Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS)  CNS develops from the embryonic neural tube  Neural tube becomes brain and spinal cord  Brain Appearance: pinkish gray tissue, wrinkled like a walnut, texture of cold oatmeal  Brain Weight: a little over 3 pounds

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Major Regions of the Brain  Cerebral Hemispheres (Cerebrum)  Diencephalon  Brain Stem  Cerebellum

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Central Nervous System (CNS) Figure 7.12a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.12b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebral Hemispheres: AKA “Cerebrum”  Paired (left and right) superior parts of the brain  Includes more than half of the brain mass & encloses the brain stem  The surface is made of elevated ridges called gyri and shallow grooves called sulci

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Hemispheres separated by a single deep fissure = “longitudinal fissure”  Other fissures (deep grooves) divide the cerebrum into lobes  Surface lobes of the cerebrum:  Frontal lobe  Parietal lobe  Occipital lobe  Temporal lobe

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.13b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum  Cerebrum’s 3 Basic Regions:  Superficial cerebral cortex of gray matter  Internal white matter  Basal nuclei

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebral Cortex  Outer gray matter of the cerebrum  Functions of neurons of the cerebral cortex:  Speech, memory, logical & emotional response, consciousness, interpretation of sensation, voluntary movement

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebral White Matter  Deeper tissue  Composed of fiber tracts carrying impulses to, from, or within the cortex  Large fiber tract = Corpus Callosum  Allows cerebral hemispheres to communicate with one another

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Basal Nuclei  Several “islands” of gray matter buried deep within the white matter  Regulate voluntary motor activities

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebrum Figure 7.15

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Functional Areas of Cerebrum (SG page 9) Figure 7.13c

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Structural Regions of the Brain (SG page 9) Figure 7.16

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Diencephalon  AKA Interbrain  Sits on top of the brain stem  Enclosed by the cerebral hemispheres

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon Figure 7.16a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Thalamus  Surrounds the third ventricle  The relay station for sensory impulses  Transfers impulses to the correct part of the cortex for localization and interpretation  We get the “pleasant or unpleasant” sensation as impulses pass here

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Hypothalamus  Under the thalamus  Important autonomic nervous system center  Helps regulate body temperature  Controls water balance  Regulates metabolism  An important part of the limbic system (emotions)  The pituitary gland is attached to the hypothalamus

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Diencephalon  Epithalamus  Forms the roof of the third ventricle  Houses the pineal body (an endocrine gland)  Includes the choroid plexus—forms cerebrospinal fluid

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Brain Stem  The size of a thumb in diameter & 3 inches long  Attaches to the spinal cord  Is the pathway of ascending & descending nerve tracts

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem Figure 7.16a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Midbrain  Mostly composed of tracts of nerve fibers  Cerebral aqueduct connects 3 rd & 4 th ventricles  Has two bulging fiber tracts— cerebral peduncles  Has four rounded protrusions— corpora quadrigemina  Reflex centers for vision and hearing

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Pons  The bulging center part of the brain stem  Mostly composed of fiber tracts  Includes nuclei involved in the control of breathing

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Medulla Oblongata  The lowest part of the brain stem  Merges into the spinal cord  Contains important fiber tracts & control centers:  Heart rate control  Blood pressure regulation  Breathing  Swallowing  Vomiting

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Brain Stem  Reticular Formation  Diffuse mass of gray matter along the brain stem  Involved in motor control of visceral organs  Reticular activating system (RAS) plays a role in awake/sleep cycles and consciousness  Damage here results in a coma

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Reticular Formation of the Brain Stem Figure 7.16b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebellum  Projects dorsally under occipital lobe  Two hemispheres with convoluted surfaces  Provides timing for skeletal muscle activity & controls balance & equilibrium  Ataxia  Damage to cerebellum by blow to head, tumor, or stroke causes movements to become clumsy & disorganized  Appear drunk because of loss of muscle coordination

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Regions of the Brain: Cerebellum Figure 7.16a