GI Flashcards
what double fold of peritoneum connects the stomach to the liver
lesser momentum
double fold of peritoneum
what does the gastro-colic ligament connect
connects greater cure of the stomach to the transverse colon
what does the falciform ligament connect
falciform ligament connects liver to the ant abdomen wall
what path does a direct inguinal hernia follow as it leaves the abdomen?
through a weakness in Hesselbach’s triangle
- medial to inferior epigastric vessels
what gastric secretion can be considered part of the innate immune system
hydrochloric acid
- kills bacterial as they enter the stomach= chemical barrier to pathogens
define the pharyngeal phase
- involuntary
- soft palate seals off nasopharynx
- pharyngeal constrictors push bolus down
- larynx elevates, closing epiglottis
- vocal cords adduct and breathing temporarily ceases
- opening of upper oesophageal sphincter
an abdominal wall hernia can enter the inguinal canal by passing through a defect in which structure?
- transversalis fascia
to enter the inguinal ligament a hernia must enter the inguinal canal through the deep inguinal ring which is a defect in the transvarsalis fascia
what happens to the conc of bicarbonate ions at higher flow rates of saliva?
increase
- different to the other ions in saliva, where a higher flow rate results in less movement across the ductal cells ( less ductal modification)
a femoral hernia protrudes through the femoral ring and down the femoral canal. what forms the lateral border of the femoral ring?
femoral vein
- the empty space in the femoral canal and at the top of the femoral canal is the femoral ring
therefore: NAVEL
medially: lacunar ligament
anteriorly: inguinal ligament
posteriorly: pectineal ligament
where in the abdomen might a patient complain of pain if there was a problem with their jejunum?
peri-umbilical area
- jejunum part of midgut
- viscaeral afferent nerves follow the sympathetic supple back to the spinal cord. lesser splanchnic nerve T10-11 -> dermatome is peri-umbilical.
foregut: epigastric area
midgut: peri-umbilical area
hindgut: suprapubic area
which viscera has a blood supply derived from both the foregot and midgut?
pancreas
develops on the junction of the foregut and midgut
the superficial ring of the inguinal canal pierces the aponeurosis of which muscle?
external oblique
non-steroidal anti-inflammatory medications (NSAIDs) are known to increase the risk of peptic ulceration. what is the mechanism by which they promote epithelial damage?
reduce gastric prostaglandin synthesis
during embryological development the entire gut tube is suspended by a dorsal mesentery. which part of the developing gut tube also has a ventral mesentery?
foregut
- the liver develops within this ventral mesentery
what are the temporary folds of the stomach called?
rugae
- disappear when the stomach fills
stomach acid produced is under neural, paracrine and endocrine control. what is involved in the paracrine control of stomach acid production?
histamine
- released from ECL cells and acts locally to stimulate the parietal cells to produce acid
during development of the gut, the midgut loop is connected to the yolk sac via which structure?
vitelline duct
-
in the pharyngeal phase of swallowing, what structures help prevent reflux of food into the naso-pharynx
soft palate
how is the tonicity of saliva described as?
hypotonic
what is the location of the linea alba?
vertical in the midline from xiphoid process to pubic symphysis
which artery is at risk from an ulcer that perforates through the body of the stomach?
splenic artery
the term ‘cranio- sacral outflow’ relates to which part of the nerve supply to the gut?
parasympathetic nervous system
during embryological development of the gut, which artery forms the axis of the midgut loop that herniates?
SMA forms the axis
SMA remains the arterial blood supply for the midgut derivates
what section of the GI tract is the appendix located?
caecum
- start of the large intestine
- caecum is a large bulge in the GI tract that follows on from the end of the ileum (terminal ileum)
what is the major function of the colon
water reabsorption
- most of the water has already been absorbed by the small intestine
what section of the GI tract follows on from the descending colon?
sigmoid colon
- found in LLQ
what causes the ‘alkaline tide’ following a meal?
movement of HCO3 across the basolateral membrane
- pH of blood increases
what provides the liver with its greatest structural support with the abdo cavity?
IVC
- via connection of hepatic veins
how does the stomach physically disrupt food?
muscular contractions of the antrum
- antrum has much thicker muscular walls
where in the GI tract will you find stratified squamous epithelia
distal anal canal
- most of gut lined with simple columnar epithelium
vague (midline) supra pulic abdo pain could indicate a problem in which part of the GI tract?
sigmoid colon
- hindgut
what specialised cells in the stomach are responsible for the secretion of pepsinogen?
chief cells
where in the GI tract are digestive enzymes first secreted and what are they
oral cavity
salivary amylase and lipase
where do the majority of digestive enzymes enter the gastro-intestinal tract?
majority produced by the pancreas and released into the duodenum
what is an Omphalocele?
- physiologically herniated midgut structure fails to return to the abdo cavity during development
- viscera persists outside the abdo cavity at birth within the umbilical ring- covered in a layer of peritoneum
- not directly exposed to amniotic fluid and can develop normally
where in the gut wall is Meissner’s plexus found?
submucosa
the other plexus- Auerbach’s is found between the inner circular and outer longitudinal muscles of the muscular propria
what structure forms the floor of the inguinal canal
inguinal ligament
where do the parasympathetic pre-gangiolic fibres synapse in the gut?
visceral wall ( of the innervated viscera) short post- ganglionic fibre sits within the wall of the viscera
what type of jaundice gives you unconjugated hyperbilirubinaemia?
pre-hepatic
which cells located at the base of the intestinal crypts produce antimicrobial peptides that protect the surrounding cells
Paneth cells
- produces large amounts of alpha- defensins and other antimicrobial peptides
what molecules are produced when amylase breaks down the amylopectin component of starch?
alpha- dextrin
which membrane transporter facilitates the absorption of fructose into the enterocyte
GLUT5
which protease enzyme released by the pancreas helps to convert other proteases into their active forms?
trypsin
- trypsinogen is released from the pancreas and when it is in the gut lumen another enzyme enteropeptidase (enterokinase) converts it into its active form trypsin
trypsin then converts the other pro-enzymes into their active forms
what is the basis of lactose intolerance
inability to break down lactose into monosaccharides
- insufficient lactase in the brush border of the enterocyte
which stage of alcoholic liver disease does not give you hepatomegaly?
cirrhosis
- fatty change and hepatitis cause liver enlargement and both of these stages are reversible
how does cholecystitis differ from biliary colic?
presence of inflammation
- acute cholecystitis can follow on from biliary colic if the gallstone gets impacted in the cystic duct
- biliary colic is pain related to the temporary presence of a stone in the cystic duct, where cholecystitis is inflammation of the gallbladder
a gallstone lodged in which location within the biliary tree can cause acute cholecystitis
cystic duct of the gallbladder
- cause pain and inflammation
a gallstone lodged in which location within the biliary tree could potentially cause pancreatitis?
pancreatic duct (into duodenum)
during an endoscope an ulcer is found in the stomach. which part of the stomach is particularly prone to ulceration?
lesser curve of the stomach
- overall the most common location for peptic ulceration is the first part of the duodenum
if a gastric ulcer were to erode through the posterior aspect of the body of the stomach, which major artery might be at risk from haemorrhage?
splenic artery
severe abdo pain and diarrhoea
severe gastric ulceration that extends into the small intestine
a diagnosis of Zollinger Ellison syndrome is made
what hormone is released in excess in ZES?
cholecystokinin
- non beta cell gastrin secreting tumour of the pancreas releases excessive gastrin
- encourages the proliferation of parietal cells and a resultant excess secretion of stomach acid
what blood test result when raised would most specifically indicate hepatocyte damage?
alanine transaminase (ALT)
epigastric pain following meals. diagnosed with gallstone disease. what blood test when raised would reliably indicate that a gallstone is stuck in the common bile duct?
conjugated bilirubin levels
25y/o presents with 3 month history of bloody diarrhoea. diagnosed with IBD. which of the following characteristics would make a diagnosis of UC more likely than crohn’s disease?
- presence of disease in rectum
which transporter moves glucose across the basolateral membrane of the enterocyte?
GLUT-2
what does the term ‘mass movement’ describe
rapid movement of colonic content
- triggered by gastrocolic reflex
2 week history of epigastric pain- GP suspects acute gastritis. the visceral afferent nerve responsible for relaying this pain follows which autonomic nerve back to the spine?
greater splanchnic
- stomach is a foregut structure
indirect inguinal hernia
through which anatomical site does this hernia leave the abdomen?
deep inguinal ring
which pancreatic protease enzyme, once activated, is itself a catalyst for activation of other pro-enzymes?
trypsin
what is the name given to the structure that facilitates the movement of digested fats through the aq medium of the gut lumen toward the enterocyte?
micelle
what provides the liver with its greatest structural support with the abdo cavity?
IVC
the anterolateral abdo muscles are arranged in layers. which is the sequence from superficial to deep?
external oblique, internal oblique, transversus abdominis
what are the borders of Hesselbach’s triangle?
inguinal ligament, inferior epigastric vessels, lateral border of the rectus abdominus muscle
the anterior boundary of the lesser sac is partially formed by the?
posterior surface of the stomach
the greater sac is divided into the supra colic and infracolic compartments. what structure forms the physical divide between these compartments?
transverse mesocolon
the paracolic gutters are channels within the peritoneal cavity that connect the supra colic and infracolic compartments. where do they lie?
lateral to the ascending and descending colon
below the arcuate line (between the umbilicus and the pubic ones in a horizontal plane) the post surface of the rectus abdominus muscles are in contact with which structure
transversalis fascia
- above the arcuate line, the aponeurosis of internal oblique divides and envelops the rectus muscle.
- above the arcuate line, the rectus sheath has a posterior element to it
- below the line there is no posterior element and the rectus muscle lies directly on transversalis fascia
at what spinal level does the oesophagus pierce the diaphragm
T10
what structure lies around the oesophageal hiatus (where the oesophagus pierces the diaphragm) and helps prevent the reflux of stomach content into the oesophagus?
right crus of diaphragm
what branch of the coeliac artery gives rise to the L gastroepiploic artery
splenic artery
the hepatic portal vein usually originates behind which part of the pancreas?
neck
what type of hernia might be precipitated by a weakened conjoint tendon
direct inguinal hernia
- conjoint tendon serves to reinforce the medial part of the pot wall of the inguinal canal
- lies behind the superficial inguinal ring
what is the main reason a strangulated abdo hernia requires urgent medical attention
blood supply to hernia is compromised
which structure lies in the free edge if the lesser omentum?
hepatic artery
- with hepatic portal vein and common bile duct
what are the differences between the greater and lesser omentums?
greater omentum:
- 4 layers of visceral peritoneum
- from greater curvature of the stomach and proximal part of the duodenum folds back up and attaches to ant surface of transverse colon
lesser omentum:
- 2 layers of visceral peritoneum,
- lesser curvature of the stomach and prox part of duodenum to liver
what are the nerve roots for the sympathetic outflow?
T5-L2
what are the nerve roots for the splanchnic nerves?
greater: T5-T9 foregut
lesser: T10-T11 midgut
least: T12 hindgut
where is pain felt in a caecal volvulus ?
- distended small bowel
- visceral afferents activated to least splanchnic nerve
- converge with somatic afferents at spinal cord level T10-11
- brain interprets as T9 and T10 dermatomes
- peri-umbilical pain
