Question

Distinguish between the following pairs: 

(i) Afferent neurons and Efferent neurons. 

(ii) Mixed and motor nerves 

(iii) Dorsal and ventral spinal roots.

Answer 1

(i) Afferent neurons and Efferent neurons:

S. No	Afferent neuron	Efferent neuron
(i)	They conduct impulses from the receptors to the CNS	They conduct impulses from CNS to the effectors.
(ii)	They are sensory in nature.	They are motor in nature.

(ii) Mixed and motor nerves:

S. No	Mixed	Motor nerve
(i)	It has both motor and sensory neurons.	It has only motor neurons.
(ii)	Sensory carry impulses to CNS from receptors and simultaneously motor fibres conduct impulses from CNS to muscles and glands.	It conducts nerve impulses from CNS to some muscle or gland to control their activities.
(iii)	Arise from spinal cord.	Arise from spinal cord brain (CNS).

(iii) Dorsal and ventral spinal roots:

S. No	Dorsal spinal roots	Ventral spinal roots
(i)	They are made of sensory (afferent) nerves.	They are made of motor (efferent) nerves.
(ii)	Their cell bodies are located in dorsal root ganglia.	The cell bodies of ventral spinal root is located in ventrolateral horn or grey mater.