spinal reflex Flashcards
Conscious Response
A conscious response to a sensory stimulus is a reaction that involves awareness. You will have paid attention to the stimulus and therefore know about it.
The response will be a voluntary ‘intentional’ reaction.
For example – putting on a jacket when you go outside and notice it is cold.
Unconscious Response
An unconscious response to a sensory stimulus is a reaction that does not involve awareness.
The response will be ‘involuntary’, unintentional, automatic and we cannot ordinarily control its occurrence.
For example – your heart beating automatically.
The Spinal Cord
The spinal cord is made of bundles of nerves fibres and extends from the base of the brain to the lower back. The nerve fibres are described as white matter (axon) and grey matter (dendrites). See diagram A. The spine is encased in the spinal column See diagram B. The spinal column is made up of bones called vertebrae. The spinal cord has 2 main functions:
to pass sensory information from the PNS to the brain.
pass information from the brain to the PNS.
The Spinal Reflex
The spinal cord does more than provide pathways for messages to and from the brain.
It can also initiate some simple responses on its own independently of the brain.
A spinal reflex is an unconscious, involuntary and automatically occurring response to certain stimuli without any involvement of the brain.
Is a survival mechanism used for the body.
It is often referred to as a reflex arc because the response to an incoming stimulus is automatically ‘reflected back’ from the spinal cord without any initial input from the brain and before the brain processes a conscious perception of the stimulus.
