7 PART B Part II Central Nervous System

7 PART B Part II Central Nervous System: Brain Power. Point® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Chapter 7 Vocabulary 31. 32. 33. 34. 35. ventricles gyri (gyrus) sulci (sulcus) fissures longitudinal fissure 36. central sulcus 37. Broco’s area 38. 39. 40. 41. 42. 43. speech area cerebral cortex corpus callosum Parkinson’s disease Huntington’s disease Alzheimer’s disease (AD) Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

II. 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 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventricles and Location of the Cerebrospinal Fluid Figure 7. 17 a–b Copyright © 2006

A. Four Major Regions of the Brain 1. Cerebrum (Cerebral hemispheres) 2. Diencephalon 3. Brain stem 4. Cerebellum Figure 7. 12 b Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral Hemispheres (Cerebrum) § Paired (left and right) superior parts of the brain § Include more than half of the brain mass Figure 7. 13 a Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral Hemispheres (Cerebrum) § The surface is made of ridges (gyri) and grooves (sulci) § Gyri (gyrus) – outward folds or ridges on surface of cerebral cortex § Sulci (sulcus) – shallow grooves or furrows in cerebral cortex § Fissures – the deepest inward folds on the brain Figure 7. 13 a Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral Hemispheres (Cerebrum) § Central Sulcus – divides the cerebral hemisphere into motor and sensory areas; separates the frontal lobe from the parietal lobe § Longitudinal Fissure separates the cerebral hemispheres Figure 7. 13 a Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

B. Cerebrum - Four Lobes § Fissures (deep grooves) divide the cerebrum into lobes: 1. Parietal lobe – somatic sensory area (postcentral sulcus) 2. Frontal lobe – primary motor area (pre-central sulcus), Broca’s area (motor speech) 3. Temporal lobe – auditory area and olfactory area 4. Occipital lobe – visual area Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Lobes of the Cerebrum Figure 7. 15 a Copyright © 2006 Pearson Education, Inc.

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 say words correctly; usually in left cerebral hemisphere (frontal lobe) § Speech Area – involved in language comprehension (word meanings); located at junction of temporal, parietal, and occipital lobes Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory and Motor Areas of the Cerebral Cortex Figure 7. 14 Copyright © 2006

Specialized Areas of the Cerebrum § Cerebral areas involved in special senses § Gustatory area (taste) § Visual area § Auditory area § Olfactory area Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Specialized Areas of the Cerebrum § Interpretation areas of the cerebrum § Speech/language region § Language comprehension region § General interpretation area Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Specialized Areas of the Cerebrum Figure 7. 13 c Copyright © 2006 Pearson Education,

Layers of the Cerebrum § Gray matter § Outer layer § Composed mostly of neuron cell bodies § Cerebral cortex – outermost gray matter of the cerebrum; Figure 7. 13 a Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Layers of the Cerebrum § White matter § Fiber tracts inside the gray matter § corpus callosum connects cerebral hemispheres Figure 7. 13 a Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

§Corpus Callosum – connects the cerebral hemispheres; allows the brain stem and cerebral hemispheres to communicate with one another corpus callosum Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Layers of the Cerebrum § Basal nuclei – internal islands of gray matter; help regulate voluntary motor activities by modifying instructions sent to the skeletal muscles by the primary motor cortex; § Located at the base of the brain § Composed of 4 clusters of neurons, or nerve cells. § This area of the brain is responsible for body movement and coordination. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 7. 13 a

The Terrible Three CNS Degenerative Diseases § Parkinson’s disease – degeneration of dopamine-releasing neurons causing basal nuclei to become overactive, causing persistent tremor at rest and trouble initiating movement or getting muscles going § Huntington’s disease - genetic disease that leads to massive degeneration of the basal nuclei and later of the cerebral cortex. Symptoms are wild, jerky, and almost continuous flapping movements called chorea and mental deterioration, usually fatal, within 15 years of onset § Alzheimer’s disease (AD) – progressive degenerative disease of the brain that ultimately results in dementia (mental deterioration). AD is associated with a shortage of acetylcholine (ACh) and structural changes in the brain, particularly in areas involved with cognition and memory where abnormal proteins are deposited, gyri shrink, and the brain atrophies. Causes are unknown. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

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 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Alzheimer’s Disease (AD) Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Huntington’s Disease Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Huntington’s Disease § Huntington's disease is a hereditary disorder caused by a faulty gene for a protein called huntingtin. The children of people with the disorder have a 50% chance of inheriting it. The disease causes degeneration in many regions of the brain and spinal cord. Symptoms of Huntington's disease usually begin when patients are in their thirties or forties, and the average life expectancy after diagnosis is about 15 years. Cognitive symptoms of Huntington's disease typically begin with mild personality changes, such as irritability, anxiety, and depression, and progress to severe dementia. Many patients also show psychotic behavior. Huntington's disease causes chorea - involuntary jerky, arrhythmic movements of the body - as well as muscle weakness, clumsiness, and gait disturbances. Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Parkinson’s Disease Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Imaging Dementia-Mayo Clinic § http: //www. youtube. com/watch? v=b 6 i. OEeq. I 27

C. Diencephalon (Interbrain) § Sits on top of the brain stem § Enclosed by the cerebral hemispheres § Made of three parts: 1. Thalamus – relays sensory impulses 2. Hypothalamus – temperature, thirst, appetite, sex, pain, and pleasure center (limbic centeremotions); regulates pituitary gland mammillary bodies (sense of smell) 3. Epithalamus – contains pineal body (sleep/wake cycle) and choroid plexus (makes CS fluid) Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Diencephalon Figure 7. 15 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin

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 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

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 © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Diencephalon: Epithalamus § Forms the roof of the third ventricle § Houses the pineal body (an endocrine gland) § Includes the choroid plexus – forms cerebrospinal fluid Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

D. Brain Stem § Attaches to the spinal cord § Parts of the brain stem: 1. Midbrain – contains cerebral aqueduct, cerebral peduncles, and corpora quadrigemina; reflex centers for vision and hearing 2. Pons – “bridge”; controls breathing 3. Medulla oblongata – merges with spinal cord; vital centers control heart rate, blood pressure, breathing, swallowing and vomiting 4. Reticular formation – motor control of organs, RAS controls awake/sleep cycle and consciousness Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Brain Stem Figure 7. 15 a Copyright © 2006 Pearson Education, Inc. , publishing

Brain Stem: Midbrain § Mostly composed of tracts of nerve fibers § Has two bulging fiber tracts – cerebral peduncles § Has four rounded protrusions – corpora quadrigemina § Reflex centers for vision and hearing Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

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 © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Brain Stem: 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 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Brain Stem: 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 Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Brain Stem: Reticular Formation Figure 7. 15 b Copyright © 2006 Pearson Education, Inc.

E. Cerebellum § Two hemispheres with convoluted surfaces § Provides involuntary coordination of body movements § Precise timing for skeletal muscle activity § Controls balance and equilibrium Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebellum Figure 7. 15 a Copyright © 2006 Pearson Education, Inc. , publishing as

Traumatic Brain Injury Videos § Effects of damage to different lobes http: //www. youtube. com/watch? feature=play er_detailpage&v=wl. Yi. Dx. Nc. Mdc Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings

Chapter 7 Vocabulary 31. 32. 33. 34. 35. ventricles gyri (gyrus) sulci (sulcus) fissures longitudinal fissure 36. central sulcus 37. Broco’s area 38. 39. 40. 41. 42. 43. speech area cerebral cortex corpus callosum Parkinson’s disease Huntington’s disease Alzheimer’s disease (AD) Copyright © 2006 Pearson Education, Inc. , publishing as Benjamin Cummings