Distinguish between impulse conduction in a myelinated nerve fibre and unmyelinated nerve fibre.
|
Impulse conduction in a myelinated nerve fibre |
Impulse conduction in non myelinated nerve fibre |
|
1. Conduction of nerve impulse is faster by twnety times. 2. It uses less energy because only nodesare depolarized. 3. It uses less energy because only nodes are depolarizsed. 4. Ion exchange occurs at nodes only. |
1. It is slow. 2. It is smooth. 3. It uses more energy because whole of fibreis depolarized. 4. Ion exchange occurs through out. |
Distinguish between
(d) blind spot and yellow spot.
Blind spot :
1. No image is formed.
2. No specific name forits centre.
3. It has no rods arises from it.
4. Optics nerve arises from it.
5. Eye coats absent.
6. It does not lie on principal axis.
Yellow Spot :
1. It is point where image is formed on retina.
2. Its centre is called fovea centralis.
3. It has only cones.
4. Optic, nerve does arise from it.
5. Present
6. It is present on principal axis.
What is cochlear microphonics?
Cochlear microphonic is the electrical potential generated in the hair cells of the organ of Corti in response to acoustic stimulation.
Distinguish between
(e) cranial nerves and spinal nerves.
|
Cranial Nerves |
Spinal Nerves |
|
1. They arise from brain. 2. They may be sensory, motor or mixed. 3. They are 12 pairs. 4. They may be unbranched or branched. 5. These are not formed by dorsal and ventral roots. 6. They come out formina of skull. |
1. They arise from spinal cord except 1st pair which develops from medulla oblongata. 2. They are mixed. 3. They are 31 pairs. 4. They are branched, each gives 3 branches. 5. They are formed by dorsal and ventral roots. 6. They emere out between intervertebral foramina. |
Distinguish between aqueous humor and vitreous humor.
Aqueous humour :
1. Is is found in anterior chamber of eye.
2. It is watery fluid.
3. It is secreted by ciliary processors.
4. It is absorbed by blood.
5. It contains most of diffusible substances of the plasma.
6. Its obstruction may damage retina if it does not flow and causes glaucoma.
Vitreous humour :
1. It is present in posterior chamber of eye.
2. It is jelly like material.
3. It is secreted by retian during development of eye.
4. It is never absorbed or never replaced.
5. It contain 90% of water, vitrein protein, mucopoly saccharide called Hyaluronic acid.
6. It does not cause glaucoma.
Switch
