Question

The diagram given below shows the internal structure of a spinal cord depicting a phenomenon. Study the diagram and answer the questions:

1) Name the phenomenon that is depicted in the diagram. Define the phenomenon.

2) Give the technical term for the point of contact between the two nerve cells.

3) Name the parts numbered 1, 2 and 3.

4) How does the arrangement of neurons in the spinal cord differ from that of the brain?

5) Mention two ways by which the spinal cord is protected in our body.

Answer 1

1) Reflex action

Definition - A quick, automatic, involuntary and often unconscious action brought about when the
receptors are stimulated by external or internal stimuli.

2) Synaptic - Junction

3) 

• 1 = Sensory neuron
• 2 = Motor neuron
• 3 = Grey matter with the central canal of the spinal cord

4) The grey matter is present in the cortex (outer side) consisting of cell bodies and white matter is present inside, which consists of myelinated axons in the brain.

In the spinal cord, the grey matter (cell bodies) are present inside, while white matter (Myelinated axon) is present outside.

5) The vertebral column, meninges and cerebrospinal fluid (CSF).