Question

Reflex action is

• A. stimulus $\to$ sensory $\to$ motor $\to$ response
• B. stimulus $\to$ motor$\to$ sensory -$\to$ response
• C. reception $\to$ motor $\to$ sensory $\to$ response
• D. sensory $\to$ stimulus $\to$ motor $\to$ response

Answer 1

Answer: (A)

stimulus $\to$ sensory $\to$ motor $\to$ response

Answer 2

Reflex action is a form of animal behaviour in which the stimulation of a sensory organ (receptor) results in the activity of some organ without the intervention of will. If the reflex action is controlled by the spinal cord it is called spinal reflex action and if it is controlled by the brain it is known as cerebral reflex action. For a reflex action five things are normally essential $(i)$ receptor, $(ii)$ sensory nerve fibres, $(iii)$ a part of the central nervous system, $(iv)$ motor nerve fibres and $(v)$ effector organ such as muscles and glands. The sensory nerve fibres bring sensory impulses from the receptor organ to the central nervous system. The motor nerve fibres relay the motor impulses from the central nervous system to the effector organs. Thus an impulse travels a path during reflex action which is called reflex arc.