Which of the following is the immediate covering of a nerve fibre?

Some cells of our body can be over a foot long. These are

Four healthy people in their twenties were involved in injuries resulting in damage and death of a few cells of the following types. Which of these cells are least likely to be replaced by new cells?

Which one of the following is not essentially a part of the nervous system?

In a neuron,the components known as Nissl's granules are now identified as:

The axon of a neuron ends in .......