Reflexes Flashcards
Reflexes
Simple motor response to a specific type of stimulus
Afferent pathway
connects receptor to comparator
Efferent pathway
Connects comparator to target
Reflex arc
route followed by nerve impulses in the production of a reflex
involves PNS & CNS
White matter
Bundles of myelinated axons
Grey matter
Cell bodies, accessory cells, unmyelinated axons
Dorsal root
Sensory afferent to enter the spinal chord
Ventral root
Motor efferents / neurones to leave the spinal cord
Sensory neurones
enter spinal chord (afferent)
Motor neurones
leave spinal chord (efferent)
Reflex arc
How it works
1) arrival of stimulus and activation of receptor
2) stimulation of afferent sensory neurone
3) Info processing in CNS
4) Stimulation of efferent neurone
5) Response by effector (target organ / tissue)
Muscle spindles
Act as muscle length detector
Set dynamic range of muscle fibre length
If activated will contract muscle spindle
Golgi tendon organ
Located in junction between muscle fibres and tendon
Motor neurone pools
set of motor neurones that innervate a particular skeletal muscle
Tetanus
An increase of motor neurone action potential frequency
