Myelin sheath is produced by:

1. Astrocytes and Schwann cells

2. Oligodendrocytes and Osteoclasts

3. Osteoclasts and Astrocytes

4. Schwann cells and Oligodendrocytes

Receptor sites for neurotransmitters are present on:

1. Pre-synaptic membrane

2. Tips of axons

3. Post-synaptic membrane

4. Membrane of synaptic vesicles

Which of the following statement is correct for the node of Ranvier of nerve:

1. Neurilemma is discontinuous

2. Myelin sheath is discontinuous

3. Both neurilemma & Myelin sheath are discontinuous

4. Covered by myelin sheath