The general term neuroglia is used for a family of non-neuronal cells within the nervous system.
a). Give three named types of neuroglia that may be found within the central nervous system (CNS) and for each type describe one neuroanatomical or structural feature that allows you to distinguish between each. (6 marks)
b). In conventionally stained sections of CNS tissue it is often difficult to distinguish either between these cell types or observe their detailed morphology. Describe one special staining method you could use to fully elaborate each of these cells. In each case give a specific marker or staining method that could be used to distinguish each specific cell type. (8 marks).
c). With regard to the special staining methods you have described in (b), describe two common light microscopy techniques that would be appropriate to view the outcome of the staining. (6 marks).
In the developed world, dementias are a common cause of morbidity in older age groups. Several diseases states may cause dementias. Choose ONE such disease state and provide a detailed account of the histological post-mortem investigation that would be performed to confirm its diagnosis. Your account should incorporate appropriate procedure, appropriate figures and histological/immunohistochemical staining techniques. (20 marks total for this question).
Figure 1 below shows a histological section from a region of the mammalian nervous system. Answer the following questions. (1 mark each).
a) What structure is show?
b) What structure is indicated by the long blue arrow?
c) What region is indicated by A?
d) What region is indicated by B?
e) What structure is indicated by the thin green arrow?
f) What structure is indicated by the orange arrow?
g) What region is indicated by the light blue arrow?
The region marked (c) in figure 1 is shown below at higher resolution.
i) Identify the three large cells
j) With regard to the histological stain that has been used, why is the nucleus of these structures said to be ‘basophilic’
k) The blue arrow indicates a further basophilic substance, what is this and what does the presence of this substance suggest?
Using appropriate hand drawn labeled figures and reference to histological staining techniques, describe how you would microscopically distinguish between the epithelial and connective tissue components present in a hepatic portal tract. (20 marks total for this question) [LO3, LO4]
Question 4 (cont.)
Case study vignette: Barrett’s oesphagus:
A 58 year old man presents to his GP with symptoms of chronic gastric reflux (pain in the upper abdomen/ lower chest towards the heart, acid taste in the mouth, bloating, belching and pain on swallowing hot drinks). He is referred to the hospital for an endoscopic procedure (see figure 1) and several biopsies are taken from the lower oesophagus for histologic examination (see figure 2)
Study and interpret the findings (as shown in figures 1 and 2) to answer the following;
a) What changes to the histological features of the oesophagus might we see due to the effect of the acid reflux? (4 marks)
b) Why is the Alcian Blue/Periodic Acid Schiff technique a good stain choice to histologically demonstrate this feature? (5 marks)
c) What is the name given to this pathologic process? (1 mark) [LO2]
Using appropriate hand drawn, labeled figures and reference to histological tinctorial (dye) staining techniques describe how you would microscopically distinguish between lung and kidney tissue sections stained on the same slide. (20 marks total for this question) [LO3, LO4]
Question 6 (cont.)