1. Anatomy of the Brain and Cranial Nerves 1

2. The Nervous System can be divided in: Central Nervous System (CNS)  Brain and Spinal Cord Peripheral Nervous System (PNS)  Cranial and spinal nerves, ganglia, sensory receptors 2

3. Division of the Peripheral Nervous System Sensory or afferent  Somatic  Visceral Motor or efferent  Somatic - voluntary  Visceral or Autonomic Nervous System (ANS) - involuntary Sympathetic Parasympathetic 3

4. Six regions in the adult brain  Cerebrum  Diencephalon  Mesencephalon  Pons  Cerebellum  Medulla oblongata Brain contains extensive areas of neural cortex  Layer of gray matter on the surface of the cerebellum and cerebrum Major regions and landmarks 4

5. The Cerebrum 5

6. Surface contains gyri, sulci, fissures Fissures  Longitudinal fissure separates two cerebral hemispheres  Transverse fissure separates cerebellum from cerebrum The cerebral hemispheres 6

7. The Cerebrum 7

8. The cerebral hemispheres Sulci  Parieto-occipital sulcus separates parietal from occipital lobe  Lateral sulcus separates temporal from parietal lobe  Central sulcus separates frontal and parietal lobe 8

9. The cerebral hemispheres Gyri  Precentral gyrus  Poscentral gyrus 9

10. The cerebral lobes Frontal  Precentral gyrus Primary motor area – conscious control of voluntary movements.  Premotor cortex – memory bank for skilled motor activities or of patterned and repetitious nature.  Broca’s area Located on the left hemisphere. Controls speech. 10

11. The cerebral lobes  Prefrontal cortex – responsible for personality, cognition, intellect. Lesion cause mental and personality disorder Parietal  Primary Somatosensory Area – touch, pressure, temperature, vibration, and pain from body wall  Somatosensory association area – interprets stimulus sent by the above area. Ex: recognizes objects by touch. 11

12. The cerebral lobes Temporal  Primary Auditory area – temporal lobe.  Primary association auditory area – interprets the sound heard by above area  Wernicke’s area – only on left hemisphere, between parietal and temporal lobes. Area responsible for understanding spoken language  Olfactory area –uncus. Smell area. 12

13. The cerebral lobes Occipital  Primary visual area – perception of light  Visual association area – interprets the images seen on the area above Insula  Gustatory cortex 13

14. Cerebral hemispheres - internal structures Gray matter  Cell bodies of the neurons  Dendrites  Small unmyelinated axons  Neuroglias 14

15. Cerebral hemispheres - internal structures White matter  Tracts Association – connects 2 areas of the same hemisphere Projection – connects upper and lower brain. Ex: internal capsule Commissure – connects the 2 hemispheres. 15

16. Tracts 16

17. Sagittal Section 17

18. Cerebral hemispheres - internal structures Corpus callosum  Connects the 2 hemispheres Fornix  Connects limbic system areas Septum pellucidum  Separates the 2 lateral ventricles 18

19. Cerebral hemispheres - internal structures Basal Nuclei – regulation of voluntary motor activities. Allows smooth movements.  Caudate Nucleus  Putamen  Globus pallidus 19

20. The Diencephalon 20

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23. Diencephalon: external view Olfactory tract Olfactory bulb Optic nerve Chiasma optic Pituitary gland or hypophysis Mammilary bodies – relay for olfaction 23

24. Epithalamus Hypothalamus Thalamus The diencephalon is composed of 24

25. Figure 14.12b Sagittal Section 25

26. The Epithalamus Roof of the third ventricle Contains choroid plexus Contains pineal gland  Regulates sleep-awake cycle 26

27. Relay area for impulses Two large lobes of gray matter Interthalamic adhesion or intermediate mass The thalamus 27

28. Autonomic center for regulation of body temperature, water balance, etc Secretes hormones Mammilary bodies – relay station for olfaction Pituitary glands – secretes hormones Optic chiasm The hypothalamus 28

29. The Brain Stem Midbrain  Cerebral Aqueduct – connects third and forth ventricles  Cerebral peduncles – connects pons to cerebrum  Corpora quadrigemina Superior colliculi – visual reflex center Inferior colliculi – auditory reflex center 29

30. The Brain Stem Pons  Consists of tracts and nuclei  Connects brain to lower CNS Medulla Oblongata Tracts Decussation of the pyramids Autonomic reflex centers – heart rate, blood pressure, vomiting, swallowing, respiratory rhythm Olives 30

31. PART 2 31

32. Cerebellum Two hemispheres connected by the vermis Arbor vitae – white matter Cortex of gray matter 32

33. The Cerebellum 33

34. The Cerebellum 34

35.  Dura mater Falx cerebri-formed by dura mater that dips into the longitudinal fissure and separates the 2 hemispheres Falx cerebelli – separate the two cerebellar hemispheres The cranial meninges 35

36. The cranial meninges – dura mater Superior sagittal Sinus – collects blood from the brain Tentorium cerebelli – separates the cerebrum from the cerebellum 36

37. The cranial meninges Arachnoid  Subarachnoid space Filled with CSF  Arachnoid villi – projections of the mater that protrude through the dura For the CSF to drain back to the venous circulation 37

38. The cranial meninges Pia mater  Highly vascular  Covers the entire brain Meningites 38

39. The Relationship among the Brain, Cranium, and Meninges 39

40. Filled with cerebrospinal fluid (CSF) Lateral ventricles  Septum pellucidum  Interventricular foramina or foramen of Monro Ventricles of the brain 40

41. Ventricles of the brain Third ventricle  Cerebral aqueduct Forth ventricle  3 Apertures 41

42. Ventricles of the Brain 42

43. CSF cushions delicate neural structures Supports the brain Pathway of CSF  Produced at the Choroid plexus  Travels through the apertures on the 4 th ventricle to the subarachnoid space  Diffuses across the arachnoid villus (granulation) into the superior sagittal sinus Cerebrospinal fluid (CSF) 43

44. The Circulation of CSF 44

45. 12 pairs of cranial nerves To help to remember “Old Opie Occasionally Tries Trigonometry And Fells Very Gloomy Vague And Hypoactive ” Cranial Nerves 45

46. The Cranial Nerves PLAY 46

47. Cranial Nerves NumberNameMajor Functions IOlfactory (sens)Smell IIOptic (sens)Vision IIIOculomotor (mot) Eye movement IVTrochlear (mot)Eye movement VTrigeminal (mix)Chewing muscles, head and face sensation 47

48. Cranial nerves VIAbducens (mot)Eye movement VIIFacial (mix)Face expression, taste VIIIVestibulocochlear (sen) Vestibular: posture and balance Cochlear: hearing 48

49. Cranial Nerves IXGlossopharingeal (mix) Swallowing, taste, general sensation for pharynx XVagus (mix)Visceral muscle movement and taste sensation XIAccessory (mot)Swallowing, and head movement XIIHypoglossal (mot) Movement of tongue for speaking, swallowing and mixing food 49

50. Brain Dissection Whole Brain Pia-Arachnoid Gyrus Sulcus Fissure  Transverse  Longitudinal Cerebrum 50

51. Brain Dissection Pons Medulla Oblongata Cerebellum Cranial nerves: I (bulb, tract) II (nerve, chiasma) III 51

52. Brain Dissection Colliculi  Superior  Inferior Pineal Gland 52

53. Brain Dissection Sagittal Cut Diencephalon  Epithalamus  Thalamus  Hypothalamus Ventricles  Lateral, third, forth 53

54. Brain Dissection Septum pellucidum Corpus callosum Fornix Arbor vitae (cerebellum) 54