Myers’ PSYCHOLOGY (7th Ed) Chapter 2 Neuroscience, Genetics and Behavior James A. McCubbin, PhD Clemson University Worth Publishers

Fact vs. Falsehood z1. A small amount of brain tissue from a person cannot be distinguished from that of a monkey. z2. The human brain produces its own natural opiates that elevate mood and ease pain. z3. The brain accounts for a larger percentage of body weight in humans than in any other species. z4. Electrically stimulating a cat’s brain at a certain point can cause the animal to cower in terror in the presence of a small mouse. z5. Both animals and humans seem to have reward centers located in the brain. z6. We ordinarily use only 10 percent of our brains. z7. Some people can write but are unable to read. z8. If a blind person used one finger to read Braille, the brain area dedicated to that finger expands. z9. Adult humans cannot generate new brain cells. z10. Some people have had the hemispheres of their brains split with no apparent ill effect.

Vocabulary Terms  Biological Psychology  Neuron

Neural Communication  Biological Psychology  branch of psychology concerned with the links between biology and behavior  Other titles: behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists  Neuron  a nerve cell  the basic building block of the nervous system

Types of Neurons: Vocab zSensory zMotor zInterneuron

Type of Neurons zSensory (also called afferent): carry messages from sense organs to the spinal cord or brain zMotor (also called efferent): carry messages from the spinal cord or brain to the muscles and/or glands zInterneuron (also called association): carry messages from one neuron to another

Neural Communication  Dendrite  the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body  Axon  the extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands  Myelin [MY-uh-lin] Sheath  a layer of fatty cells insulating the fibers of many neurons  enables vastly greater transmission speed of neutral impulses

Neural Communication

Speed of Neurons zAll neurons either work or the don’t. They are all or nothing. The difference is in the speed. They vary from 2 – 200 mph

Vocabulary zAction potential zResting potential zSelectively permeable zExcitatory zInhibitory zThreshold

Vocabulary zAction potential: 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 zResting Potential: time it has to wait before sending another message zSelectively permeable: only some messages make it in (regulates the resting potential) zExcitatory: messages that so “Go”! zInhibitory: messages that say “Do nothing” zThreshold: how much it takes to deliver the message

Neural Communication Cell body end of axon Direction of neural impulse: toward axon terminals

Vocabulary zSynapse: the junction (space is called gap) in between neurons zNeurotransmitters: jump the gap to deliver messages

Neural Communication

Serotonin Pathways Dopamine Pathways

Neural Communication

Neural Communication: Vocabulary  Acetylcholine [ah-seat-el-KO-leen]  a neurotransmitter that, among its functions, triggers muscle contraction  Endorphins [en-DOR-fins]  “morphine within”  natural, opiate like neurotransmitters  linked to pain control and to pleasure

Neural Communication Neurotransmitter molecule Receiving cell membrane Receptor site on receiving neuron Agonist mimics neurotransmitter Antagonist blocks neurotransmitter

vocabulary  Nervous System  Central Nervous System (CNS)  Peripheral Nervous System (PNS)  Somatic Nervous System  Autonomic Nervous System  Sympathetic Nervous System  Parasympathetic Nervous System

The Nervous System  Nervous System  the body’s speedy, electrochemical communication system  consists of all the nerve cells of the peripheral and central nervous systems  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 Central (brain and spinal cord) Nervous system Autonomic (controls self-regulated action of internal organs and glands) Somatic or Skeletal (controls voluntary movements of skeletal muscles) Sympathetic (arousing) Parasympathetic (calming) Peripheral

The Nervous System  Nerves  neural “cables” containing many axons  part of the peripheral nervous system  connect the central nervous system with muscles, glands, and sense organs

The Nervous System

vocabulary zReflex

The Nervous System  Reflex  a simple, automatic, inborn response to a sensory stimulus Skin receptors Muscle Sensory neuron (incoming information) Motor neuron (outgoing information) Brain Interneuron Spinal cord

The Nervous System  Neural Networks  interconnected neural cells  with experience, networks can learn, as feedback strengthens or inhibits connections that produce certain results  computer simulations of neural networks show analogous learning InputsOutputs Neurons in the brain connect with one another to form networks The brain learns by modifying certain connections in response to feedback