate GI processes?
Stimulus, receptor, effector (neural/ hormonal), response
82
What are the four general factors triggering GI response?
1. volume of the luminal contents
2. osmolarity
3. acidity
4. nutrient composition
83
When a stimuli of volume is received it is received on ______ receptor and acts on ____________
mechanoreceptor, Smooth muscle
84
When a stimuli of Osmolarity is received it is received on ______ receptor and acts on ____________
Osmoreceptor, exocrine glands
85
When a stimuli of acidity is received it is received on ______ receptor and acts on ____________
Chemoreceptors, exocrine glands
86
When a stimuli of nutrients is received it is received on ______ receptor and acts on ____________
Chemoreceptors, exocrine glands
87
What are the two types of neural reflex loops?
1. short reflexes
2. long reflexes
88
What is the short reflex loop?
stimulus---> receptor---> nerve plexus----> smooth muscle or gland-----> response
89
What is a long reflex loop?
Stimulus---> sight, smell, taste of food--> central nervous system ( emotional states/hunger) ---->efferent autonomic neurons ----> nerve plexus---> smooth muscle or gland----> response
90
What is hormonal regultion
stimulus---> hormone secretion
91
What is Gastrin
A stomach created hormone which stimulus acid secretion and motility
92
What is CCK? responses?
A small intestine created hormone which inhabits acid secretion and motility in the stomach
stimulates enzyme secretion in the pancreas
simulate contraction of the gallbladder
93
What is secretin? Where is it produced? and what is its responses?
it is a hormone created in the small intestine, that releases when acid is present
in the stomach it inhibits acid secretion and motility
in the pancreas and liver it stimulates HCO3- secretion
94
What is GIP? Where it is produced? and what are its responses
it is a hormone produced in the small intestine, it is triggered when glucose and fat is present.
in the pancreas it stimulates insulin secretion
95
What are the three phases of gastrointestinal regulation?
Cephalic phase, Gastric phase, Intestinal phase
96
What is the Cephalic phase?
sight, smell, taste
97
What is the Gastric phase?
Distension, acidity, amino acids/peptides
98
What is the intestinal phase?
Distention, acidity, osmolarity, digestive products
99
Where do the majority of secretions into the gastrointestinal tract occur?
the accessory glands
100
What are the salivary secretions? and their purpose
there are around 1500mL of secretions released, these include water, electrolytes, mucus (lubrication). enzymes and immune modulators
101
how are salivary secretions regulated?
ANS regulated
Sympathetic N.S: thicker secretion, respiration role, regulated by norepinephrine
Parasympathetic N.S: watery secretion, Digestion role, regulated by Ach
102
What are the Gastric secretions and their functions?
around 2000mL secreted
Mucus- lubricates/protect stomach lining
HCL: solubilizes some food, kills microbes, cleaves pepsinogen
Enzymes: pepsinogen--> pepsin, cleaves proteins
Hormones
103
Where are the Gastric secretions secreted from?
mucus-- surface mucous cells
HCl- parietal cells
Histamine- ECL cell
pepsinogen- Chief cells
104
What are the pancreatic secretions and their function?
about 1500mL secretions
Bicarbonate - acts to neutralize the acidity of chyme
enzymes
105
How is HCO3- regulated
neutralization of intestinal acid provides a negative feedback on secretin stopping its production or limiting it
106
What are the secretions of the Gallbladder? and their function?
daily production aprrox 500mL
Water
Bile salts- solubilize water-insoluble fats
Bilirubin- hemoglobin breakdown, excreted
Fats- includes cholesterol and lecithin; aids digestion
107
When does the gallbladder release bile?
Water and NaCl fare absorbed, making it more concentrated, and in response to CCK, the gallbladder contracts and the sphincter of Oddi relaxes, allowing bile to be secreted in the duodenum
108
What are the intestinal secretions and their functions?
around 1500mL
water/electrolytes: maintains fluidity of intestinal contents
Mucus: lubrication and protection
enzymes: aid digestions
109
Where are the secretions of the intestine occur?
intestinal crypt, when the epithelial cells secrete ions water follows by osmosis
110
how can the osmolarity in the duodenum changes?
Chyme entering, high concentration of solutes = hypertonic environment
osmotic forces drive water from the plasma into the intestinal lumen
111
What is digestion?
process of breaking down large particles of food and high-molecular weight substances into small molecules
112
What are the three macronutrients?
Fats, Carbohydrates, Protein
113
What is the role of carbohydrates?
major energy source, and essential for human tissues
114
what are the types of dietary carbohydrates?
monosaccharides, Disaccharides, Polysaccharides
115
What are types of monosaccharides
simple sugars such as glucose and fructose
116
What are Disaccharides?
composed of two monosaccharides, sucrose, maltose, lactose
lactose==> glucose + galactose
maltose==> glucose+ glucose
117
What are Polysaccharides?
polymers of sugar residues
starch, glycogen
118
What is the role of fat?
Major source of energy, most abundant is triglyceride
119
how is composition of fatty acids affect its physical properties
fatty acyl composition affects the physical properties
this creates saturated fatty acids, mono-unsaturated fatty acids (more fluidity)
poly-unsaturated fatty acids
120
How can you tell the composition of triglycerides?
if it is solid it will be mainly saturated fat 85%, 6% monounsaturated
semi-solid: 56% monosaturated, 29% monounsaturated, 3% polyunsaturated
oil/liquid: 13% saturated, 26% monounsaturated, 59% polyunsaturated
121
What is the function of proteins?
major source of building blocks for numerous biological functions ( new proteins, neurotransmitters)
122
What is the primary structure of a protein?
a linear sequence of amino acids in a polypeptide chain
123
what is the secondary structure of a protein?
structural motifs in the polypeptide chain, alpha-helices and beta pleated sheets
124
What is the tertiary structure of a protein?
three dimensional structure formed by a polypeptide chain
125
What is the quaternary structure of a protein?
complexes with multiple polypeptide chains, hemoglobin
126
What is the supramolecular protein assemblies?
protein complexes, myofilaments, collagen fibers
127
What are micronutrients?
trace amounts of minerals and vitamins to maintain good health
128
What are the fat soluble vitamins?
A, E, D
129
What are trace elements required for a diet?
iron, iodine, zinc
130
How are carbohydrates broken down?
they are broken down from polysaccharides to monosaccharides, and are broken down via their enzymatic breakdown
131
how are carbohydrates broken down in the mouth?
salivary amylase
132
how are carbohydrates broken down the small intestine?
Pancreatic amylase
- soluble protein
cleaves polysaccharides into smaller fragments will cleave between the subunits
Brush border enzymes
- contain many enzymes that are specific to different disaccharides
133
How to carbohydrates get absorbed?
they must cross the intestinal epithelium to be absorbed by the body
134
how does fiber affect the GI tract?
1. delayed gastric emptying and increased satiety
2. impaired absorptions in the small intestine
3. fiber fermentation in the large intestine
4. fecel bulking
135
how are fats digested?
they must be emulsified first and then acted on by lipase enzymes
136
what does emulsification require?
mechanical digestion
emulsifying agents contained in bile: phospholipids and bile salts
137
how can dietary fat be absorbed?
small fraction can be absorbed across the epithelial cell membrane
uptake of fatty across occurs by simple diffusion across a cell membrane (flip-flop)
138
What is protein broken down into?
broken down into amino acids and absorbed
139
how is protein digestion mediated?
by proteolytic enzymes which are secreted as their inactive forms
140
how are protease enzymes classified as?
endopeptidases
exopeptidases
141
What is the function of endopeptidases?
cleave proteins at interior peptide bonds
these can be trypsin, chymotrypsin, elastase
142
what is the function of exopeptidases?
cleave proteins at their n and c termini and are called aminopeptidases and carboxypeptidases
143
What happens when protein enters the stomach?
in the highly acidic environment denatures the protein
pepsin is secreted which cleaves large polypeptides
144
How is protein digested in the small intestine?
pancreatic enzymes and intestinal brush border enzymes
145
how are pancreatic enzymes activated?
through the activity of enterokinase and trypsin
146
why is enterokinase important?
it cleaves trypsinogen to yield trypsin, which actives more trypsinogen in a feed forward loop, and then cleaves other pancreatic proenzymes into their active forms
147
What does intestinal brush border enzymes contain?
aminopeptidases, carboxypeptidases and endopeptidases
148
What do the enzymes in the intestinal brush border do?
generate individual amino acids, dipeptides and tripeptides
149
How does protein absorption occur?
small peptides are taken up into epithelial cells by transport protein called PepT1
once in cell cleaved to amino acids and exit cell via facilitated diffusion
150
majority of water-soluble vitamins are absorbed first into the ___________
small intestine
151
How is Folate absorbed?
folate absorption is dependent on a proton coupled folate transporter
152
How is B12 absorbed?
occurs in the ileum and requires binding to IF
153
for Fat soluble vitamins esters must first be_________ in the gut
Hydrolyzed
154
What is tight regulation of iron absorptions?
the amount taken up matches what is lost. so whole the average iron intake is 20mg only 5% is absorbed
155
Iron is most commonly found in the form of what?
ferric iron
156
What must happen to iron before it can be absorbed? How does this occur?
it must be changed to its ferrous form. a ferric reductase in the brush border epithelium reduces ferric iron to Ferrous iron
157
What allows the uptake of ferrous iron?
DMT1
158
Where is ferrous iron uptake into and what happens once inside?
they are taken into the enterocytes, and some of it is stored and bound to ferritin and the remainder is transported out of the cell and into circulation
159
How is ferrous exported?
exported via the basolateral transporter ferroprotein1
160
What do secretions from the liver facilitate?
digestion and absorption
161
Where do the absorptive segments of the GI tract drain
the hepatic portal vein
162
Where does the liver receive blood from and where does it drain its blood?
it receives blood frim the aorta and through venous drainage via the vena cava
163
What is the hepatic portal vein?
gives blood to liver, from the stomach and intestines
164
Why does the liver receive blood via the hepatic portal system?
substances absorbed in the intestine must pass through the liver and be processed before entering the general circulation system
165
What does the portal triad contain?
portal vein, hepatic artery and Bile duct
166
What is the function of the hepatic artery?
arterial blood flows from the hepatic artery to the central vein oxygenating hepatocytes
167
What is the function of the portal vein?
Blood from the portal vein percolates between the hepatocytes, emptying into the central vein
168
What is the function of the bile duct in regards to the hepatic lobes?
bile produced by the hepatocytes drains into the bile duct
169
Blood travelling through the __________________ can flow through gaps in the ______________________ entering the space of _________ to come into direct contact with ______________
hepatic sinusoids, endothelial cell layer, Disse, Hepatocytes
170
Why is lobule (liver) organization important?
it creates a graded microenvironment that leads to zonation of the hepatic metabolism
171
On the P-C axis the cells closet to the central vein control what?
glycolysis, bile acid production, glutamine synthesis, xenobiotic metabolism
172
On the P-C axis the cells closet to the portal tract do what?
gluconeogenesis, beta-oxidation, cholesterol biosynthesis, Ureagenesis and protein secretion
173
On the P-C axis the cells in between the central vein and portal tract do what?
Iron homeostasis, Modulation of insulin growth factors
174
What does drug overdose cause?
toxic metabolite accumulation and damage in the pericentral zone
175
What does cholangitis damage?
the periportal zone
176
What is the livers role in carbohydrate metabolism?
it uptakes and stores glucose through glycogenesis and stores it as glycogen
it can release glucose when blood sugar drops through Glycogenolysis
and it can synthesize glucose through gluconeogenesis
177
What is the Livers role in lipid metabolism?
1. it can store fatty acids as triglycerides
2. it can cleave fatty acids through beta-oxidation( energy production)
3. De novo lipogenesis to create more fatty acids when glucose is high
4. lipoprotein secretion
178
What is non-alcoholic fatty livre disease?
secondary to obesity, where the liver becomes fatty
179
Where is vitamin A stored?
in liver specifically in the hepatic stellate cells
180
Hepatocytes express detoxifying enzymes what are they and what do they do?
they express CYPs which mainly detoxify xenobiotics and toxins primarily through oxidation
181
What is the most common reaction catalyzed by CYPs?
mono-oxygenase reaction
182
How is alcohol metabolized?
Ethanol ---CYP2E1----> Acetaldehyde
183
When you have to take a medication such as acetaminophen what normally happens? and what happens when you mix it with alcohol?
normally it will go through Glucoronidation leading to stable metabolite excretion
how ever when mixed with alcohol CYP2E1 reacts causes a toxic metabolite
184
Why must ammonia be tightly regulated and detoxified by the liver?
it is membrane permeable and is toxic to the central nervous system
185
how is ammonia metabolized?
within a hepatocyte mitochondria ammonia is metabolized to urea
186
Why can the liver regenerate its self?
because its role is to detoxify the liver can become damaged and therefore regenerate its self
187
What is Fatty liver disease?
it is the first stage of liver disease and its deposits of fat can lead to liver enlargement
this is seen throughfibrous portal expansion
188
What is liver Fibrosis?
scar tissue formation, intralobular degeneration
189
What is Cirrhosis?
Growth of connective tissue destroys liver cells.
190
What are the roles of bile?
central role is in digestion and absorption but also facilitates the excretion of lipid soluble waste products into the feces
191
Where is bile secreted from?
the hepatocyte into the bile canaliculi which drains into the bile duct
192
What is enterohepatic circulation?
liver secretes about 500mL of bile a day much of which is reabsorbed into the intestine and then excreted again
193
why does bile have yellow-green colouration?
due to the presence of bilirubin and biliverdin
194
What are bilirubin and biliverdin products of?
products of hemoglobin catabolism, which are continually produced in the liver and spleen when old/damaged red blood cells are broken down
195
when circulating bilirubin is bound to albumin it can be taken up by the _______ and metabolized into ________ ______
hepatocytes, bilirubin glucuronide
196
What is Bilirubin glucuronide?
it is a highly water soluble molecule which can be transported into the bile canaliculi for secretion
197
What is jaundice?
caused when bilirubin accumulates in the blood
198
What are the origins of jaundice?
pre-haptic origin (increased RBC breakdown), hepatic origin (liver disease) or post-hepatic (obstruction of bile seertion)
199
What can hyperbilirubinemia lead to?
leads to bilirubin accumulation in the CNS causing brain damage
200
what is neonatal jaundice caused by?
associated with the breakdown of fetal hemoglobin and delayed maturation of metabolic pathways in the liver
treated via phototherapy
201
Why does the stomach not digest itself?
in the gastric lumen you have pepsinogen and pepsin which interact with the mucous bicarbonate barrier which neutralizes the acidity of the stomach.
202
How is the stomach protected?
stomach lining is protected from proteolytic enzymes and acidic contents by alkaline mucus, tight junctions and turnover of damaged cells
203
What happens when the the mucosal barrier breaksdown?
can lead to erosin of gastric epithelium and ulcer formation
204
What is the main cause of stomach ulcers?
the bacterium Helicobacter pylori
205
How can stomach ulcers be identified?
medical history and physical
laboratory test for H.Pylori
endoscopy
barium meal
206
What is the treatment for stomach ulcers?
antibiotics
neutralization of stomach acids
Inhibition of stomach acid
- Histamine blockers-block specific histamine receptor
-proton pump inhibiotrs
207
What are the two types of gall stones?
cholesterol
calcium bilirubinate
208
How do cholesterol stones develop?
cholesterol stones develop when concentration of cholesterol in the bile increases to the point where it precipitates out of solution
209
How can Biliary cholesterol increase?
can result from increased hepatic secretion of cholesterol or too much ion and water absorption
210
Small Gallstones that form in the gallbladder can what?
be easily passed into the intestine and excreted
211
Larger gallstones can cause what?
larger stones may be trapped leaving the gallbladder, causing pain however digestion is largely unaffected
212
When larger stones get trapped in the bile duct what can happen?
may cause consequences with fat digestion/absorption, causing diarrhea. this can also cause backflow, and decrease bilirubin excretion and cause obstructive jaundice
213
When larger gallstones get trapped in ampulla of vater what can happen?
this will block bile and pancreatic secretions, and may cause problems with nutrient digestion/absorption and cause nutritional deficiency
214
How can gallstones be diagnosed?
Medical history
ultrasound
Ct scan
215
How can gallstones be treated?
medication such as ursodiol
surgical removal of the gallbladder
216
What is colitis?
inflammation of the inner lining of the colon
217
What are the symptoms of colitis?
abdominal pain, cramping
diarrhea
218
What can cause colitis?
infection
IBS
ischemia
219
Clostridium difficle is a bacteria which can cause colitis which type can it cause?
health associated infective diarrhea also known as community acquired colitis
220
what can be some symptoms associated with a c.diff infection?
self -limiting diarrhea--> fulminant colitis--> pseudomembranous colitis ----> toxic megacolon --> bowel perforation and sepsis---> multiple organ dysfunction syndrome
221
How can C.diff be treated?
1.antibiotic therapy
pro: effectively targets C.diff
Con: antibiotic resistance
2. Fecal microbiota transplant
222
