Biological Bases of Behavior

Mrs. HensleyAP Psych 2014

Why are psychologists concerned with human biology?

• Everything psychological is simultaneously biological”– We think, feel, and act with our bodies.

1800s: Franz Gall invented phrenology (a popular theory that claimed that bumps on the skull reveal our mental abilities and our character traits.

-Although bumps on our skull reveal nothing about the brain’s underlying functions, Gall was accurate in supposing that various brain regions have particular functions.

-We are composed of subsystems, tiny cells organize to form body organs, and these systems are even part of a larger system-THE INDIVIDUAL, who in turn is part of a family, culture, and community.

-We are BIOPSYCHOSOCIAL systems!

Neural and Hormonal Systems

Will Explain Why We FEEL……

Pain

Strong

Sick

Nervous

It all Starts with the Neuron

Describe the parts of a neuron.• Neuron: consists of a cell body and branching fibers• Dendrite: receive information from sensory receptors (or other

neurons)• Axon: send information to other neurons• Sensory Neurons: send information to body’s tissues and sensory

organs inward to the brain and spinal cord (which processes information)

• Motor Neurons: carry outgoing information from the central nervous system to the body’s tissues.

• Interneurons: communicate internally and intervene b/n the sensory inputs and the motor outputs

• Myelin sheath: helps speed impulses

Neuron Structure

Neurons do NOT touch each other- the space in between is call the synapse.

How Neurons Communicate