Read the given statements and select the correct option.
(i) Synaptic cleft of neurons secretes adrenaline.
(ii) Myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon.
(iii) Non-myelinated nerve fibre is enclosed by a Schwann cells that does not form a myelin sheath.
(iii) Spinal and cranial nerves are made of non-myelinated nerve fibres

Q. Consider the following statements and state true or false.
1. Synaptic cleft of neurons secrete adrenaline.
2. Myelinated nerve fibres and enveloped with Schwann cells, which form a myelin sheath around the axon.
3. Non-myelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath.
4. Spinal cord and cranial nerves are made up of non-myelinated nerve fibres.

Q. Consider the following statements and find out coorect option:
(a) Three are two types of axons, namely myelinated and non myelinated
(b) Myelinated nerve fibres found in autonomous and the somatic neural systems
(c) The myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon.
(d) The gap between two adjacent myelin sheaths are calleds nodes of Ranvier.
(e) Unmyelinated nerve fibre found in spinal and cranial nerves
(f) Unmyelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath around the axon.

Q. Read the following statements:
(i) Saltatory type of present in non-myelinated nerve fibres (axons) only
(ii) The nerve impulse generated at a point in the neuron faes resistances at sites where myelin sheath is present
(iii) Nodes of Ranvier of axon is exposed to ECF
(iv) In myelinated neurons, ion channels and transport pumps are absent in the nodes of Ranvier
(v) In myelinated nerve fibre, the nerve impulse travel as a continous wave of depolarisation
How many of the statements are correct?

Q. Assertion:

Q. Read the given statements and select the correct ones.
(i) Autonomic neural system transmits impulses from the CNS to the voluntary organs and striated muscles of the body.
(ii) Unmyelinated nerve fibres do not have Schwann cells which from the myelin sheath.
(iii) Axonal membrane of a neuron while not conducting any impulse is comparatively more permeable to potassium ions (K+) than to sodium ions (Na+).
(iv) A synapse is formed by the membranes of a presynaptic neuron and a post synaptic neuron.