1. Chapter 7 The Nervous System
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 7 The Nervous System
Slides 7.23 – 7.42
Lecture Slides in PowerPoint by Jerry L. Cook
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2. The Reflex Arc
Reflex – rapid, predictable, and involuntary responses to stimuli
Reflex arc – direct route from a sensory neuron, to an interneuron, to an effector
Figure 7.11a
Slide 7.23
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3. Simple Reflex Arc Figure 7.11b, c Slide 7.24
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4. Types of Reflexes and Regulation
Autonomic reflexes
Smooth muscle regulation
Heart and blood pressure regulation
Regulation of glands
Digestive system regulation
Somatic reflexes
Activation of skeletal muscles
Slide 7.25
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5. Central Nervous System (CNS)
CNS develops from the embryonic neural tube
The neural tube becomes the brain and spinal cord
The opening of the neural tube becomes the ventricles
Four chambers within the brain
Filled with cerebrospinal fluid
Slide 7.26
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6. Regions of the Brain Cerebral hemispheres Diencephalon Brain stem
Cerebellum
Figure 7.12
Slide 7.27
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7. Cerebral Hemispheres (Cerebrum)
Paired (left and right) superior parts of the brain
Include more than half of the brain mass
Figure 7.13a
Slide 7.28a
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8. Cerebral Hemispheres (Cerebrum)
The surface is made of ridges (gyri) and grooves (sulci)
Figure 7.13a
Slide 7.28b
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9. 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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10. Lobes of the Cerebrum Figure 7.15a Slide 7.29b
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11. Specialized Areas of the Cerebrum
Somatic sensory area – receives impulses from the body’s sensory receptors (parietal lobe)
Primary motor area – sends impulses to skeletal muscles (frontal lobe)
Broca’s area – involved in our ability to speak (frontal lobe)
Slide 7.30
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12. Sensory and Motor Areas of the Cerebral Cortex
Figure 7.14
Slide 7.31
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13. Specialized Area of the Cerebrum
Cerebral areas involved in special senses
Gustatory area (taste)
Visual area
Auditory area
Olfactory area
Slide 7.32a
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14. Specialized Area of the Cerebrum
Interpretation areas of the cerebrum
Speech/language region
Language comprehension region
General interpretation area
Slide 7.32b
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15. Specialized Area of the Cerebrum
Figure 7.13c
Slide 7.32c
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16. Layers of the Cerebrum Gray matter Outer layer
Composed mostly of neuron cell bodies
Cerebral Cortex
Figure 7.13a
Slide 7.33a
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17. Functions of the Cerebral Cortex
Speech
Memory
Logical and emotional response
Consciousness
Interpretation of sensation
Voluntary movement
Slide 7.32b
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18. Layers of the Cerebrum White matter
Fiber tracts inside the gray matter
Example: corpus callosum connects hemispheres-allows communication
Figure 7.13a
Slide 7.33b
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19. Layers of the Cerebrum Basal nuclei – internal islands of gray matter
Figure 7.13a
Slide 7.33c
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20. Diencephalon Sits on top of the brain stem
Enclosed by the cerebral hemispheres
Made of three parts
Thalamus
Hypothalamus
Epithalamus
Slide 7.34a
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21. Diencephalon Figure 7.15 Slide 7.34b
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22. Thalamus Surrounds the third ventricle
The relay station for sensory impulses
Transfers impulses to the correct part of the cortex for localization and interpretation
Slide 7.35
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23. Hypothalamus Under the thalamus
Important autonomic nervous system center
Helps regulate body temperature
Controls water balance
Regulates metabolism
Slide 7.36a
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24. Hypothalamus An important part of the limbic system (emotions)
The pituitary gland (endocrine gland) is attached to the hypothalamus
Slide 7.36b
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25. Epithalamus Forms the roof of the third ventricle
Houses the pineal body (an endocrine gland)
Includes the choroid plexus – forms cerebrospinal fluid
Slide 7.37
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26. Brain Stem Attaches to the spinal cord Parts of the brain stem
Midbrain
Pons
Medulla oblongata
Slide 7.38a
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27. Brain Stem Figure 7.15a Slide 7.38b
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28. Midbrain Mostly composed of tracts of nerve fibers
Has two bulging fiber tracts – cerebral peduncles
Ascending and descending impulses
Has four rounded protrusions – corpora quadrigemina
Reflex centers for vision and hearing
Slide 7.39
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29. Pons The bulging center part of the brain stem
Mostly composed of fiber tracts
Includes nuclei involved in the control of breathing
Slide 7.40
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30. Medulla Oblongata The lowest part of the brain stem
Merges into the spinal cord
Includes important fiber tracts
Contains important control centers
Heart rate control
Blood pressure regulation
Breathing
Swallowing
Vomiting
Slide 7.41
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32. Reticular Formation Diffuse mass of gray matter along the brain stem
Involved in motor control of visceral organs
Reticular activating system plays a role in awake/sleep cycles and consciousness
Slide 7.42a
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33. Reticular Formation Figure 7.15b Slide 7.42b
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