The Biology of Behavior: Is the Brain the Organ of Mental Life?

Introduction

The principal functional units of the brain and the nervous system are neurons. The neuron is a living cell with a cell wall and a nucleus. Unlike other cells of the body, neurons specialize in transmitting messages. Of particular importance are two structures called the dendrite and the axon. A neuron often has more than one dendrite; dendrites are reminiscent of a root system.

They act like antennas, picking up information and sending it in the direction of the cell body. The axon extends from the cell body like a long filament. Although there can be more than one dendrite, there is always just one axon. The axon consistently sends information away from the cell body, often to an adjacent neuron.

After completing the chapter, you will be able to

• explain the way in which a neuron functions;
• describe the structure of the nervous system;
• specify some of the principal structures and functions of the brain;
• differentiate between the functions of the left and right hemispheres of the brain;
• identify the endocrine glands and their functions.

In the 1983 Steve Martin film The Man with Two Brains, a woman’s personality is changed when her own brain is removed and then replaced with a different one. The plot is based on the assumption that the brain is the organ of mental life. Buy Weed

This assumption, associated with the biological viewpoint (see chapter 1), sees the activity of the brain and nervous system as the basis of consciousness. The relationship between the brain and the mind in this way of looking at things is roughly the same as the relationship of a piano to the melody that one hears when the piano is played. The piano, like the brain, is a physical organ. The melody, like the mind, is somewhat less tangible.

The Building Block of the Nervous System:

The principal functional units of the brain and the nervous system are neurons. The neuron is a living cell with a cell wall and a nucleus. Unlike other cells of the body, neurons specialize in transmitting messages. Of particular importance are two structures called the dendrite and the axon.

A neuron often has more than one dendrite; dendrites are reminiscent of a root system. They act like antennas, picking up information and sending it in the direction of the cell body. The axon extends from the cell body like a long filament. Although there can be more than one dendrite, there is always just one axon. The axon consistently sends information away from the cell body, often to an adjacent neuron.