1. The Nervous System © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

2. Central vs. Peripheral NS
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

3. Central Nervous System
The CNS is composed of the brain and spinal cord
Spinal cord connects the brain with the PNS
Spinal cord is comprised of cell bodies and axons that carry messages
Afferent: toward the brain (sensory function)
Efferent: away from the brain (motor function)
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

4. Peripheral Nervous System
The Peripheral Nervous System (PNS) includes all nerves outside the brain and spinal cord
Somatic NS carries sensory messages to brain and motor commands to the muscles
Autonomic NS regulates automatic body functions (such as heart rate, breathing)
Sympathetic: “Fight or Flight”
Parasympathetic: dominant when relaxed
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

5. The Autonomic Nervous System
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

6. The Spinal Cord © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

7. Neurons Neurons are cells that transmit information
Neurons are composed of:
Dendrites: receive information and pass it to cell body
Cell Body: summarizes information
Axon: extends from cell body, carries electrical potential, sends a chemical message to adjacent neurons
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

8. Neurons: Structure
© 2011 The McGraw-Hill Companies, Inc.

9. Synapses and Neurotransmitters
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10. Synapse
The synapse is the junction between an axon terminal and an adjacent dendrite or cell body.
Neurotransmitter (NT) molecules are released from the axon terminal into the synapse when the action potential arrives at the axon terminal.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

11. Neurotransmitters Neurotransmitters carry information
across the synaptic gap to next neuron.
Acetylcholine
muscle actions, learning, memory
black widow venom ↑ Ach levels
botox (botulin) ↓ Ach levels
Alzheimer’s disease: ↓ Ach levels
GABA
anxiety: ↓ GABA levels
© 2011 The McGraw-Hill Companies, Inc.

12. Neurotransmitters Glutamate Norepinephrine excitatory
learning & memory
involved in many psychological disorders
Norepinephrine
stress and mania: ↑ norepinephrine levels
depression: ↓ norepinephrine levels
regulates sleep states in conjunction with ACh
© 2011 The McGraw-Hill Companies, Inc.

13. Neurotransmitters Dopamine voluntary movement reward anticipation
stimulant drugs: activate dopamine receptors
Parkinson’s disease: ↓ dopamine levels
schizophrenia: ↑ dopamine levels
© 2011 The McGraw-Hill Companies, Inc.

14. Neurotransmitters Serotonin Endorphins
regulation of sleep, mood, attention, learning
depression: ↓ serotonin levels
prozac: ↑ serotonin levels
Endorphins
natural opiates
mediate feelings of pleasure and pain
© 2011 The McGraw-Hill Companies, Inc.

15. Resting Potential
Sodium ions are concentrated on the outside of the axon membrane.
Potassium ions are concentrated on the inside of the axon membrane.
Ion channels are closed.
The inside of the axon membrane is more negative that is the outside.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

16. Neurotransmitters Oxytocin
both a hormone and a neurotransmitter
related to onset of lactation in new mothers
related to attachment/emotional bonds
Note: Drugs can interfere with neurotransmitters
mimics or enhances NT effects
blocks effects of NT
IM: Handout 3.2: What’s in your Medicine Cabinet?
© 2011 The McGraw-Hill Companies, Inc.

17. Action Potential
Action potential occurs when the membrane potential rapidly shifts from to +40 mV
Ion channels open in the membrane, allowing sodium ions to enter the axon
Sodium entry shifts the membrane potential toward a positive value
Potential is restored when other channels open, allowing potassium ions to exit the axon
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

18. The Action Potential © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

19. Action Potential Details
Action potentials vary in frequency (a few pulses per second to a max of 1000 pulses per second)
APs have a refractory period (about 1 msec)
AP is “all or none” in nature
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

20. Myelin
Myelin is a fatty, waxy substance coating the axon of some neurons.
Functions:
Speeds neurotransmission
Insulates neurons from each other
Makes neurotransmission more efficient
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

21. Brain imaging technologies
Positron Emission Tomography (PET)
Makes use of radioactive tracer to measure cerebral blood flow.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

22. Brain imaging technologies
Functional Magnetic Resonance Imaging (fMRI)
Uses electromagnets to measure oxygen levels in brain.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

23. Psychoactive Drugs
Psychoactive drugs affect the nervous system to alter mood, emotion, and thought
Psychoactive drugs act by:
Increasing or decreasing release of neurotransmitters
Stimulating or blocking receptor sites
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

24. Psychoactive Drugs Agonists enhance neurotransmitter function
Antagonists block neurotransmitter function
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

25. The Endocrine System
Hormones are secreted into the blood by the endocrine system
Hypothalamus controls hormone release
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

26. The Endocrine System Functions of the endocrine system:
Maintain homeostasis
2. Regulate reproductive system
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

27. Brain: Structure and Function
Note: Instructors may want to copy and reinsert this slide before or after discussing the hindbrain, midbrain, and forebrain
© 2011 The McGraw-Hill Companies, Inc.

28. Brainstem Brainstem is a primitive portion of brain
Pons: involved in respiration, sleep regulation, dreaming
Medulla: involved in life support functions such as respiration and heart rate
Reticular activating system is an arousal system within the brainstem
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

29. Subcortical Brain Areas
Corpus callosum: band of axons that interconnects the hemispheres
Thalamus: sensory relay area
Limbic system: involved in emotionality
Hypothalamus: feeding, fleeing, mating, fighting, homeostasis
Cerebellum: involved in motor control
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

30. Limbic System: Seat of Motivation, Emotions
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

31. Limbic System © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

32. Cerebral Cortex
© 2011 The McGraw-Hill Companies, Inc.

33. Cerebral Cortex Cortex refers to the outer covering of the brain
Consists of left and right hemispheres
Cortex is divided into lobes
Frontal: Self-awareness, planning, voluntary movement, emotional control, speech, working memory
Parietal: Body sensations
Occipital: Vision
Temporal: Hearing, language comprehension
Localization of function: do discrete circuits carry out different functions?
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

34. Cortical Lobes © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

35. Language areas: Broca & Wernicke
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

36. LeDoux’s two pathways of emotion
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

37. Summary of Hemispheric Specializations
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

38. Motor and Somatosensory Cortex
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

39. Split-Brain Research
When a split-brain patient is asked to stare straight ahead while a photo of a fork is flashed to his left visual field, he cannot name it.
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

40. Split-Brain Research © 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

41. Behavioral Genetics
Behavioral genetics examines the influence of genes (versus environment) on behavior
Research strategies:
Twin studies: compare the concordance (agreement) rates between identical and fraternal twins
Adoption studies: compare the similarity between adopted children and their biological/adopted parents
Mutations: examine behaviors in genetically abnormal subjects or in animals in which a specific gene has been “knocked out”
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E

42. Evolutionary Psychology
Darwin argued that natural forces select traits that are adaptive for survival
Natural selection: certain traits are passed on because these traits gave an advantage for survival
Organisms with these traits are able to reproduce and pass on the trait to their offspring
Genetic mutations can be beneficial or disastrous
Evolutionary psychology examines how evolutionary processes impact behavior
© 2004 John Wiley & Sons, Inc.
Huffman: PSYCHOLOGY IN ACTION, 7E