Reflexes Flashcards
What is a stretch reflex?
It follows a tap to the elastic tendon which transmits to the muscle spindles and causes a negative feedback loop. This uses monosynaptic reflexes with no interneurones which directly activates the alpha motor neurones to the agonist muscle to contract.
What is reciprocal inhibition in a stretch reflex?
It used excitory and inhibitory synapses to make the agonist muscle contract and the antagonist muscle stretches/relaxes.
What is an inverse stretch reflex?
It’s caused be Golgi tendon organs and is a protective muscle to stop tendons being injured under great tension. (Also called clasp knife reflex). The agonist muscle is inhibited and antagonist muscle contracts. This reflex is polysynaptic.
What is the flexor/withdrawal reflex?
Uses information from Nocireceptors to withdraw parts of body away from painful stimuli (flex). They are polysynaptic and protective.
Increased action Potentials from Nocireceptors causes increased activity in the flexor muscles of affected part by excitory neurones and at the same time the extensor antagonist is inhibited.
The sensory neurones branch a lot so all the flexor muscles of affected limb are affected.
What is involved in contralateral extension?
The contralateral limb to the one affected has its extenders excited by excitory interneurones and it’s flexors inhibited by inhibitory interneurones. Sensory information ascends to the brain via the contralateral spinothalmic tract. This all helps to maintain an upright posture.
The same method is used for walking.
What is facilitation?
It increases the sensory input effect so it gives excitation to bring neurones to threshold and can be cause by either similar (pain fibre) or diverse inputs (higher reflexes like biceps).
