Biology
The diagram given below shows the internal structure of a spinal cord depicting a phenomenon. Study the diagram and answer the questions:
(i) Name the phenomenon that is depicted in the diagram. Define the phenomenon.
(ii) Give the technical term for the point of contact between the two nerve cells.
(iii) Name the parts numbered 1, 2 and 3.
(iv) How does the arrangement of neurons in the spinal cord differ from that of the brain?
(v) Mention two ways by which the spinal cord is protected in our body.
Nervous System
ICSE 2018
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Answer
(i) The phenomenon that is depicted here is the reflex action which is involuntary action and instant movement in response to stimuli.
(ii) Synapse
(iii) The parts numbered 1, 2 and 3 are:
- 1 → Sensory nerve
- 2 → Motor nerve
- 3 → Grey matter/Central canal
(iv) In the brain, Gray matter is present on the outside and white matter on the inner side. In Spinal cord, white matter is present on the outside and Gray matter on the inner side.
(v) Two ways by which the spinal cord is protected in our body are:
- The spinal cord is protected by 26 bones called vertebral columns.
- CSF or cerebrospinal fluid also protects the spinal cord.
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