Spinal Reflexes

basic reflex

reflexes we are born with that are usually protective. also called spinal reflexes

acquired reflexes

become reflexive after much practice and learning; not inherent like basic

list 5 components of the reflex arc

• receptor

• efferent pathway

• integrating centre

• afferent pathway

• effector

receptor

detects stimulus

afferent pathway

triggers action potential in afferent neuron

integrating centre

processes and decides efferent information; this is usually the spinal cord in basic reflexes

efferent pathway

transmits the integrating centre’s “decision”/ motor response

effector

receives signals from efferent pathway, typically a muscle

myotatic (stretch) reflex

muscle contraction triggered by passive stretching

muscle spindle

receptor in a stretch reflex, found deep within the muscle belly

monosynaptic reflec

when two neurons, therefore one synapse, are involved

example of monosynaptic reflex

patellar tendon reflex

function of reciprocal innervation

prevents antagonist muscle in the stretch reflex from contracting

pathway of reciprocal innervation

sensory afferent neuron —> inhibitory interneuron —> antagonistic muscle

polysynaptic reflex

involves more than 1 synapse between afferent and efferent neurons