Sem 1 - GIT and Liver

Question 1

What type of epithelium lines the oesophagus? This type of epithelium is best adapted for?

Answer 1

stratified non-keratinising squamous. withstanding abrassion

Question 2

What type of gland is in the submucosa of the oesophagus?

Answer 2

seromucinous (containing both serous and mucous cells).

Question 3

Does the oesophagus have an adventitia or serosa, why?

Answer 3

The oesophagus is in the mediastinum rather than a cavity and is mostly surrounded by adventitia.

Question 4

intercellular bridges and keratin pearls are features of what?

Answer 4

squamous differentiation

Question 5

the presence of keratin in the extracellular matrix will likely cause what? why?

Answer 5

a granulomatous response to foreign material.

the body sees keratin as foreign material so neutrophils, macrophages and multinucleate giant cells respond.

Question 6

compare the glands in different parts of stomach

Answer 6

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.

Question 7

definition of erosion and ulcer

Answer 7

erosions involve the muscosa only, whereas ulcers extend into submucosa or deeper.

Question 8

usual location of chronic benign gastric ulcers?

Answer 8

Antrum (on the lesser curve)

Question 9

Which region of the stomach would a gastroenterologist biopsy for histopathological diagnosis in a patient with suspected Helicobacter gastritis?

Answer 9

Antrum or pylorus

Question 10

Which region of the stomach would a gastroenterologist biopsy if a histopathological diagnosis was required in a patient with suspected pernicious anaemia?

Answer 10

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.

Question 11

where and in what layer are brunner’s glands.

Answer 11

submucosal duodenum

Question 12

what causes elongated crypts or glands at a cellular level?

Answer 12

epithelial stem cell hyperplasia

Question 13

What region of the GIT do the epithelium and glands resemble of the appendix resemble?

Answer 13

Large intestine

Question 14

explain the inflammatory course and pain history in appendicitis. why is this? what causes the pain

Answer 14

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.

Question 15

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)?

Answer 15

ruptured or perforated, leading to acute bacterial peritonitis and septic shock.

Question 16

Which of the following macroscopic features is the appendix likely to have demonstrated? (3)

Answer 16

swelling, redness and a fibrinous serosal exudate

Question 17

Hepatocytes often normally have a finely vacuolated cytoplasm. What predominantly contributes to this appearance?

Answer 17

glycogen

Question 18

Do all hepatocytes of the different histological units have the same function biochemically? Explain

Answer 18

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.

Question 19

what are zone 1 hepatocytes specialzed is from a biochemical standpoint

Answer 19

gluconeogenesis and cholesterol synthesis

Question 20

which liver zone is important for cytochrome P-450-based functions

Answer 20

3

Question 21

If the right ventricle started to fail, in which sinusoids would vasocongestion be seen initially, those around central veins or portal tracts? why?

Answer 21

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).

Question 22

what is brown pigment in hepatocytes most likely to be (2)?

Answer 22

lipofuscin, stored iron