Differentiate between: (Any four)
$(a)$ Myelinated and non-myelinated axons
$(b)$ Dendrites and axons
$(c)$ Rods and cones
$(d)$ Thalamus and Hypothalamus
$(e)$ Cerebrum and Cerebellum

The $Facial$ nerve is:

Draw labelled diagrams of the following:
$(a)$ Neuron
$(b)$ Brain
$(c)$ Eye
$(d)$ Ear

Explain the following:
$(a)$ Role of $Na ^{+}$ in the generation of action potential
$(b)$ Mechanism of generation of light-induced impulse in the retina.
$(c)$ Mechanism through which a sound produces a nerve impulse in the inner ear.

Briefly describe the structure of the following:
$(a)$ Brain
$(b)$ Eye
$(c)$ Ear

Where is postganglionic sympathetic cholinergic innervation found?