AP Psychology: Introduction to Neuroscience

1. AP Psychology: Introduction to Neuroscience September 28, 2010 Ms. Simon

2. Do Now: Fact or Falsehood

3. Neuron • Nerve cell, smallest functional unit of the nervous system

8. Kinds of Neurons Sensory/Afferent Neurons carry incoming information from the sense receptors to the CNS. Motor/Efferent Neuronscarry outgoing information from the CNS to muscles and glands. Interneurons connect the two neurons. Primarily located in the spinal cord Sensory Neuron Interneuron Neuron (Unipolar) Motor Neuron

9. Sensory Neuron  Interneuron  Motor Neuron

10. What are the parts of the neuron?

11. Dendrites Receive stimulus from sensory organs and other neurons

12. Soma The soma is the cell body and contains the nucleus

13. Axon The axon sends signal away from the cell body

14. Terminal Branches Contain terminal buttons, synaptic knobs and form synapses with other cells

15. Myelin • Myelin- fatty covering that wraps around the axons of Schwann cells

16. Kinds of Neurons Sensory Neurons carry incoming information from the sense receptors to the CNS. (afferent) Motor Neuronscarry outgoing information from the CNS to muscles and glands. Interneurons connect the two neurons. (efferent) Sensory Neuron (Bipolar) Interneuron Neuron (Unipolar) Motor Neuron (Multipolar)

17. Action potentials • Brief Electrical charge that travels down an axon Neurotransmitters: Chemicals that transmit messages between neurons

18. Neural Transmission • Electrical impulses allow for the transmission of information within a neuron • Chemical impulses allow for transmission of information between neurons

19. Neural transmission: How does an electrical impulse flow through the neuron? • An electrical impulse is a rapid movement of charged particles down the axon, also known as an action potential • At resting state, there are large concentrations of K+ ions inside the neuron • Large concentration of Na+ ions outside the neuron

20. Electrical Impulses

21. Do Now • Pass forward Psych Sims • How is a neuron similar to an electrical wire?

22. AIM: How are signals transmitted through the nervous system?

23. I. Action potentials • Domino Effect

24. Excitatory signals must exceed a minimum intensity, or threshold, for an action potential to fire All-or-None Principle

25. A. Resting State • Outside of the neuron membrane is positive • Inside of the membrane is negative (-70 mV) • More Na+ outside, more K+ inside Why don’t the charges escape? 4. The membrane is selectively permeable

26. Selectively permeable

27. B. Depolarization (Rising Phase) Causes the inside of the membrane to become positively charged (depolarized)

28. 2) Repolarization (Falling Phase of Action Potential)

29. 3) Hyperpolarization

30. Short amount of time when no new action potentials can be fired Resting potential (-70 mV) must Be restored 4) Refractory Period

31. Nerve Cell Membrane • Each level contains about 10% o the energy in the previous level.

32. Voltage of Membrane

33. What happens when the action potential reaches the end of the neuron? http://www.youtube.com/watch?v=DF04XPBj5uc http://www.youtube.com/watch?v=90cj4NX87Yk&feature=related

34. How do neurons communicate? • Neurotransmitters- are released at the terminal branch into the synapse Neurotransmitters bind to the postsynaptic receptor

35. Neurotransmitters bind receptors in a lock-and-key model

36. Neurotransmitters • Neurotransmitters can have an excitatory or inhibitory effect • Excitatory- cause action potential to fire • Inhibitory- prevent action potential from firing

37. AIM: How do neurotransmitters affect the nervous system?

38. What happens when the action potential reaches the terminal branch? • Vesicles containing neurotransmitters are released into the synapse • Neurotransmitters bind to postsynaptic receptors • Cause excitatory or inhibitory effects http://www.youtube.com/watch?v=Ntenaz7Sf4k

39. Signals into the neuron • Inhibitory: cause neuron to become hyperpolarized • Hyperolarized =Inhibitory • Excitatory: cause neuron to become depolarized • Excitatory= depolarized

40. What are the different neurotransmitters?

41. Agonists and Antagonist Agonists- “excites” mimics the effects of a neurotransmitter example: morphine Antagonists- “inhibit” - inhibits release of neurotransmitter or binds to receptor and blocks its function example: curare

42. These natural opiates are released in response to pain and vigorous exercise? • Acetylcholine is known to be involved in ____________________ (name one function) • Why can’t we just flood the brain with opiates such as morphine? • What is an antagonist?

44. What are the divisions of the nervous system?

45. Nervous System Peripheral Nervous System (PNS) Motor and Sensory neurons Central Nervous System (CNS) = interneuron

46. The Nervous System 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.

47. The Nervous System

48. Peripheral Nervous System Somatic Nervous System:The division of the peripheral nervous system that controls the body’s skeletal muscles. Autonomic Nervous System: Part of the PNS that controls the glands and other muscles.

49. The Nerves Nerves consist of neural “cables” containing many axons. They are part of the peripheral nervous system

50. Autonomic Nervous System (ANS) Sympathetic Nervous System: Division of the ANS that arouses the body, mobilizing its energy in stressful situations. (Fight or flight) Parasympathetic Nervous System: Division of the ANS that calms the body, conserving its energy. (Rest and Digest)