Nervous System:Brain and Cranial Nerves(Chapter 14)Lecture MaterialsforAmy Warenda Czura, Ph.D.Suffolk County Community CollegeEastern CampusPrimary Sources for figures and content:Marieb, E. N. Human Anatomy & Physiology 6th ed. San Francisco: Pearson BenjaminCummings, 2004.Martini, F. H. Fundamentals of Anatomy & Physiology 6th ed. San Francisco: PearsonBenjamin Cummings, 2004.Amy Warenda Czura, Ph.D.1SCCC BIO130 Chapter 14 Lecture SlidesBrain Structure1. Cerebrum-largest part of human brain-2 cerebral hemispheres covered in cerebral (neural) cortex-surface convoluted to increase surface area for neurons (~3ft2) -gyri = elevated ridges-sulci = depressions -fissures = big sulciThe Brain and Cranial NervesSpinal cord → reflex = immediate responseBrain → thinking = adaptable but slowerAmy Warenda Czura, Ph.D.2SCCC BIO130 Chapter 14 Lecture Slides-longitudinal fissure separates left and righthemispheres-base of fissure has corpus callosum: axons toconnect neurons of hemispheres-hemispheres divided into five lobes eachAmy Warenda Czura, Ph.D.3SCCC BIO130 Chapter 14 Lecture Slides-central sulcus divides frontal lobes fromparietal lobes-lateral sulcus divides frontal lobes fromtemporal lobes-parieto-occipital sulcus divides parietal lobesfrom occipital lobes-insula located at base of lateral sulcus beneathfrontal and temporal lobesAmy Warenda Czura, Ph.D.4SCCC BIO130 Chapter 14 Lecture Slides2. Cerebellum-second largest part-consists of right and left hemispheres connected by the vermis-covered in cerebellar cortex-folia instead of gyri-each hemisphere divided into anterior and posterior lobes by the primary fissureAmy Warenda Czura, Ph.D.5SCCC BIO130 Chapter 14 Lecture Slides3. Diencephalon -links cerebral hemispheres to brain stem -3 parts: epithalamus, thalamus,hypothalamus4. Brain stem -connects to spinal cord -consists of mesencephalon, pons, andmedulla oblongataAmy Warenda Czura, Ph.D.6SCCC BIO130 Chapter 14 Lecture Slides5. Ventricles -holes in brain that circulate CSF A. Lateral ventricles-in each cerebral hemisphere B. Third ventricle-in diencephalon C. Fourth ventricle-in between pons and cerebellum-connects to central canal of spinal cordProtection of the brain1. Cranial bones: form the skull -occipital, frontal, sphenoid, ethmoid,parietals, temporalsAmy Warenda Czura, Ph.D.7SCCC BIO130 Chapter 14 Lecture Slides2. Cranial meninges -hold brain in place -prevent contact with skull A. Dura mater -two layers -no epidural space: fused to periosteum -forms dural folds deep into fissures: 1. falx cerebri: between cerebralhemispheres in longitundinal fissure 2. tentorium cerebelli: between cerebrumand cerebellum 3. falx cerebelli: between cerebellarhemispheresAmy Warenda Czura, Ph.D.8SCCC BIO130 Chapter 14 Lecture SlidesB. Arachnoid 1. arachnoid membrane 2. arachnoid trabeculae: span subarachnoidspace which contains CSF C. Pia mater -adheres to brain via astrocytes -follows topology of gyri and sulci3. Cerebrospinal fluid-functions: a. cushion brainb. support brainc. diffusion medium-produced by choroid plexus (= ependymal cells plus capillaries in brain ventricles)Amy Warenda Czura, Ph.D.9SCCC BIO130 Chapter 14 Lecture Slides-volume of CSF in brain and cord turned overevery 8hrs-choroid plexus secretes ~500ml/day-CSF reabsorbed at arachnoid granulationsAmy Warenda Czura, Ph.D.10SCCC BIO130 Chapter 14 Lecture SlidesHydrocephalus = (infants) failure to reabsorbCSF, fluid expands cranium and crushes brainhttp://uuhsc.utah.edu/healthinfo/images/ei_0433.gifhttp://tier.cs.berkeley.edu/gallery/ghana05/IMGP1551_001http://www.diagnostico.com/Trejos/HydrocephalusIII.JPGhttp://www.telegraph.co.uk/news/graphics/2005/04/28/wviet28a.jpgAmy Warenda Czura, Ph.D.11SCCC BIO130 Chapter 14 Lecture Slides4. Blood-brain barrier-capillaries of CNS less permeable: -endothelial cells linked by tight junctions -astrocytes cover capillary surface-only lipid soluble compounds diffuse intoCNS, all others actively transported byastrocytes-inflammation (infection, cancer) can break down blood brain barrierAmy Warenda Czura, Ph.D.12SCCC BIO130 Chapter 14 Lecture SlidesBrain Anatomy:(on handout)Brainstem1. Medulla Oblongata (details on handout)2. Pons (details on handout)Amy Warenda Czura, Ph.D.13SCCC BIO130 Chapter 14 Lecture Slides3. Midbrain / Mesencephalon(details on handout)Diencephalon(details on handout)Amy Warenda Czura, Ph.D.14SCCC BIO130 Chapter 14 Lecture SlidesCerebellum(details on handout)Ataxia = loss of balance due to disruption incerebellum (e.g. alcohol)Limbic System-functional not anatomical separationAmy Warenda Czura, Ph.D.15SCCC BIO130 Chapter 14 Lecture Slides-located between cerebrum and diencephalon:parts of both-functions:-establishes emotional states and drives-links conscious functions of cerebrum to autonomic functions of brainstem-facilitates memory storage and retrievalSpecial regions1. amygdala: fight or flight, initiates fearresponse, links emotion with memory2. hippocampus: memory and learning3. cingulate gyrus: expressing emotions viagestures, & resolves mental conflictsAmy Warenda Czura, Ph.D.16SCCC BIO130 Chapter 14 Lecture SlidesCerebrum(details on handout)Amy Warenda Czura, Ph.D.17SCCC BIO130 Chapter 14 Lecture SlidesExamples of integrative centers:1. Wernicke’s area = general interpretive area -center of left hemisphere -gives meaning to auditory or visual cues2. Broca’s area = speech center -left hemisphere superior to lateral sulcus -coordinates motor controls for speech3. Prefrontal cortex -anterior frontal lobes -prediction, estimation, and related emotionsAmy Warenda Czura, Ph.D.18SCCC BIO130 Chapter 14 Lecture SlidesAssociation and integration areas all overcortex carry out all levels of thought butin general:-Left hemisphere: language, math, logic-Right hemisphere: interpret sensory info,generate emotions, spatial visualization-each hemispheres sends info to opposite side of body but each also has unique functions-hemispheres communicate for whole thought-if corpus callosum cut, hemispheres workindependently e.g.(used as treatment for seizures)Epileptic seizures = abnormal electrical activityin brain; causes loss of normal functionAnencephaly = brain fails to develop abovemesencephalon, fatalCerebrovascular Accident (CVA) = “stroke”,loss of blood supply to brain, neuron deathoccurs in minutes*Individual cranial nerves and theirinnervations will be