Chapter 2 Biopsychology

How Does the Body Communicate Internally? The body’s two communication systems, the nervous system and the endocrine system, both use chemical messengers to communicate with targets throughout the body

The Neuron Types of Neurons Sensory neurons (carry messages from sense receptors towards the CNS) Motor neurons (carry messages from CNS toward muscles and glands) Interneurons (carry messages between nerve cells)

The Structure of a Neuron

The Neural Impulse Neural impulse – Brief electric surge that carries the neuron’s message Ions – Charged particles that are moved across the cell membrane

The Neural Impulse Resting potential Action potential Synapse Synaptic transmission

Neurotransmitters Neurotransmitters – Chemical messengers that relay neural messages across the synapse

Seven Important Neurotransmitters Dopamine Serotonin Norepinephrine Acetylcholine GABA Glutamine Endorphins

Schizophrenia, Parkinson’s disease Neurotransmitters Normal Function: Produces sensations of pleasure and reward; used by CNS neurons in voluntary movement Dopamine Serotonin Norepinephrine Problems with Imbalance: Schizophrenia, Parkinson’s disease Acetylcholine GABA Substances that Affect: Cocaine, amphetamines, Ritalin, alcohol Glutamine Endorphins

Depression, certain anxiety disorders, obsessive-compulsive disorder Neurotransmitters Normal Function: Regulates sleep and dreaming, mood, pain, aggression, appetite and sexual behavior Dopamine Serotonin Norepinephrine Problems with Imbalance: Depression, certain anxiety disorders, obsessive-compulsive disorder Acetylcholine GABA Glutamine Substances that Affect: Prozac, hallucinogenics (e.g. LSD) Endorphins

High blood pressure, depression Neurotransmitters Normal Function: Controls heart rate, sleep, sexual responsiveness, stress, vigilance and appetite Dopamine Serotonin Norepinephrine Problems with Imbalance: High blood pressure, depression Acetylcholine GABA Substances that Affect: Tricyclic antidepressants, beta blockers Glutamine Endorphins

Certain muscular disorders, Alzheimer’s disease Neurotransmitters Normal Function: Primary transmitter used by neurons carrying messages from CNS; involved in some kinds of learning and memory Dopamine Serotonin Norepinephrine Problems with Imbalance: Certain muscular disorders, Alzheimer’s disease Acetylcholine GABA Substances that Affect: Nicotine, botulism toxin, curare, atropine Glutamine Endorphins

Most prevalent inhibitory neurotransmitter in neurons of CNS Neurotransmitters Normal Function: Most prevalent inhibitory neurotransmitter in neurons of CNS Dopamine Serotonin Norepinephrine Problems with Imbalance: Anxiety, epilepsy Acetylcholine GABA Substances that Affect: Barbiturates, tranquilizers (e.g. Valium, Librium), alcohol Glutamine Endorphins

Brain damage after stroke Neurotransmitters Dopamine Normal Function: Primary excitatory neurotransmitter in CNS; involved in learning and memory Serotonin Norepinephrine Acetylcholine Problems with Imbalance: Brain damage after stroke GABA Substances that Affect: PCP (“angel dust”) Glutamine Endorphins

Pleasurable sensations and control of pain Neurotransmitters Dopamine Normal Function: Pleasurable sensations and control of pain Serotonin Norepinephrine Problems with Imbalance: Lowered levels resulting from opiate addiction Acetylcholine GABA Substances that Affect: Opiates: opium, heroin, morphine, methadone Glutamine Endorphins

Plasticity Plasticity – Ability of the nervous system to adapt or change as the result of experience; sometimes helps the nervous system adapt to physical damage

Glial Cells Glial cells Provide structural support for neurons Help in forming new synapses Form myelin sheath

The Organization of the Nervous System Peripheral nervous system Central nervous system (CNS) Autonomic nervous system Somatic nervous system Sympathetic nervous system Parasympathetic nervous system

The Endocrine System (the body’s chemical messenger system)

The Endocrine System Pituitary gland – Master gland that produces hormones influencing the secretions of all other endocrine glands; produces hormone that influences growth; attached to hypothalamus

Copyright © Allyn and Bacon 2006 End of Chapter 2 Section 2.2 Copyright © Allyn and Bacon 2006