1. Chapter 7 The Central Nervous System
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 7 The Central Nervous System
Slides 7.26 – 7.62
Lecture Slides in PowerPoint by Jerry L. Cook
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2. Central Nervous System (CNS)
Characteristics:
Size: two fistfuls of pinkish grey tissue
Weighs approx. 3 lbs.
Filled with cerebrospinal fluid
Four major regions – cerebral hemispheres, diencephalon, brain stem and cerebellum
Slide 7.26
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3. Four Major Regions of the Brain
Cerebral hemispheres
Diencephalon
Brain stem
Cerebellum
Figure 7.12
Slide 7.27
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4. Cerebral Hemispheres (Cerebrum)
The entire surface is made of ridges (gyri) and seperated by grooves (sulci)
Figure 7.13a
Slide 7.28b
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5. Lobes of the Cerebrum
Fissures (deep grooves) divide the cerebrum into lobes
Surface lobes of the cerebrum
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Slide 7.29a
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6. Lobes of the Cerebrum Figure 7.15a Slide 7.29b
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7. Specialized Areas of the Cerebrum
(Speech, memory, logical and emotional response, consciousness, intrepretation of sensation, voluntary movement)
Somatic sensory area (parietal lobe)– receives impulses from the body’s sensory receptors
Allows you to recognize pain, coldness, light touch
Slide 7.30
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8. Primary motor area – sends impulses to skeletal muscles
Allows us to consciously move our skeletal muscles

9. Broca’s area – involved in our ability to speak

10. Sensory and Motor Areas of the Cerebral Cortex
Figure 7.14
Slide 7.31
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11. Diencephalon Sits on top of the brain stem
Enclosed by the cerebral heispheres
Made of three parts:
Thalamus
Hypothalamus
Epithalamus
Slide 7.34a

12. Brain Stem Attaches to the spinal cord Parts of the brain stem
Midbrain
Pons
Medulla oblongata
Slide 7.38a
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13. Cerebrospinal Fluid Similar to blood plasma composition
Formed by the choroid plexus
Forms a watery cushion to protect the brain
Circulated in arachnoid space, ventricles, and central canal of the spinal cord
Slide 7.46
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14. Ventricles and Location of the Cerebrospinal Fluid
Figure 7.17b
Slide 7.47b
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15. Blood Brain Barrier
Includes the least permeable capillaries of the body
Excludes many potentially harmful substances
Useless against some substances
Fats and fat soluble molecules
Respiratory gases
Alcohol
Nicotine
Anesthesia
Slide 7.48
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16. Traumatic Brain Injuries
Concussion
Slight brain injury
No permanent brain damage
Contusion
Nervous tissue destruction occurs
Nervous tissue does not regenerate
Cerebral edema
Swelling from the inflammatory response
May compress and kill brain tissue
Slide 7.49
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17. Cerebrovascular Accident (CVA)
Commonly called a stroke
The result of a ruptured blood vessel supplying a region of the brain
Brain tissue supplied with oxygen from that blood source dies
Loss of some functions or death may result
Slide 7.50
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18. Alzheimer’s Disease Progressive degenerative brain disease
Mostly seen in the elderly, but may begin in middle age
Structural changes in the brain include abnormal protein deposits and twisted fibers within neurons
Victims experience memory loss, irritability, confusion and ultimately, hallucinations and death
Slide 7.51
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19. Cranial Nerves 12 pairs of nerves that mostly serve the head and neck
Numbered in order, front to back
Most are mixed nerves, but three are sensory only
Slide 7.58
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20. Distribution of Cranial Nerves
Figure 7.21
Slide 7.59
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21. Cranial Nerves I Olfactory nerve – sensory for smell
II Optic nerve – sensory for vision
III Oculomotor nerve – motor fibers to eye muscles
IV Trochlear – motor fiber to eye muscles
Slide 7.60
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22. Cranial Nerves
V Trigeminal nerve – sensory for the face; motor fibers to chewing muscles
VI Abducens nerve – motor fibers to eye muscles
VII Facial nerve – sensory for taste; motor fibers to the face
VIII Vestibulocochlear nerve – sensory for balance and hearing
Slide 7.61
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23. Cranial Nerves
IX Glossopharyngeal nerve – sensory for taste; motor fibers to the pharynx
X Vagus nerves – sensory and motor fibers for pharynx, larynx, and viscera
XI Accessory nerve – motor fibers to neck and upper back
XII Hypoglossal nerve – motor fibers to tongue
Slide 7.62
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