GI Flashcards
(158 cards)
1
Q
What causes stomatitis?
A
Poor oral hygiene, dietary protein insufficiency, poorly fitted dentures, burns from hot food, allergies, conditions affecting the whole body
2
Q
Where can candida be found
A
Mouth + esophagus
3
Q
What 2 things are needed for the LES to function properly?
A
Inner circular esophageal muscle Surrounded by a loop of diaphragmatic muscle
4
Q
Why does the LES not work well when there is a Hiatal Hernia?
A
Because part of its function depends upon the diaphragm circling around it
5
Q
What structure drains the foregut, midgut and hindgut?
A
Portal vein
6
Q
Cirrhosis causes portal HTN, what is the significance of this condition?
A
Blood cant get through the liver effectively, so it shunts it through the Azygous and Hemiazygous veins in order to get it back to the heart Blood backs up into other structures like the esophageal veins, this causes esophageal varices
7
Q
What drains the majority of the esophagus?
A
Hemiazygous and azygous v.v.
8
Q
What drains the cervical region of the esophagus?
A
inferior Thyroid v
9
Q
What happens in esophageal varices?
A
HTN from backed up portal vein flowing into azygous and hemiazygous v.v. These veins can rupture and bleed. 33% mortality; 50% recurrances
10
Q
Tx for esophageal varices
A
*shunting *banding and sclerotherapy for mild cases 90% effectiveness *vasopressin
11
Q
The Vagus nerve has been surgically cut (ligated) in the past before it’s function was fully understood. Why did we do this?
A
The Vagus nerve releases Ach in the stomach, and the stomach in turn produces HCl
12
Q
If someone had ulcers that could not be treated in any other way, the nerve would be cut…
A
stopping the release of Ach and thus stopping acid production
13
Q
What is stomatitis?
A
Inflammation of any of the structures of the mouth, including the buccal mucosa, gums, tongue, throat, lips, or palate
14
Q
Why do esophageal cancers metastasize so quickly?
A
No serosa
15
Q
The Vagus nerve has been surgically cut (ligated) in the past before it’s function was fully understood. Why did we do this?
A
The Vagus nerve releases Ach in the stomach, and the stomach in turn produces HCl
16
Q
Is the vagus primarily a sensory or motor nerve?
A
Sensory
17
Q
What cell type normally lines the esophagus?
A
Stratified Squamous epithelium
18
Q
why are most esophageal cancers NOT SCC (squamous cell carcinoma)?
A
Intestinal metaplasia occurring in invading columnar epithelium for the stomach causes Barrett’s esophagus and thus adenocarcinoma
19
Q
How can having a hiatus hernia ultimately lead to cancer?
A
Acid reflux leads to intestinal metaplasia (influx of columnar epithelium from the stomach)
20
Q
What structure causes the plica circulares to form?
A
Muscularis mucosa
21
Q
What layer houses the glands?
A
Submucosa
22
Q
What are 2 muscle layers in most of GI
A
Inner circular, outer longitudinal
23
Q
What are the histo logical layers in most of GI? Lumen –> serosa
A
Mucosa *epithelium *lamina propria *muscularis mucosa Submucosa Muscularis Externis Serosa
24
Q
What is the blood supply to the foregut, midgut and hindgut?
A
Celiac, Superior Mesenteric, Inferior Mesenteric Arteries
25
Which Vagus nerve can be seen on the anterior surface of the stomach?
Clockwise rotation makes the left branch of the Vagus anterior
26
Which divisions of the gut have both dorsal and ventral mesogastrium?
Note that the foregut is the only place where the structures are tethered both dorsal and ventral by their respective mesogastrium
27
Why is the greater omentum important?
Walls off inflammatory processes in the abdomen
28
What artery comes off the aorta cephalad to the pancreas?
Celiac
29
What is the first major artery to come off caudad to the body of the pancreas from the aorta?
superior mesenteric artery
30
Why is the antrum of the stomach sometimes removed, and where is it located?
Intractable peptic ulcer disease initial part of the pylorus
31
Where is the pylorus and what does it do?
Valve separating the stomach from the duodenum
32
What do flattened rugae indicate?
If the rugae, folds, are flattened, it may indicate stomach inflammation (gastritis)
33
Why do babies with pyloric stenosis have Non-bilious vomiting?
Bile is released by the common bile duct in the duodenum, so the bile cannot get backwashed into the stomach, as the enlarged pylorus prevents this
34
pyloric stenosis
condition that causes non-bilious projectile vomiting in the first 2-6 weeks of life. more common in first born males. result of an olive shaped mass (congenital or hypertrophy) in middle upper or upper right quadrant that narrows the pyloric sphincter.
35
What is the classic metabolic disturbance in pyloric stenosis and why?
loss of HCl (along with K+) from persistent vomitting --\> metabolic alkalosis hypokalemia hypochloremic
36
if you see an ulcer at location V, what location is this and what is associated with causing it?
Body of the stomach NSAIDs
37
Type I: Ulcer
along the body of the stomach Not associated with acid hyper secretion; associated w/ Type A blood
38
Type II: Ulcer
in the body in combination with duodenal ulcers. Associated with acid oversecretion.
39
Type III: ulcer
In the pyloric channel within 3 cm of pylorus. Associated with acid oversecretion
40
Type IV: ulcer
Proximal gastroesophageal ulcer
41
what ulcers are type O blood associated with?
II-IV
42
Where is iron absorbed?
duodenum
43
Where does the foregut end?
The foregut ends after the first portion of the duodenum, a location when the bile and pancreatic ducts drain into the duodenum
44
Why do anterior duodenal ulcers perforate and posterior duodenal ulcers bleed?
Anterior ulcers perforate the diaphragm causing pneumoperotonium The largest arterial supply generally comes from the posterior surface of a hollow viscus (intestines and stomach) Gastroduodenal artery runs on the posterior surface of the duodenum
45
When does pancreatic adenocarcinoma occur in most people and what are the symptoms?
50s-60s Pain radiating to the spine
46
Why are most cases of pancreatic adenocarcinoma inoperable?
The tumor has encased the SMA and SMV
47
What is the outlook for pancreatic adenocarcinoma?
20% 5 yr. Survival rate with resection 50% invade portal vein, SMV or retroperitoneum at time of diagnosis (unresectable disease)
48
What structure connects the GI capillary beds to the liver sinusoids?
Portal Vein
49
Major GI veins
splenic--spleen and stomach superior mesenteric---sm intestine, cecum, ascending colon, transverse colon inferior mesenteric--transverse and descending colon, rectum, anal canal
50
Why doesn't a persons “gut’s” spill out onto the floor when they are attacked and eviscerated by a ninja?
The midgut and hindgut are tethered by the dorsal mesogastrium AKA the Unlike with the stomach and 1st portion of mesentary the duodenum, these structures are not connected by a ventral mesogastrium
51
Mesentery
Portion of dorsal mesogastrium that spans between the posterior wall and the small and large intestines. Lack of a ventral portion permits intestines to move freely within abdominal cavity.
52
The midgut and hindgut leave the abdomen during what week of development?
5
53
The midgut and hindgut return the abdomen during what week of development?
10
54
Why do the midgut and hindgut leave the abdomen during development?
Gives the abdomen time to enlarge and allows them to move around so that they can rotate 270
55
Why is knowing the arterial branches of the midgut important?
It tells the surgeon where to resect, as resection is done to include everything perfused by the artery and veins where the primary tumor is located (in order to get the LN (lymph nodes) that may be harboring cancer
56
ascending and transverse colon are supplied by what arteries
ileocolic, R & middle colic arteries
57
What is the fuel used by enterocytes?
glutamine
58
What is the fuel used by colonocytes?
Short-chained fatty acids
59
How does the vascular pattern differentiate the ilium from the jejunum?
ileum--branched or multiple vascular vascular arcades
jejunum--straight vascular arcades
60
61
What structures run in the mesentery?
Arteries, veins and lymphatic structures
62
Where does the SMA insert?
The posterior aspect of the hollow viscera
(The Mesenteric Boarder)
63
What branches of the SMA supply the ascending and transverse colon?
iliocolic, right colic, and middle colic arteries
64
What allows the sm intestine to absorb so much food?
Plica--\>villi--\>microvilli
65
microvilli
projections of enterocyte cell membranes into the lumen; also called the brush border.
66
Why is it bad sometimes for lymphatic drainage if a person gets stabbed in the left neck?
Thoracic duct empties into the junction of the left subclavian and internal carotid vein
67
What structure in a villi marks the beginning of the lymphatic collection system in the GI tract?
The Lacteal
68
Thoracic Duct ascends along ??? & drains into the ???
ascends along vertebral column & drains into the junction of left internal jugular and subclavian vein
69
Cisterna Chyli
diliated lymphatic vesslel taht receives lymph from several areas of the GI tract and abdomen
70
Intestinal Malrotation
This is what happens if the gut does not rotate 270 degrees
71
what does intestinal malrotation cause?
bowel obstruction
72
What is the clinical significance of Ladd's Bands?
series of bands crossing the duodenum that can cause bowel obstruction
73
bilious vomitting in babies can indicate
intestinal malrotation
74
What happens if the Vitelline duct does not obliterate (3)
Meckel’s diverticula Vitelline cyst
ophalmocele
75
Why does Meckel’s sometimes bleed
Has gastric tissue in it that responds to circulating blood gastrin and subsequently produces HCl, which erodes the intestinal wall
76
What is the most common
malformation of the GI tract?
Meckel’s
77
What are the characteristics of Meckel's Diverticulum?
\* small bulgein the sm intestine
\*bleeing may only start in adulthood
\*antimesenteric border of the small bowel
78
Where is Meckel’s found?
The anterior or antimesenteric boarder
79
What is the #1 cause of painless GI bleeding in children?
Meckel's Diverticulum
80
What 4 conditions can occur if the vitelline duct fails to completely close?
meckel's diverticulum
viteline cyst
vitelline fistula
omphalocoele
81
classic symptom is Currant jelly stools (from vascular congestion)
intussusception
82
What is intussusception?
Telescoping of one segment of intestine into another
83
What does it mean when it says that there is a “lead point” in intussusception ?
Usually a swelling that leads the telescoping segment into the other
84
in intussusception,
## Footnote
What is the most common lead point for a child?
How about an adult?
For children, the lead point is often a swollen lymph
node, for an adult it is often a tumor
85
What is the most common cause of small bowel obstruction?
Intra-abdominal adhesions
86
What is the most common cause of large bowel obstruction?
Cancer
87
What major vessel supplies the hindgut?
Inferior Messenteric Artery
88
What are the minor branches of the IMA? What do they supply?
left colic--left colic flexure + some transverse colon
sigmoid branches--sigmoid colon
superior rectal--rectum
89
What is the function or consequence of Tenia Coli?
Being shorter than the underlying viscus, they create Haustra and attachment points for structures
90
What are the divisions of the large intestine?
Ascending colon, transverse colon, descending colon
Sigmoid colon
Rectum
Anal canal
91
Why is the sigmoid colon’s “floppiness” clinically important?
The sigmoid colon is floppy, so diseases there can appear to be on the right side since it can flip over to that side even though the sigmoid is on the left
92
What is the underlying problem that causes Hirschsprung’s disease?
the failure of the neural crest cells (ganglion cells) to progress in craniocaudal direction
93
Hirschsprung’s disease symptoms
newborns
## Footnote
green or brown vomit
explosive stools after a doctor inserts a finger into the rectum
swelling of the belly, also known as the abdomen
lots of gas
bloody diarrhea
94
What layers are missing in
“diverticular disease”?
Muscular layers
95
How do a true and false diverticula differ
True has muscle layers and usually occurs on the right side of the colon, is congenital not acquired, and is more common in asians
96
Diverticulitis
v.
Diverticulosis
Diverticulitis in inflammation, usually from infection, occurring in a diverticula
Diverticulosis is the presence of several diverticuli
97
What structure is missing in the appendix?
Villi
98
What are the characteristics of Crohn’s disease?
skip lesions
can involve anus
fissures
bleeding absent ~30% of time
99
What are the characteristics of Ulcerative colitis v. crohns?
UC always has bloody diarrhea, Crohn's about 70% of the time
100
ulcerative colitis characteristics
bloody diarrhea
abdominal pain
fever
weight loss
involves mucosa and submucosa
fistulas and strictures rare
spares anus
mucosal involvement contiguous
101
What plexus do hemorrhoids form in?
Both the internal rectal venous plexus, and the inferior rectal venous plexus
102
What plexus to suppositories take advantage of for absorption in hemorrhoid Tx?
Internal rectal venous plexus
(Not the inferior rectal venous plexus)
103
merocrine secretion
products in membrane bound vescicles fuse with the cell membrane and secrete via exocytosis
104
apocrine secretion
product plus some cytoplasm is released wrapped in cell membrane.
common in skin
\*double check slide\*
105
holocrine secretions
whole cell undergoes apoptosis and secretes product and cell debris
(sebacous gland of skin)
106
duct
cylinders of cells that convey saliva and secrete various proteins and electrolytes
107
acinus
spherical structure of secretory mucus/serous cells
108
serous cells secrete
digestive enzymes
109
goblet cells secrete
mucin, from glycoproteins
110
myoepithelial cells
surround and contract the acinar cells to promote salivary flow
111
why can chronic stress cause cavities
a more active sympathetic system increases the protein to fluid ratio and decreases the alkalizing components of the saliva like bicarbonate.
There also MAY be less bactericidal agents in sympathetic secretions
112
relative composition of different salivary gland products
parotid--watery saliva
sublinguial--mucin
submandibular--mixture
113
Why do you salivate so much when you vomit?
nausea induces saliva in anticipation of neutralizing the stomach acid
114
parietal cells secrete
HCl
intrinsic factor (increases Ca++ absorption)
115
mucous neck cell secretes
mucus
bicarbonate
116
enterochoraffin-like cell secretes
histamine to stimulate acid
117
chief cells secrete
pepsinogen
gastric lipase
118
g cell secretes
gastrin
119
d cell secretes
somatostatin
120
mucus cell secretes
mucus
121
somatostatin
inhibits gastrin release
122
gastrin
leads to the release of acid from pareital cells
123
describe the digestion cascade
vagus n fires
release Ach
--\>G cells
secrete gastrin
--\>pareital cells
secrete HCl
cleaves pepsinogen
pepsin breaks down proteins
124
how is the release of HCO3 triggered
when HCL is released,
the acidity causes goblet cells to release mucus
this leads to the release of bicarb
125
describe the histamine cascade
HCl
g cells
gastrin
ECL cells
histamine
--\> A. chief cells/pepsinogen
B. pareital cells/HCl
126
what cells in the stomach have the most important protein pump?
pareital cells--necessary for facilitated transport of HCl release
127
in para- or sympathetic state do cells "want" glucose
sympathetic
128
glucose homeostasis should be b/w
70-110 units
129
glucagon -- blood glucose levels
raises
130
insulin -- blood glucose
lowers
131
SST is a product of
product of D cells in antrum and Delta cells in pancreas
132
what does pancreatic secretions of somatostatin do?
inhibits release of glucagon and insulin
133
how does glucagon act on the liver to increase glucose secretion and production
glycenolysis
gluconeogenesis
134
insulin function
primary regulator of carbohydrate and fat metabolism and storage
135
multiple actions of the insulin receptor (4)
1. glucose uptake into the cels
2. protein, fat, and glycogen synthesis
3. growth and gene expression
4. satiety signal
136
describe the facilitation of glucose uptake via GLUT-4 transporters
glucose enters adipose and muscle cells via GLUT-4 transporters
insulin receptors trigger the translocation of GLUT4 transporter into the cell membrane
137
pancreatic alpha cells secrete
glucagon
138
pancreatic beta cells secrete
insulin
139
how does insulin promote glycogen storage?
activates glycogen synthase
inhibits glycogen phosphorylase
140
how is insulin secretion regulated by glucose levels?
incoming glucose stimulates glycolysis
--\>ATP
--\>K+ channel closes
--\>Ca++ released
--\>stimulates release of insulin (via synaptic transmission)
141
what stimulates glucagon release?
low glucose
AAs
ACh, Epi, NE
142
what inhibits glucagon release?
high glucse
insulin
fatty acids
sommatostatin
143
role of SST
paracrine release from delta cells
inhibits secretion of glucagon and insulin
prevents rapid nutrient exhaustion
144
what stimulates pancreatic SST release?
hyperglycemia, glucagon, amino acids
145
symptoms from Type I diabetes
hyperglycemia: excessive hunger, excessive thirst, frequent urination, weight loss, fatigue, weakness, irritability, blurry vision
146
symptoms of Type II diabetes
symptoms: excessive hunger/thirst, increased urine volume, weight loss, fatigue, recurrent infections, changes in vision, tingling/prickling sensations in skin
147
is a patient with DM I or II more likely to experience Diabetic ketoacidosis
II but I is more serious when it happens
148
what inhibits insulin secretion
NE, epi
SST
149
what stimulates insulin secretion
growth hormone and cortisol
certain AAs
ACh
endocrines secreted from the stomach--CCK, GLP-1, GOP
150
Endopeptidase
is an enzyme that cleaves a molecule in the middle
151
Enteropeptidase or enterokinase
is an endopeptidase that cleaves a short series of oligopeptides from trypsinogen which leads to activation
152
Aminopeptidase
153
Most proteins are denatured where
154
GLUT 2
GLUT 2 help enterocytes, liver, and pancreas cells uptake glucose. It has a lower affinity but higher capacity which means that it will only uptake small amounts of glucose in normal situations BUT it is capable of storing glucose when there are small amounts present within the blood.
155
Remember role of mothers passing on X to promote the growth of X in infants
oligosaccharides
Bifidobacterium
156
If fibers produce a gel then things will be digested more [slowly/faster]?
slowly
157
insulin doesn’t alter the rate at which glucose enters the brain because
the brain uses GLUT 1 transporters
158
