(Recall: Nerve impulses are transmitted by neurones to and from the central nervous system)
Brain:
- Contained within the skull which protects it. → From brain → Spinal Chord runs down the back of the body. The Spinal cord passes through the vertebral column (backbone) which protects it.
Spinal nerves:
- connect spinal chord to various parts of the body.
- like all nerves → they are composed of bundles of nerve fibres.
- divided into 2 roots just before joining spinal cord
Spinal nerves → emerge at intervals along the length of the spinal chord.
→ as the spinal nerve leaves the spinal chord → it progressively subdivides into branches → supplying nerve fibres to various parts of the body.
transverse section of spinal chord through the region containing spinal nerves
(familiarise yourself with this picture properly)
From the picture → synapses occur in the central inner part of the spinal chord → which transmits nerve impulses to and from the brain
Note
- Spinal cord → plays important roles → both voluntary actions and reflex actions