Chapter 33, Problem 1RQ

Define the following terms: neuron, axon, dendrite, myelin sheath, afferent neuron, efferent neuron, association neuron.

Summary Introduction

To define: Neuron, axon, dendrite, myelin sheath, afferent neuron, efferent neuron, and association neuron.

Introduction: The nervous system is a complex system, divided into two types – central nervous system and peripheral nervous system. The brain and spinal cord form the central nervous system. The nerves that emerge from the brain and spinal cord form the peripheral nervous system. The neuron is the functional unit of the nervous system.

Explanation of Solution

Neuron: The neuron is a nerve cell that transmits electrical impulses.

Axon: It is a part of a nerve cell, which is a long and thin structure that relays the neuronal signal to the synapse.

Dendrite: It is also called dendron. It is the projection of a nerve cell that receives an impulse from other nerve cells.

Myelin sheath: It is the protective covering of the axon made of myelin protein. The speed of nerve impulse transmission along the axon is enhanced by the myelin sheath.

Afferent neuron: These are the neurons that carry stimuli from the sensory organs to the brain and spinal cord.

Efferent neurons: These are the neurons that carry motor stimuli from the brain and spinal cord to the skeletal muscles.

Association neuron: It is an interneuron that connects the sensory neurons and motor neurons.