2. sensory receptor sensory input integration motor input effector

3. Central Nervous System (CNS) brainbrain spinal cordspinal cord Peripheral Nervous System (PNS) cranial nervescranial nerves spinal nervesspinal nerves

4. cell body dendrite Synapse axon Myelin sheath

5. Schwann Cells Axon Nodes of Ranvier

6. bipolar eye, ear, & olfactory unipolar multipolar most abundant type in CNS Dorsal root ganglion cells

7. sensory receptors sensory neuron interneuron motor neuron effector

8. A Simple Nerve Circuit – the Reflex Arc. –A reflex is an autonomic response.

9. Measuring Membrane Potentials. –An unstimulated cell usually have a resting potential of -70mV.

10. Ungated ion channels allow ions to diffuse across the plasma membrane. –These channels are always open.

11. Step 1: Resting State -70mV

12. Step 2: Threshold -50mV All or None Response

13. Step 3: Depolarization phase of the action potential. +45mV

14. Step 4: Repolarizing phase of the action potential.

15. Step 5: Undershoot: Hyperpolarization Gates slow to close

16. During the undershoot both the Na + channel’s activation and inactivation gates are closed. –At this time the neuron cannot depolarize in response to another stimulus: refractory period.

18. The action potential is repeatedly regenerated along the length of the axon. –An action potential achieved at one region of the membrane is sufficient to depolarize a neighboring region above threshold. Thus triggering a new action potential. The refractory period assures that impulse conduction is unidirectional. Nerve impulses propagate themselves along an axon

20. Saltatory conduction. –In myelinated neurons only unmyelinated regions of the axon depolarize. Thus, the impulse moves faster than in unmyelinated neurons.

21. Presynaptic neuron Postsynaptic membrane Ca 2+ Synaptic vesicles containing neurotransmitters

22. Excitatory postsynaptic potentials (EPSP) depolarize the postsynaptic neuron. –The binding of neurotransmitter to postsynaptic receptors open gated channels that allow Na + to diffuse into and K + to diffuse out of the cell. Neural integration occurs at the cellular level

23. Inhibitory postsynaptic potential (IPSP) hyperpolarize the postsynaptic neuron. –The binding of neurotransmitter to postsynaptic receptors open gated channels that allow K+ to diffuse out of the cell and/or Cl- to diffuse into the cell.

26. Acetylcholine- slows heart rate; PNS Glutamate- most prevalent neurotransmitter in the brain Aspartate- in CNS GABA- inhibitory neurotransmitter Glycine- inhibitory neurotransmitter Norepinephrine- awakening from deep sleep Epinephrine- increase heart rate Dopamine- movement of skeletal muscles Seratonin- sensory perception, temp regulation, mood, sleep Nitric oxide- may play a role in memory and learning Enkephalin- inhibit pain impulses by suppressing release of substance P Substance P- enhances perception of pain tyrosine

27. The ability of cells to respond to the environment has evolved over billions of years

28. Nerve nets. Nervous systems show diverse patterns of organization

29. With cephalization come more complex nervous systems.

30. brainspine

31. Functional composition of the PNS. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.17

33. Parasympathetic and Sympathetic Nervous System: A subdivision of the PNS Not under conscious control Work antagonistically Controlled by medulla oblongata and hypothalamus Peripheral nervous system that supplies stimulation via motor nerves to smooth and cardiac muscle and to glands

34. neurotransmitter is norepinephrine, fight or flight E = exercise, excitement, emergency, and embarrassment neurotransmitter is acetylcholine D = digestion, deification, diuresis (urinating)

39. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.20

40. cerebrum corpus callosum thalamus cerebellum medulla oblongata hypothalamus pituitary pons spinal cord Pineal gland

41. Cerebrum Involved with higher brain functions. Processes sensory information. Initiates motor functions. Integrates information.

42. The cerebrum is divided into frontal, temporal, occipital, and parietal lobes. Regions of the cerebrum are specialized for different functions

43. Frontal lobe. –Contains the primary motor cortex. Parietal lobe. –Contains the primary somatosensory cortex.

44. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.25

45. Integrative Function of the Association Areas. –Much of the cerebrum is given over to association areas. Areas where sensory information is integrated and assessed and motor responses are planned. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

46. The brain exhibits plasticity of function. –For example, infants with intractable epilepsy may have an entire cerebral hemisphere removed. The remaining hemisphere can provide the function normally provided by both hemispheres. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

47. Lateralization of Brain Function. –The left hemisphere. Specializes in language, math, logic operations, and the processing of serial sequences of information, and visual and auditory details. Specializes in detailed activities required for motor control. –The right hemisphere. Specializes in pattern recognition, spatial relationships, nonverbal ideation, emotional processing, and the parallel processing of information. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

48. Language and Speech. –Broca’s area. Usually located in the left hemisphere’s frontal lobe Responsible for speech production. –Wernicke’s area. Usually located in the right hemisphere’s temporal lobe Responsible for the comprehension of speech. –Other speech areas are involved generating verbs to match nouns, grouping together related words, etc. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

49. Emotions. –In mammals, the limbic system is composed of the hippocampus, olfactory cortex, inner portions of the cortex’s lobes, and parts of the thalamus and hypothalamus. Mediates basic emotions (fear, anger), involved in emotional bonding, establishes emotional memory –For example, the amygdala is involved in recognizing the emotional content of facial expression.

50. Memory and Learning. –Short-term memory stored in the frontal lobes. –The establishment of long-term memory involves the hippocampus. The transfer of information from short-term to long-term memory. –Is enhanced by repetition (remember that when you are preparing for an exam). –Influenced by emotional states mediated by the amygdala. –Influenced by association with previously stored information. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

51. –Different types of long-term memories are stored in different regions of the brain. –Memorization-type memory can be rapid. Primarily involves changes in the strength of existing nerve connections. –Learning of skills and procedures is slower. Appears to involves cellular mechanisms similar to those involved in brain growth and development. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

52. Human Consciousness. –Brain imaging can show neural activity associated with: Conscious perceptual choice Unconscious processing Memory retrieval Working memory. –Consciousness appears to be a whole- brain phenomenon. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

53. The mammalian PNS has the ability to repair itself, the CNS does not. –Research on nerve cell development and neural stem cells may be the future of treatment for damage to the CNS. Research on neuron development and neural stem cells may lead to new approaches for treating CNS injuries and diseases Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

54. Nerve Cell Development. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.28

55. Neural Stem Cells. –The adult human brain does produce new nerve cells. New nerve cells have been found in the hippocampus. Since mature human brain cells cannot undergo cell division the new cells must have arisen from stem cells. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

56. Thalamus Relay center for sensory tracts from the spinal cord to the cerebrum. Contains centers for sensation of pain, temperature, and touch. Involved with emotions and alerting or arousal mechanisms.

57. The Reticular System, Arousal, and Sleep. –The reticular activating system (RAS) of the reticular formation. Regulates sleep and arousal. Acts as a sensory filter. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.21

58. –Sleep and wakefulness produces patterns of electrical activity in the brain that can be recorded as an electroencephalogram (EEG). Most dreaming occurs during REM (rapid eye movement) sleep. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 48.22b-d

59. Hypothalamus autonomic control center- blood pressure, rate and force of heart contraction, center for emotional response and behaviorautonomic control center- blood pressure, rate and force of heart contraction, center for emotional response and behavior body temperaturebody temperature water balance and thirstwater balance and thirst sleep/wake cyclessleep/wake cycles appetiteappetite sexual arousalsexual arousal control of endocrine functioning:control of endocrine functioning: Acts on the pituitary gland through the release of neurosecretions. Regulates:

60. Hypothalamus

61. Pons Connects the two halves of the cerebellum. Regulates breathing.

62. Medulla Oblongata Composed of nerve tracts to and from the brain (these tracts cross over left to right and right to left) May be regarded as an extension of the spinal cord Almost all of the cranial nerves arise from this region

63. Medulla Oblongata Contains control centers for many subconscious activities Respiratory rate Respiratory rate Heart rate Heart rate Arteriole constriction Arteriole constriction Swallowing Swallowing Hiccupping Hiccupping Coughing Coughing Sneezing Sneezing

64. Cerebellum Controls and coordinates muscular activity. Important in equilibrium, posture and movement.