Comparethe following:
(a)Central neural system (CNS) and Peripheral neural system (PNS)
(b)Resting potential and action potential
(c) Choroid and retina
(a)Central neural system (CNS) and Peripheral neural system (PNS)
Central neural system | Peripheral neural system | ||
1. | It is the main coordinating centre of the body. | 1. | It is not the main coordinating centre of the body. |
2. | It includes brain and spinal cord. | 2. | It includes cranial and spinal nerves that connect central nervous system to different parts of the body. |
(b)Resting potential and action potential
Resting potential | Action potential | ||
1. | It is the potential difference across the nerve fibre when there is no conduction of nerve impulse. | 1. | It is the potential difference across nerve fibre when there is conduction of nerve impulse. |
2. | The membrane is more permeable to K+ ions than to Na+ ions. | 2. | The membrane is more permeable to Na+ ions than to K+ ions. |
(c)Choroid and retina
Choroid | Retina | ||
1. | Choroid is the middle vascular layer of eye. | 1. | Retina is the innermost nervous coat of eye. |
2. | It contains numerous blood vessels that provide nutrients and oxygen to retina and other tissues. | 2. | It contains photoreceptor cells, rods and cones that are associated with twilight and colour vision respectively. |