Week 9 - Microbiology of the GIT Flashcards
What embryological remnant lies within the falciform ligament?
The umbilical vein lies within the ventral mesogastrium during development: develops into ligamentum teres, which is the round ligament of the liver
What conditions could result from stone obstruction of the cystic duct?
- Cholecystitis
2. Biliary colic
What conditions could result from stone obstruction of the common bile duct?
- Cholangitis
2. Jaundice
Outline suitable investigations for dysphagia to solid food.
- Barium swallow
- Oesophago-gastro-duodenoscopy
- Video fluoroscopy
- CXR for external compression
Is the peritoneal cavity an enclosed space?
- In males - enclosed space
2. In females, it is open to the external environment via the infundibulum of the Fallopian tubes
What differences exist in the abdominal wall above and below the arcuate line?
- The rectus muscles are surrounded by the aponeurosis of the other abdominal wall muscles
- Both anterior and posterior to them above the arcuate line
- Only anterior below it
What kind of pain do midgut derivatives produce?
- Intra-peritoneal midgut structures convey a vague periumbilical pain
- When pathology is irritating/distending their visceral peritoneum
What is a Meckel’s diverticulum?
Diverticulum that exists because of the incomplete obliteration of the vitelline duct (omphalomesenteric duct)
With reference to local organs, describe the site of the lesser sac.
Posterior to the liver, lesser omentum and the stomach
It lies immediately anterior to the pancreas
How does the lesser sac form during development in the human?
- The foregut has both a ventral and dorsal attachment to the abdominal cavity
- When the foregut rotates, an enclosed space is created posterior to the stomach - this is called the lesser sac
If you were to insert the tip of your finger into the foramen of Winslow, name 2 tubular structures that would be lying in the peritoneum anterior to your finger.
- Common hepatic artery
- Common bile duct
- Portal vein
Explain why a cancer of the head of the pancreas should cause a patient to be jaundiced.
- A cancer in the head of the pancreas can obstruct the common bile duct as it enters the duodenum
- This will stop bile from following its normal passage into the gut causing a backlog of bile within the biliary system
- As a consequence of this, constituents of bile like bilirubin will be reabsorbed into the blood causing a hyperbilirubinaemia
What is meant by the term obligate anaerobes?
These microorganisms are unable to survive in the presence of oxygen (at least at atmospheric pressure). They survive and thrive in the absence of oxygen.
Which parts of the GIT are predominantly anaerobic zones?
- Parts of the mouth
- Small bowel
- Colon
Describe four beneficial roles that bacteria play in the human GIT.
- Prevent colonisation of pathogens
- Stimulate development of mucosal associated lymphoid tissue
- Stimulate production of natural antibodies
- Kill non-indigenous bacteria
- Assist in the digestion of certain polysaccharides
- Play a role in the synthesis of certain vitamins - Vitamin B12, K