Spinal cord and Reflex actions

Spinal cord:

It is the long cylindrical part of CNS. It is present in the neural canal of the vertebral column. It is the center of all reflex actions. Grey matter, which has a pinkish-grey color in the living brain, contains the cell bodies, dendrites and axon terminals of neurons, so it is where all synapses are. White matter is made of axons connecting different parts of grey matter to each other. In spinal cord grey matter is inside and white matter is outside. Major functions of spinal cord are:

1. It acts as the main center for reflex actions.
2. It acts as a link between spinal nerves and brain. Thus it participates in conscious actions.

Reflex actions:

It is defined as an involuntary action performed by muscles under the direction of the spinal cord in response to the stimulus. The best example of the reflex action is pulling of hand when we touch hot or very cold objects and contraction of the pupil when the light is shown in the eye.

Reflex arc:

The path which is followed by impulses during the reflex action is called the reflex arc. It consists of an afferent (or sensory) nerve, usually one or more interneurons within the central nervous system, and an efferent (motor, secretory, or secretomotor) nerve.