(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. |