unit 3 a biological bases of behavior neural processing and the endocrine system
TRANSCRIPT
Unit Overview• Neural Communication• The Nervous System• The Endocrine System
Click on the any of the above hyperlinks to go to that section in the presentation.
Biological Psychology
branch of psychology concerned with the links between biology and behavior
some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists
Types of Neurons
• Sensory neurons• Carry information from sensory systems to the brain• Also referred to as afferent
• Motor neurons• Carry information from the brain to muscles and glands• Also referred to as efferent
• Interneurons• Carry information between other neurons
Structure of Neurons
• Dendrites• Carry information to the cell body from other neurons
• Cell Body (Soma)• Contains nucleus
• Axon• Carries information to the next cell
• Myelin Sheath• Insulates the axon and speeds up the neural impulse
• Terminal Branches • Found at the end of neurons, connects to the dendrites of next
neuron, contains chemical messengers.
Neurons
•Speed of a neuron impulse• Range from 2 to 200 MPH• Measured in milliseconds
• (thousandths of a second)
Neurons
•Firing of a neuron• Action potential• Ions
• Positively versus negatively charged
•Resting potential•Selectively permeable
Neural Communication Resting Potential
Nothing is happening. The gates are closed and the positive ions are on the outside with the negative ions on the inside of the cell.
• “Negative Ions inside the Neuron is Natural” Action Potential – (Neural Impulse)
a neural impulse; a brief electrical charge that travels down an axon
generated by the movement of positively charged atoms in and out of channels in the axon’s membrane
This process is due to stimulation from either heat, chemicals, pressure or light
Neurons
•Firing of a neuron• Depolarize• Refractory period• Excitatory versus inhibitory• Threshold• All or none response
The Neural Impulse
• Polarization• When the inside of the Neuron is negatively charged relative to the outside
(resting potential)
• Depolarization• When the electrical charge of a cell moves toward zero
Neural Communication
• Refractory Period (Reload, Recharge)• The time it takes for the positive ions to be pumped out.
Threshold the level of stimulation required to trigger a neural impulse
Synapse
Synapse [SIN-aps] a junction between the axon tip of the sending neuron and the dendrite or
cell body of the receiving neuron. This tiny gap is called the synaptic gap or cleft.
Neurotransmitters
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.
Reuptake
Neurotransmitters in the synapse are
reabsorbed into the sending neurons
through the process of reuptake. This
process applies the brakes on
neurotransmitter action.
How Neurotransmitters Influence Us
•Acetylcholine (AcH)•Dopamine•Serotonin•Norepinephrine•GABA•Glutamate•Endorphins
How Neurotransmitters Influence UsHow Drugs and Other Chemicals Alter Neurotransmitters
•Agonists versus antagonists• Agonists (Act)• Antagonists (Block)
Psychopharmacology
• Curare (koo-ra-ray)• Can stun or kill prey quickly• Blocks ACh receptors causing paralysis
• Antipsychotic medications• Block dopamine receptors• Reduces schizophrenic hallucinations
• Caffeine• Increases the release of excitatory neurotransmitters by blocking the
inhibitory neurotransmitter adenosine (a-den-oh-seen)
Psychopharmacology
• How do drugs and alcohol affect our brains?• Mouse party
The Nervous System
• Nervous System: The bodies speedy, electrochemical communication network.
• Central Nervous System (CNS): the brain and spinal cord• Peripheral Nervous System (PNS): the sensory and motor neurons
that connect the body to the CNS
Peripheral Nervous System
• Somatic Nervous System: Controls Voluntary Actions. (I volunteer “Somah” community is a better place. )
• Autonomic Nervous System: Controls our glands and muscles of internal organs.. “My love, you Autonomically make my heart beat”
• Sympathetic Nervous System: arouses and expands energy. When I feel sympathy for someone, my heart beats for them.
• Parasympathetic Nervous System: Conserves energy and calms the body. ”I’m so calm I feel paralyzed.”
The Nervous SystemReflex
a simple, automatic, inborn response to a sensory stimulus
Skinreceptors
Muscle
Sensory neuron(incoming information)
Motor neuron(outgoing information)
Brain
Interneuron
Spinal cord
Endocrine System
• Endocrine System: the body’s “Slow” communication system. • Hormones: Chemical messengers that travel through the body and
brain and affect our behavior. • Adrenal Glands: secrete hormones that arouse the body in times of
stress. • Pituitary Glands: Regulates growth and controls the other endocrine
glands.