Download Neuroscience and Behavior

The Biology of Mind
Chapter 2
Biology and Behavior
• Everything psychological is simultaneously
biological
• Biological psychologists study the links
between our biology and our behavior.
The Biology of Mind
Biology and Behavior
Neural Communication
 A Neuron’s Structure
 How Neurons Communicate
 How Neurotransmitters Influence Us
The Biology of Mind
The Nervous System
 The Peripheral Nervous System
 The Central Nervous System
The Endocrine System
A Neuron’s Structure
Neural Communication
• Neural messages are carried by nerve impulses
called action potentials
– Speeds vary between 2 mph and 200+ mph
– A computer is 3 million times faster
– Still, the brain is vastly more complex than a
computer
• Communication takes place at the synapse, the
junction between the axon of the sending neuron
and the dendrite or cell of the receiving neuron
How Neurons Communicate
• Each neuron is a decision-making device,
deciding whether to fire an action potential or not
(the All-or-none response).
• Each neuron receives signals from hundreds of
other neurons
How Neurons Communicate
• When the action potential reaches the
axon’s end, it releases neurotransmitter
molecules into the synapse
– Chemicals that pass through synaptic gap
• Reuptake: the sending neuron absorbs
excess neurotransmitters left in the
synapse
How Neuron’s Communicate
Types of Neurons
• Sensory neurons carry messages from
the body’s tissues and sensory receptors
to the CNS for processing
• Motor neurons carry instructions from the
CNS out to the body’s tissues
• Interneurons process information
between the sensory input and motor
output
How Neurotransmitters Influence Us
• Opiate drugs (e.g., opium, morphine,
heroin) depress neural activity, temporarily
lessening pain and anxiety
– These drugs act on receptors in the brain that
seem made for opiates
• The brain has its own opiates –
endorphins – which it uses to control pain
and activate feelings of pleasure (“runner’s
high”)
From sensation to muscle