Sem 1 - GIT and Liver Flashcards
What type of epithelium lines the oesophagus? This type of epithelium is best adapted for?
stratified non-keratinising squamous. withstanding abrassion
What type of gland is in the submucosa of the oesophagus?
seromucinous (containing both serous and mucous cells).
Does the oesophagus have an adventitia or serosa, why?
The oesophagus is in the mediastinum rather than a cavity and is mostly surrounded by adventitia.
intercellular bridges and keratin pearls are features of what?
squamous differentiation
the presence of keratin in the extracellular matrix will likely cause what? why?
a granulomatous response to foreign material.
the body sees keratin as foreign material so neutrophils, macrophages and multinucleate giant cells respond.
compare the glands in different parts of stomach
In the fundus and body the glands contain many parietal and chief cells.
Whereas the glands of the cardia, antrum and pylorus contain predominantly mucus-secreting cells.
definition of erosion and ulcer
erosions involve the muscosa only, whereas ulcers extend into submucosa or deeper.
usual location of chronic benign gastric ulcers?
Antrum (on the lesser curve)
Which region of the stomach would a gastroenterologist biopsy for histopathological diagnosis in a patient with suspected Helicobacter gastritis?
Antrum or pylorus
Which region of the stomach would a gastroenterologist biopsy if a histopathological diagnosis was required in a patient with suspected pernicious anaemia?
fundus or body. Pernicious anaemia results from destruction of parietal cells by an autoimmune gastritis, with reduced production of intrinsic factor resulting in reduced absorption of vitamin B12.
where and in what layer are brunner’s glands.
submucosal duodenum
what causes elongated crypts or glands at a cellular level?
epithelial stem cell hyperplasia
What region of the GIT do the epithelium and glands resemble of the appendix resemble?
Large intestine
explain the inflammatory course and pain history in appendicitis. why is this? what causes the pain
The inflammation in acute appendicitis starts in the mucosa then spreads transmurally. Until the inflammation involves the serosa, pain is often initially dull and felt in the central abdomen. The appendix touches areas of parietal peritoneum. Inflammation of the visceral serosa or peritoneum of the appendix then spreads to involve adjacent parietal peritoneum where somatic pain fibres are located and the pain becomes more severe and localised. Inflammatory mediators such as bradykinin and prostaglandins cause the pain.
in acute appendicits What is likely to have occurred to the appendix if it had not been removed (i.e why are they taken out urgently)?
ruptured or perforated, leading to acute bacterial peritonitis and septic shock.
Which of the following macroscopic features is the appendix likely to have demonstrated? (3)
swelling, redness and a fibrinous serosal exudate
Hepatocytes often normally have a finely vacuolated cytoplasm. What predominantly contributes to this appearance?
glycogen
Do all hepatocytes of the different histological units have the same function biochemically? Explain
functionally, zone I hepatocytes (of the hepatic acinus) are specialized for different functions from those in zone 3. For example, hepatocytes in zone 1 are specialised for liver functions such as gluconeogenesis and cholesterol synthesis while hepatocytes in zone 3 are more important for cytochrome P-450-based functions.
what are zone 1 hepatocytes specialzed is from a biochemical standpoint
gluconeogenesis and cholesterol synthesis
which liver zone is important for cytochrome P-450-based functions
3
If the right ventricle started to fail, in which sinusoids would vasocongestion be seen initially, those around central veins or portal tracts? why?
Blood from the liver drains via the central veins into hepatic veins then into the IVC. if the right ventricle fails, blood will initially build up in central veins and surrounding sinusoids (rather than those around portal tracts where it enters the liver).
what is brown pigment in hepatocytes most likely to be (2)?
lipofuscin, stored iron
