commands came for Ihe constraction of those muscler, of the limb which would cause its Fig I0 4.

commands came for Ihe constraction of those muscler, of the limb which would cause its Fig I0 4. 1 Reflex arc contraction of Ihe muscles Therefore, if now the spinal cord is destroyed, this reflex will disappear and in actual practice, this happens This experiment is rather dramatic, but all reflexes have these two basic characteristics, viz . (i) sensory to motor conversion is through CNS participation, (ii) non participation of volition Numerous such examples may be given Thus while walking bare footed, a person Treads over a thorn -> he withdraws his affected limb while extends his other limb (to support ihe body weight),the whole action is reflex and does not require the presence of will (That the person becomes aware of the pain due to the thorn prick is merely an accompanying phenomenon, not necessary for the reflex actron) THE REFLEX ARC To slart with, reflex arc of a spinal reflex may be considered A painful stimulus is applied to The limb -> flexor muscles of the limb contract withdrawal (flexion) of The limb The reflex arc consists of: (A) the afferent limb, consisting of, (i) receptor, and (n) Ihe afferent (sensory) nerve (B) Ihe efferent limb. consisting of. (i) Ihe moloneuf on and (it) Ihe effector organ. (C) the center This is The part ol Ihe CNS, where Ihe allerenl limb ends and either synapse’ directly with the efferent motaneuron or establishes its connection via an intercalated neuron, wilh Ihe efferent motoneuron The receptor (present in the skin) 'catches'the stimulus, then transmits the impulse to the center via the afferent