Flashcards in LMN reflexes Deck (11):
In motor neurons what is the function of the brain & spinal cord?
-Brain= Initiation, Integration, Co-ordination
-SC=Simple reflexes, pattern generation
What is the proposed function, sensory afferent & sensory stimuli of myotatic reflex?
-Change in muscle length
What is the proposed function, sensory afferent & sensory stimuli of an inverse myotatic reflex?
-Change in muscle tension
What is the proposed function, sensory afferent & sensory stimuli of a flexor withdrawal reflex?
-Damage limitation of avoidance
-Maintained balance on limb withdrawal
-A-delta, C, group III/IV
-Painful or damaging stimuli
What is the definition of a reflex?
A fast, predictable automatic response to a change in the environment or a stimulus
What are the types of integration that can occur?
-Monosynaptic=1 synapse, rapid
-Polysynaptic=2 or more synapses, slower more complex
What does addition of a load to the arm lead to?
-Stretch of flexor biceps brachii & activation of the 1a afferent
-Direct excitation of agonist (flexor) muscle group-biceps
-Indirect inhibition via 1a inhibitory interneuron of agonist muscle group (extensor)-triceps
What does the golgi tendon provide
Tension feedback mechanism
What does an increased muscle tension lead to in a golgi tendon organ?
-Golgi Tendon Organ excitation
-Inc firing in Ib afferent
-Indirect inhibition via an inhibitory interneuron (disynaptic link) of the motor neuron
-Relaxation/inhibition of the homonymous muscle
If you stand on a pin with your right foot, what needs to happen to lift your foot up? What type of reflex is this?
-Crossed extensor/flexor withdrawal reflex
-Inc activity in A-delta &c afferents
-Ipsilateral polysynaptic excitation of flexors & polysynaptic inhibition of extensors
-Contralateral polysynaptic inhibition of flexors & excitation of extensors
-Ensures that when leg is lifted you don't fall over-maintains balance