GI Flashcards
What causes stomatitis?
Poor oral hygiene, dietary protein insufficiency, poorly fitted dentures, burns from hot food, allergies, conditions affecting the whole body
Where can candida be found
Mouth + esophagus
What 2 things are needed for the LES to function properly?
Inner circular esophageal muscle Surrounded by a loop of diaphragmatic muscle
Why does the LES not work well when there is a Hiatal Hernia?
Because part of its function depends upon the diaphragm circling around it
What structure drains the foregut, midgut and hindgut?
Portal vein
Cirrhosis causes portal HTN, what is the significance of this condition?
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
What drains the majority of the esophagus?
Hemiazygous and azygous v.v.
What drains the cervical region of the esophagus?
inferior Thyroid v
What happens in esophageal varices?
HTN from backed up portal vein flowing into azygous and hemiazygous v.v. These veins can rupture and bleed. 33% mortality; 50% recurrances
Tx for esophageal varices
*shunting *banding and sclerotherapy for mild cases 90% effectiveness *vasopressin
The Vagus nerve has been surgically cut (ligated) in the past before it’s function was fully understood. Why did we do this?
The Vagus nerve releases Ach in the stomach, and the stomach in turn produces HCl
If someone had ulcers that could not be treated in any other way, the nerve would be cut…
stopping the release of Ach and thus stopping acid production
What is stomatitis?
Inflammation of any of the structures of the mouth, including the buccal mucosa, gums, tongue, throat, lips, or palate
Why do esophageal cancers metastasize so quickly?
No serosa
The Vagus nerve has been surgically cut (ligated) in the past before it’s function was fully understood. Why did we do this?
The Vagus nerve releases Ach in the stomach, and the stomach in turn produces HCl
Is the vagus primarily a sensory or motor nerve?
Sensory
What cell type normally lines the esophagus?
Stratified Squamous epithelium
why are most esophageal cancers NOT SCC (squamous cell carcinoma)?
Intestinal metaplasia occurring in invading columnar epithelium for the stomach causes Barrett’s esophagus and thus adenocarcinoma
How can having a hiatus hernia ultimately lead to cancer?
Acid reflux leads to intestinal metaplasia (influx of columnar epithelium from the stomach)
What structure causes the plica circulares to form?
Muscularis mucosa
What layer houses the glands?
Submucosa
What are 2 muscle layers in most of GI
Inner circular, outer longitudinal
What are the histo logical layers in most of GI? Lumen –> serosa
Mucosa *epithelium *lamina propria *muscularis mucosa Submucosa Muscularis Externis Serosa
What is the blood supply to the foregut, midgut and hindgut?
Celiac, Superior Mesenteric, Inferior Mesenteric Arteries
Which Vagus nerve can be seen on the anterior surface of the stomach?
Clockwise rotation makes the left branch of the Vagus anterior
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
Why is the greater omentum important?
Walls off inflammatory processes in the abdomen
What artery comes off the aorta cephalad to the pancreas?
Celiac
What is the first major artery to come off caudad to the body of the pancreas from the aorta?
superior mesenteric artery
Why is the antrum of the stomach sometimes removed, and where is it located?
Intractable peptic ulcer disease initial part of the pylorus
Where is the pylorus and what does it do?
Valve separating the stomach from the duodenum
What do flattened rugae indicate?
If the rugae, folds, are flattened, it may indicate stomach inflammation (gastritis)
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
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.
What is the classic metabolic disturbance in pyloric stenosis and why?
loss of HCl (along with K+) from persistent vomitting –> metabolic alkalosis hypokalemia hypochloremic
if you see an ulcer at location V, what location is this and what is associated with causing it?
Body of the stomach NSAIDs
Type I: Ulcer
along the body of the stomach Not associated with acid hyper secretion; associated w/ Type A blood
Type II: Ulcer
in the body in combination with duodenal ulcers. Associated with acid oversecretion.
Type III: ulcer
In the pyloric channel within 3 cm of pylorus. Associated with acid oversecretion
Type IV: ulcer
Proximal gastroesophageal ulcer
what ulcers are type O blood associated with?
II-IV
Where is iron absorbed?
duodenum
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
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
When does pancreatic adenocarcinoma occur in most people and what are the symptoms?
50s-60s Pain radiating to the spine
Why are most cases of pancreatic adenocarcinoma inoperable?
The tumor has encased the SMA and SMV
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)
What structure connects the GI capillary beds to the liver sinusoids?
Portal Vein
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
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
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.
The midgut and hindgut leave the abdomen during what week of development?
5
The midgut and hindgut return the abdomen during what week of development?
10
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
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
ascending and transverse colon are supplied by what arteries
ileocolic, R & middle colic arteries
What is the fuel used by enterocytes?
glutamine
What is the fuel used by colonocytes?
Short-chained fatty acids
How does the vascular pattern differentiate the ilium from the jejunum?
ileum–branched or multiple vascular vascular arcades
jejunum–straight vascular arcades
What structures run in the mesentery?
Arteries, veins and lymphatic structures
Where does the SMA insert?
The posterior aspect of the hollow viscera
(The Mesenteric Boarder)
What branches of the SMA supply the ascending and transverse colon?
iliocolic, right colic, and middle colic arteries
