EXPLORING
PSYCHOLOGY
EIGHTH EDITION IN MODULES
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2011
The Biology of Mind
Neural and Hormonal Systems
Module 3
Neural Communication
 Neurons
 How Neurons Communicate
 How Neurotransmitters Influence Us
The Nervous System
 The Peripheral Nervous System
 The Central Nervous System
The Endocrine System
Neural Communication
By studying the links between biological
activity and psychological events, biological
psychologists are gaining a better
understanding of how biology underlies our
behavior and mental processes.
Neuron
A nerve cell, or a neuron, consists of many
different parts.
Neurons
Dendrites: the neuron’s bushy, branching extensions
that receive messages and conduct impulses toward the
cell body.
Axon: the neuron’s extension that passes messages
through its branching terminal fibers that form
junctions with other neurons, muscles, or glands.
Action Potential: a neural impulse; a brief electrical
charge that travels down an axon.
Threshold: the level of stimulation required to trigger a
neural impulse
How Neurons Communicate
Synapse [SIN-aps] the junction between the axon tip
of the sending neuron and the dendrite or cell body
of the receiving neuron. The tiny gap at this junction
is called the synaptic gap or cleft.
Neurotransmitters (chemicals) released from the
sending neuron travel across the synapse and bind to
receptor sites on the receiving neuron, thereby
influencing it to generate an action potential.
Then, in a process called reuptake, the sending neuron
reabsorbs the excess neurotransmitters.
How Neurons Communicate
How Neurotransmitters Influence Us
A particular pathway in the brain may use
only one or two neurotransmitters and
particular neurotransmitters may have
particular effects on behavior and emotions
Serotonin Pathways
Serotonin pathways are
involved with mood
regulation.
From Mapping the Mind, Rita Carter, © 1989
University of California Press
Dopamine Pathways
Dopamine pathways
are involved with
diseases such as
schizophrenia and
Parkinson’s disease.
From Mapping the Mind, Rita Carter, © 1989
University of California Press
Neurotransmitters
How Neurotransmitters Influence Us
Endorphins [en - DOR-fins]: “morphine within”—
natural, opiatelike neurotransmitters linked to
pain control and to pleasure.
Drugs and other chemicals affect brain chemistry
at synapses: Agonist molecules bind to a
neurotransmitter’s receptor and mimics its effects.
Antagonists bind to receptors and block a
neurotransmitter’s functioning.
Nervous System
The Nervous System
Nervous System: Consists of all the nerve cells. It
is the body’s speedy, electrochemical
communication system.
Central Nervous System (CNS): the brain and
spinal cord.
Peripheral Nervous System (PNS): the sensory and
motor neurons that connect the central nervous
system (CNS) to the rest of the body.
The Nervous System
Nerves consist of neural “cables” containing many
axons. They are part of the peripheral nervous
system and connect muscles, glands, and sense
organs to the central nervous system.
Information travels in the nervous system through
three types of neurons. Sensory Neurons carry
incoming information from the sense receptors to
the CNS. Motor Neurons carry outgoing
information from the CNS to muscles and glands.
Interneurons connect these two.
Peripheral Nervous System
Somatic Nervous System: The division of the
peripheral nervous system that controls the body’s
skeletal muscles.
Autonomic Nervous System: Part of the PNS that
controls the glands and other muscles.
Autonomic Nervous System (ANS)
Sympathetic Nervous System: Division of the
ANS that arouses the body, mobilizing its
energy in stressful situations.
Parasympathetic Nervous System: Division of
the ANS that calms the body, conserving its
energy.
Autonomic Nervous System (ANS)
Sympathetic NS
“Arouses”
(fight-or-flight)
Parasympathetic NS
“Calms”
(rest and digest)
Central Nervous System
The brain enables thinking, feeling, and acting
through tens of billions of neurons, all
communicating with thousands of other neurons.
The brain’s neurons cluster into work groups called
neural networks.
The spinal cord connects the peripheral nervous
system with the brain.
Reflexes, simple, automatic responses to
sensory stimuli, illustrate the spinal cord’s work.
A Simple Reflex
The Endocrine System
The Endocrine
System is the body’s
“slow” chemical
communication
system.
Communication is
carried out by
hormones
synthesized by a set
of glands.
Hormones
Hormones are chemical messengers that are
manufactured by the endocrine glands,
travel through the bloodstream, and affect
other tissues..
For example, epinephrine (adrenaline) increases
heart rate, blood pressure, blood sugar, and
feelings of excitement during emergency
situations.
The Endocrine System
adrenal [ah - DREEN-el] glands: pair of endocrine
glands that sit just above the kidneys and secrete
hormones (epinephrine and norepinephrine) that
help arouse the body in times of stress.
pituitary gland: the endocrine system’s most
influential gland. Under the influence of the
hypothalamus, it regulates growth and controls
other endocrine glands.