1. Neurons I bet your neurons are all fired up now!

2. The Nervous System NEURON = 1 cell Example : Afferent, Efferent and Interneurons  Nerve = a bundle of neurons Example: Optic Nerve, Auditory Nerve

3. Types of Neurons Efferent (Motor) Neurons - carry outgoing messages from the brain and spinal cord to the muscles and glands Interneurons - neurons within the brain and spinal cord that communicate internally and between sensory inputs and motor outputs Afferent (Sensory) Neurons - carry messages from tissues and sensory organs to the brain and spinal cord for processing

4. Neurons

11. Parts of a Neuron Synapse (space between the neuron where chemical messages are sent to dendrites of other cells)

12. Neurons

13. How neurons communicate Neurons use an electro-chemical process to send messages Why electrical? – Pushing information through axon is based on process of positive and negative charges of electrical atoms (ions) Potassium (K+), Sodium (Na+), Chloride (Cl-) Why chemical? – Neurotransmitters (chemicals) cross the synapse: different ones send different impulses and need to find receptors – It can either excite (fire) or inhibit (prevent firing) Messages are sent at a speed of 2-200 mph Neurons are altered with use (learning) – unused neurons die (“neural sculpting)

14. How does a neuron fire The electrical impulse is called the action potential Step 1 - Resting potential – neuron is charged and ready to fire – Polarized – positive outside, negative inside (Na+) (Cl- & K+) – Selectively permeable – gates do not allow sodium ions to pass through the cell membrane Step 2 - Action potential – brief electrical charge that travels down the neuron – Transmits neural messages to other neurons, muscles or glands – When stimulated – depolarizes Sodium (Na+) rushes in Step 3 - Repolarization – Potassium (Ka+) flows out repolarizing the Axon. Step 4 – Refractory Period – brief period of time when neuron won’t fire no matter how much stimulation Sodium/Potassium pumps push Sodium (Na+) out and Potassium in (Ka+) bringing axon back to a resting state

15. Action Potential

20. Electrical Transmission – The Action Potential http://outreach.mcb.har vard.edu/animations/ac tionpotential_short.swf

21. How to generate a neural impulse 1.Neuron is stimulated by light, heat, pressure or chemical messages (neurotransmitters) from other neurons. 2.S ignals from other neurons are either – Excitatory - tell neuron to fire (brings neuron closer to firing – Inhibitory - tell neuron not to fire (brings neuron further away from firing) – (excitatory) – (inhibitory) reach minimum threshold, (minimum energy needed for a neuron to fire) an action potential will occur 3.All or None Law – once the neuron fires the impulse moves down the action potential at the same intensity—it can’t be stopped

22. A brief electrical charge that travels down the axon of a neuron is called the 1.Synapse 2.Agonist 3.Action Potential 4.Resting Potential 5.Refractory period 1234567891011121314151617181920 21222324252627282930

23. What disease is related to degeneration of the neuron’s myelin sheath? 1.A. parkinson’s disease. 2.B. Multiple sclerosis. 3.C. Alzheimer’s disease. 4.D. schizophrenia. 5.Huntington’s Disease 1234567891011121314151617181920 21222324252627282930

24. The function of dendrites is to 1.receive incoming signals from other neurons. 2.release neurotransmitters into the spatial junctions between neurons. 3.coordinate the activation of the parasympathetic and sympathetic nervous systems. 4.control pain through the release of opiate-like chemicals into the brain. 5.transmit signals to other neurons. 1234567891011121314151617181920 21222324252627282930

25. The movement of positively charged ions across the membrane of a neuron can produce a(n) 1.Action potential 2.Synapse 3.Neurotransmitter 4.Myelin sheath 5.Interneuron 1234567891011121314151617181920 21222324252627282930

26. The axon of a resting neuron has gates that do not allow positive sodium ions to pass through the cell membrane. What is this characteristic called? 1.Myelin sheath 2.Threshold 3.Selective permeability 4.Action potential 5.Refractory period 1234567891011121314151617181920 21222324252627282930

27. The minimum level of stimulation required to trigger a neural impulse is called the 1.Reflex 2.Threshold 3.Synapse 4.Action potential 5.All-or-none response 1234567891011121314151617181920 21222324252627282930

28. Dendrites are branching extensions of 1.Neurotransmitters 2.Endorphins 3.Neurons 4.Myelin 5.Endocrine Glands 1234567891011121314151617181920 21222324252627282930

29. How do neurons communicate with each other? The chemical process

30. How Neurons Communicate

35. Inhibition and Excitation Excitation – the process of making the neuron receiving neurotransmitters more likely to generate an action potential (fire) Inhibition – the process of making the neuron receiving neurotransmitters less likely to generate an action potential Excitation>Inhibition for neuron to fire Threshold – minimum stimulation for neuron to fire (-55 mV)

36. Synaptic Transmission http://learn.genetics.utah.e du/content/addiction/rewar d/neurontalk.html

37. Neurotransmitters Neurotransmitters – Chemical messengers in the brain. Different types affect the brain and behavior in various ways Excitatory neurotransmitters bring the dendrite closer to threshold by allowing positive ions to rush in. (ex. Glutamate) Inhibitory neurotransmitters take the dendrite further away from threshold by allowing negative ions to rush in (ex. GABA)

38. Drugs can be….. Agonists- mimic neurotransmitters Antagonists- block neurotransmitters Reuptake Inhibitors- block reuptake

39. Acetylcholine (ACH) Deals with motor movement, memory and learning. Too much and you will…. Too little and you will… Lack of AcH has been linked to Alzheimer’s disease. Black widow – increased AcH Botox – decreased AcH Curare – decreased AcH

40. Dopamine Deals with motor movement and alertness/attention, emotion, rewards. Lack of dopamine - linked to Parkinson’s disease. Too much - linked to schizophrenia.

41. Serotonin Regulates sleep, dreaming, mood, pain, aggression, appetite and sexual arousal Depression - Lack of serotonin Anorexia = too much Bulimia – too little

42. Endorphins Involved in pain control. “endorphins make you happy” – runners high (emotions) Drugs that mimic =. Agonists - Heroine, morphine, codeine

43. Norepenephrine Fight or flight response Helps control alertness and arousal Undersupply can depress mood

44. GABA Major inhibitory neurotransmitter meaning it keeps the neuron from firing (slows CNS) Undersupply linked to seizures, tremors, insomnia Alcohol consumption causes an increase in Gaba

45. Glutamate Major excitatory neurotransmitter Meaning… It causes neurons to fire – overactive CNS Oversupply can over stimulate brain, producing migraines or seizures MSG

46. Drugs can be….. Agonists- mimic neurotransmitters Antagonists- block neurotransmitters Reuptake Inhibitors- block reuptake

47. Agonists and Antagonists http://thebrain.mcgill.ca/flash/i/i_03/i_03_m/ i_03_m_par/i_03_m_par_cocaine.html#dro gues

48. Agonist and Antagonists Examples: Agonists – Opiate Drugs Heroine, Morphine (Endorphins) Black Widow Spider Venom (AcH) Antagonists – Botulin (AcH), Botox (AcH), Curare (AcH)

49. Reuptake refers to the 1.movement of neurotransmitter molecules across a synaptic gap. 2.release of hormones into the bloodstream. 3.inflow of positively charged ions through an axon membrane. 4.reabsorption of excess neurotransmitter molecules by a sending neuron. 5.the ending of the refractory period.

50. Antidepressants such as Prozac target which neurotransmitter? 1.A. serotonin. 2.B. glutamate. 3.C. GABA. 4.D. acetylcholine. 5.Dopamine

51. Lindsey has just played a long volleyball match after injuring her ankle in the first game, but feels little fatigue or discomfort. Her lack of pain is most likely caused by the release of 1.Glutamate 2.Dopamine 3.Acetylcholine 4.Endorphins 5.Insuline 1234567891011121314151617181920 21222324252627282930

52. A person with schizophrenia may have an overactive dopamine system. Drugs used to treat this disorder prevent the action of dopamine by keeping it from binding to its receptors. These drugs are 1.Agonists 2.Reuptakes 3.Action Potentials 4.Antagonists 5.Synapses

53. Neurotransmitters that bring a neuron closer to firing are called 1.Agonist 2.Antagonists 3.Inhibitory 4.Reuptake 5.Excitatory

54. The Nervous System

55. Central Nervous System Brain Spinal chord Interneurons

56. Peripheral Nervous System All nerves that are not encased in bone. Everything but the brain and spinal cord. Motor and Sensory Neurons Autonomic and Somatic

57. Somatic Nervous System Controls voluntary muscle movement. Uses motor (efferent) neurons.

58. Autonomic Nervous System Controls the automatic functions of the body. – Lungs, stomach, intestines, liver, kidney, heart sympathetic and the parasympathetic

59. Sympathetic Nervous System Fight or Flight Response. – Arouses and expends energy Causes: – Increase in heart rate, breathing, dilates pupils, slows down digestion, relaxes bladder

60. Parasympathetic Nervous System Rest and Digest Response Automatically slows the body down after a stressful event. Causes: – Heart rate and breathing slow down, pupils constrict and digestion speeds up.

62. The peripheral nervous system consists of: A. association areas. B. the spina chord. C. the reticular formation. D. sensory and motor neurons. 1234567891011121314151617181920 21222324252627282930

63. As Allison reaches for a box in her garage, out jumps a big spider. Her heart immediately begins to race as she withdraws her hand, but soon she realizes that the spider is harmless, and she begins to calm down. Which part of her nervous system is responsible for brining her back to a normal state of arousal? A. sympathetic nervous system B. somatic nervous system C. parasympathetic nervous system D.skeletal nervous system 1234567891011121314151617181920 21222324252627282930

64. Reflexes Reflex - a simple, automatic, inborn response to a sensory stimulus – Normally, sensory (afferent) neurons take info up through spine to the brain. – Some reactions occur when sensory neurons reach just the interneurons in the spinal cord = reflex – Survival adaptation.

65. A Simple Reflex

66. A Simplified Neural Network Neurons learn to work together as a team. Neurons that fire together, wire together = learning

67. The Endocrine System A system of glands that secrete hormones. Hormones are similar, but work a lot slower than neurotransmitters. Neurotransmitter nervous system Speed = fraction of a second Hormones blood stream Speed = several sec to travel from gland to tissue Messages outlast neurotransmitters Neurotransmitters Hormones

68. Figure 3A.11 The endocrine system © 2011 by Worth Publishers Master Gland:- controls other glands Responsible for releasing growth hormones Hypoglycemia – low blood glucose/sugar Hyperglycemia -High blood glucose/suger (diabetes) Overactive = too thin Underactive = too fat Controls pituitary gland Sends info to CNS Adrenaline or epinephrine and norepinephrine Estrogen Testosterone