(a) Differences between myelinated axon non myelinated axon.
| Myelinated Axons | Non- Myelinated axon |
| Myelin sheath is present around them. | Myelin sheath is absent. |
| Nodes of Ranvier are present at intervals. | Nodes of Ranvier are absent. |
| They appear white in fresh state. | They appear grey in fresh state. |
| Conduction is fast. | Conduction is slow. |
(b) Differences between dendrites and axons.
| Dendrites | Axons |
| These are extensions of the cyton present at the anterior position. | These are the extensions of the cyton present at the posterior position. |
| These are numerous in number. | These are only one in a neuron. |
(c) Differences between rods and cones
| Rod Cells | Cone cells |
| They are about 120 million in human eye. | They are about 7 millions in human eye. |
| Outer segment is cylindrical and contains rhodopsin. | Outer segment is conical and contains iodopsin. |
| Inner end bears a knob. | Inner end is branched. |
| All the rod cells are alike and take no part in colour vision. | Cone cells provide colour vision. |
| These cells are sensitive to low light intensity and function in dim light. | Cone cells are sensitive to high light intensity i.e. function in bright light. |
(d) Differences between thalamus and hypothalamus.
| Thalamus | Hypothalamus |
| The side of the diencephalon is called thalamus. | The floor of the diencephalon is called hypothalamus. |
| It is a major coordinating centre for sensory and motor signalling. | It has centres that control body temperature, eating and drinking. |
| It secretes no hormones. | It secretes hormones. |
(e) Differences between cerebrum and cerebellum.
| Cerebrum | Cerebellum |
| It is part of fore brain. | It is a part of hindbrain. |
| The two sides (cerebral hemisphere) are connected by corpus callosum. | The two sides of cerebellum are joined by pons varolli. |
| Its cavities are called lateral ventricles (paracoel). | It is almost solid and contains only narrow cerebellar ventricle (metacoel). |
| It relays impulses to all parts and control voluntary movements and seat of intelligence and memory. | It is the seat of equilibrium. |