Cerebellum

Question 1

Draw and label a diagram to illustrate the various histological areas of the cerebellum (8)

Answer 1

The drawing should contain the following labels and detail:
The outer grey matter (the cerebellar cortex) consisting of three layers:
- the molecular layer which contains mainly fibers (1)
- the Purkinje cell layer (1) single cell layer
- very large flask-shaped cell body (1)
- extensively branching dendritic system which extends into the molecular layer (1)
- the granular cell layer (1) overall spotted appearance
- axons of granule cells extend upwards into the molecular layer where they bifurcate to run parallel to the surface to synapse with the dendrites of the Purkinje cells (1)
The inner white matter (medulla) containing the axonal fibre tracts of the Purkinje cells (1)
The deep cerebellar nuclei (1)

Question 2

In a large labelled plan diagram, indicate the histological layers of the cerebellum (3)

Answer 2

Diagram, molecular layer, Purkinje cell layer, granule cell layer, white matter, deep nuclei (½ each)

Question 3

In the diagram above, draw and label the different neuronal structures forming the neuronal circuitry and indicate the flow of information into and out of the cerebellar cortex (7.5)

Answer 3

Afferent (½) mossy fibres (½) synapse onto granule cell (½) dendrites, axons of granule cells form parallel fibres (½) that synapse on Purkinje cell dendrites (½). Afferent (½) climbing fibres (½) synapse directly on Purkinje cells. The axons (½) of Purkinje cells (efferent, ½) connect to the deep nuclei (½) of the cerebellum) (2½for diagram)