1. 14 The Brain and Cranial Nerves C h a p t e r
PowerPoint® Lecture Slides prepared by Jason LaPres
Lone Star College - North Harris
Copyright © 2009 Pearson Education, Inc.,
publishing as Pearson Benjamin Cummings

2. Major regions and landmarks
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

3. Figure The Adult Brain
Figure 14.1a, c

4. Figure The Adult Brain
Figure 14.1b

5. Figure The Adult Brain
Figure 14.1d

6. Figure 14.2 An Introduction to Brain Functions

7. Embryology of the brain
Brain forms from three swellings at the tip of the developing neural tube
Prosencephalon
Forms the telencephalon and eventually the cerebrum and diencephalon
Mesencephalon
Rhombencephalon
Forms the metencephalon (cerebellum and pons) and myelencephalon (medulla oblongata)

8. Ventricles of the brain
Central passageway of the brain enlarges to form ventricles
Contain cerebrospinal fluid (CSF)

9. Figure 14.3 Ventricles of the Brain
Figure 14.3a, b

10. The cranial meninges
Continuous with the three layers of the spinal cord
Folds of dura mater help stabilize the position of the brain
Falx cerebri
Tentorium cerebelli
Falx cerebelli

11. Figure 14.4 The Relationship among the Brain, Cranium, and Meninges
Figure 14.4a, b

12. Cerebrospinal fluid (CSF)
CSF cushions delicate neural structures
Supports the brain
Transports nutrients, chemical messengers, and waste products
Pathway of CSF
Produced at the Choroid plexus,
Travels through the lateral and medial apertures to the subarachnoid space,
Diffuses across the arachnoid granulations into the superior sagittal sinus

13. Figure 14.5 The Circulation of Cerebrospinal Fluid
Figure 14.5a, b

14. Blood supply to the brain
Blood brain barrier isolates neural tissue from general circulation
Incomplete barrier in areas
Parts of the hypothalamus
Pituitary gland
Pineal gland
Choroid plexus

15. Medulla oblongata Connects the brain with the spinal cord
Contains relay stations and reflex centers
Olivary nuclei
Cardiovascular and respiratory rhythmicity centers
Reticular formation begins in the medulla oblongata and extends into more superior portions of the brainstem

16. Figure 14.7 The Diencephalon and Brain Stem
Figure 14.7a, b

17. Figure 14.7 The Diencephalon and Brain Stem
Figure 14.7c

18. Figure 14.8 The Medulla Oblongata and Pons
Figure 14.8a, b

19. Figure 14.8 The Medulla Oblongata and Pons
Figure 14.8c

20. The pons contains Sensory and motor nuclei for four cranial nerves
Nuclei that help control respiration
Nuclei and tracts linking the cerebellum with the brain stem, cerebrum and spinal cord
Ascending, descending and transverse tracts

21. Figure 14.8 The Medulla Oblongata and Pons
Figure 14.8a, b

22. Figure 14.8 The Medulla Oblongata and Pons
Figure 14.8c

23. The cerebellum Adjusts postural muscles and tunes on-going movements
Cerebellar hemispheres
Anterior and posterior lobes
Vermis
Flocculonodular lobe
Superior, middle and inferior cerebellar peduncles link cerebellum with brain stem, diencephalon, cerebrum, and spinal cord
Interconnects the two cerebellar hemispheres

24. Figure The Cerebellum
Figure 14.9a

25. Figure The Cerebellum
Figure 14.9b

26. The mesencephalon The tectum (roof) contains the corpora quadrigemina
Superior and inferior colliculi
The mesencephalon contains many nuclei
Red nucleus
Substantia nigra
Cerebral peduncles
RAS headquarters

27. Figure 14.10 The Mesencephalon
Figure 14`10a, b

28. The diencephalon is composed of
Epithalamus
Hypothalamus
Thalamus

29. The thalamus Final relay point for ascending sensory information
Coordinates the activities of the cerebral cortex and basal nuclei

30. Figure The Thalamus
Figure 14.11

31. The hypothalamus
Controls somatic motor activities at the subconscious level
Controls autonomic function
Coordinates activities of the endocrine and nervous systems
Secretes hormones
Produces emotions and behavioral drives
Coordinates voluntary and autonomic functions
Regulates body temperature
Coordinates circadian cycles of activity

32. Figure 14.12 The Hypothalamus in Sagittal Section
Figure 14.12a

33. Figure 14.12 The Hypothalamus in Sagittal Section
Figure 14.12b

34. The limbic system or motivational system includes
Amygdaloid body
Cingulated gyrus
Parahippocampal gyrus
Hippocampus
Fornix
Functions of the limbic system involved emotions and behavioral drives

35. Figure 14.13 The Limbic System

36. Figure 14.14 The Brain in Section

37. The cerebral cortex Surface contains gyri and sulci or fissures
Longitudinal fissure separates two cerebral hemispheres
Central sulcus separates frontal and parietal lobes
Temporal and occipital lobes also bounded by sulci

38. White matter of the cerebrum
Contains association fibers
Commissural fibers
Projection fibers

39. Figure 14.15 The White Matter of the Cerebrum

40. The basal nuclei Caudate nucleus Globus pallidus Putamen
Control muscle tone and coordinate learned movement patterns

41. Motor and sensory areas of the cortex
Primary motor cortex of the precentral gyrus directs voluntary movements
Primary sensory cortex of the postcentral gyrus receives somatic sensory information
Touch
Pressure
Pain
Taste
Temperature

42. Figure 14.17 The Cerebral Hemispheres
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Figure 14.17

43. Association areas
Control our ability to understand sensory information and coordinate a response
Somatic sensory association area
Visual association area
Somatic motor association area

44. General interpretive and speech areas
General interpretive area
Receives information from all sensory areas
Present only in left hemisphere
Speech center
Regulates patterns of breathing and vocalization

45. Cortex functions and hemispheric differences
Prefrontal cortex
Coordinates information from secondary and special association areas
Performs abstract intellectual functions
Hemispheric differences
Left hemisphere typically contains general interpretive and speech centers and is responsible for language based skills
Right hemisphere is typically responsible for spatial relationships and analyses

46. Figure 14.18 Hemispheric Lateralization
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Figure 14.18

47. Electroencephalogram (EEG)
Measures brain activity
Alpha waves = healthy resting adult
Beta waves = concentrating adult
Theta waves = normal children
Delta waves = normal during sleep

48. Figure Brain Waves
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Figure 14.19a-d

49. Focus: Cranial Nerves 12 pairs of cranial nerves
Each attaches to the ventrolateral surface of the brainstem near the associated sensory or motor nuclei

50. Figure 14.20 Origins of the Cranial Nerves
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Figure 14.20a

51. Figure 13420 Origins of the Cranial Nerves
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Figure 14.20b

52. Figure 14.20 Origins of the Cranial Nerves
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Figure 14.20c

53. Olfactory nerves (I)
Carry sensory information responsible for the sense of smell
Synapse within the olfactory bulb

54. Figure 14.21 The Olfactory Nerve
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Figure 14.21

55. Cranial nerves II, III, IV
Optic nerves (II)
Carry visual information from special sensory receptors in the eyes
Occulomotor nerves (III)
Primary source of innervation for 4 of the extraocular muscles
Trochlear nerves (IV)
Innervate the superior oblique muscles

56. Figure 14.23 Cranial Nerves Controlling the Extra-ocular Muscles
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Figure 14.23

57. Cranial nerves V, VI, VII Trigeminal nerves (V)
Missed nerves with ophthalmic, maxillary and mandibular branches
Abducens nerve (VI)
Innervates the lateral rectus muscles
Facial nerves (VII)
Mixed nerves that control muscles of the face and scalp
Provide pressure sensations over the face
Receive taste information from the tongue

58. Figure 14.24 The Trigeminal Nerve
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Figure 14.24

59. Figure 14.25 The Facial Nerve
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Figure 14.25a, b

60. Cranial nerves VIII, IX Vestibulocochlear nerves (VIII)
Vestibular branch monitors balance, position and movement
Cochlear branch monitors hearing
Glossopharyngeal nerves (IX)
Mixed nerves that innervate the tongue and pharynx
Control the action of swallowing

61. Cranial nerves X Vagus nerves (X) Mixed nerves
Vital to the autonomic control of visceral function

62. Figure 14.26 The Vestibulocochlear Nerve
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Figure 14.26

63. Figure 14.27 The Glossopharyngeal Nerve
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Figure 14.27

64. Figure The Vagus Nerve
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Figure 13428

65. Cranial nerves XI, XII Accessory nerves (XI) Internal branches
Innervate voluntary swallowing muscles of the soft palate and pharynx
External branches
Control muscles associates with the pectoral girdle
Hypoglossal nerves (XII)
Provide voluntary motor control over tongue movement

66. Figure 14.29 The Accessory and Hypoglossal Nerve
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Figure 14.29

67. Cranial reflexes
Involve sensory and motor fibers of cranial nerves

68. You should now be familiar with:
The major regions of the brain and their functions.
The formation, circulation and functions of the CSF.
The main components of the medulla oblongata, the pons, the cerebellum, the mesencephalon, the diencephalon, and the limbic system and their functions.
The major anatomical subdivisions of the cerebrum.
The motor, sensory and association areas of the cerebral cortex.
Representative examples of cranial reflexes.