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Biological Psychology
Key Point for this Unit:
Everything psychological is
simultaneously biological!!
Dendrites – receive messages from other cells
and conduct impulses toward the cell body
DendritesNEURON
Cell Body – the cell’s life-support center
Dendrites
Cell Body
NEURON
Axon – the extension of a neuron through which messages
are sent to other neurons or to muscles or glands
Dendrites
Cell Body
Axon
NEURON
Myelin Sheath – a layer of fatty cells covering
the axon, helps speed neural impulses
Dendrites
Cell Body
Axon
Myelin Sheath
NEURON
Terminal branches of axon – form junctions
with other cells
Dendrites
Cell Body
Axon
Myelin Sheath
Terminal branches of axonNEURON
Biological Psychology
It is all about the body!!!!Concerned with the links between biology and
behavior (also called Neuroscience)
The Nervous System
It starts with a NEURON: an individual nerve cell; the basic building block of the nervous system
How does a Neuron fire?• Resting Potential: slightly
negative charge.
• Reach the threshold when enough neurotransmitters reach dendrites.
• Threshold: level of stimulation required to trigger a neural impulse; excitatory signals minus inhibitory signals must equal a minimum intensity
• Go into Action Potential; a neural impulse (brief electrical charge) that travels down an axon.
• All-or-none response.
TYPES OF NEUROTRANSMITTERS
Chemical messengers that that traverse the synaptic
gap between neurons
REVIEW… remember
agonists and antagonists???
Agonist – mimic neurotransmitters
**Example: Morphine mimics endorphins
Antagonist – block neurotransmitters
**Example: Poison blocks muscle
movement
Did you know? Botox is an antagonist that paralyzes facial muscles!
Acetylcholine (ACH)
• Involved with voluntary muscle movement, learning and memory
• Lack of ACH has been linked to Alzheimer’s disease.
Dopamine
• Deals with motor movement and alertness.
• Lack of dopamine has been linked to Parkinson’s disease.
• Too much has been linked to schizophrenia.
Serotonin
• Involved in mood control.
• Lack of serotonin has been linked to clinical depression.
Endorphins
• Involved in pain control.
• Many of our most addictive drugs deal with endorphins.
“Runner’s High”
occurs when your
brain signals the
release of
endorphins to
reduce pain!
Did you know? The word
“endorphin” literally means
“morphine within”!
The Nervous System
The Nervous System - body’s speedy,
electrochemical communication network consisting
of nerve cells
Central Nervous System (CNS)
•The Brain and spinal cord
• Neural networks –
interconnected neural
cells; more
connections made as
experience gained
Peripheral Nervous System (PNS)
• All nerves that are not encased in bone.
• Sensory and motor
neurons that connect
the CNS to the rest of
the body
• Is divided into two categories….somaticand autonomic.
Somatic Nervous System
• Controls voluntary muscle movement.
• Uses motor neurons.
Autonomic Nervous System• Controls the
automatic functions of the body.
• Divided into two categories…the sympathetic and the parasympathetic
Sympathetic Nervous System
• Arouses the body
• Fight or Flight Response.
• Automatically accelerates heart rate and breathing, dilates pupils
Parasympathetic Nervous System
• Calms the body
• Automatically slows the body down after a stressful event.
• Heart rate and breathing slow down, pupils constrict
Sympathetic and
Parasympathetic
Types of Neurons
• Sensory Neurons –sends receptors to CNS
• Interneurons – internal communication neurons
• Motor Neurons – CNS to muscle and glands
Reflexes• Normally, sensory
neurons take info up through spine to the brain.
• With reflexes though, some reactions occur when sensory neurons reach just the spinal cord.
• Automatic response to sensory stimulus; interneurons react to sensory neurons w/o going to brain
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