Question

Choose the correct answer from the alternatives given.
Which of the following are the first and last elements in a spinal reflex?

• A. Axon and dendrite
• B. Sense organ and muscle effector
• C. Ventral horn and dorsal horn
• D. Motor neuron and sensory neuron

Answer 1

The correct option is B Sense organ and muscle effector

• Receptor - sense organ in the skin, muscle, or another organ.
• Sensory neuron - carrier impulse within CNS

Interneuron - carrier impulse within CNS

• Motor neuron - carrier impulse towards CNS
• Effector - structure by which an animal responds.

So, the correct option is 'Sense organs and muscle effector'.