5 3. Brain Stem Attaches to the spinal cord Parts of the brain stem MidbrainPonsMedulla oblongata
6 4. Cerebrum Cerebral Hemispheres (Cerebrum) The surface is made of ridges (gyri) and grooves (sulci)A gyri is an elevated ridge of cerebral tissue.Inward folds of cerebral tissue arecalled fissures or sulci.
7 White matter—fiber tracts deep to the gray matter Layers of the cerebrumGray matter—outer layer in the cerebral cortex composed mostly of neuron cell bodiesWhite matter—fiber tracts deep to the gray matterCorpus callosum connects hemispheresBasal nuclei—islands of gray matter buried within the white matterGray matter is composed of cell bodiesof neurons.White matter is composed of fiber tracts.Nuclei deep within the cerebral white matter are collectively called basal nuclei (ganglia).
8 4. TERMSA bundle or fibers that provides for communication between different parts of the CNS is called a process. Like corpus callosumA bundle of fibers that carries impulses between the periphery and CNS areas is called a nerve.
10 6. Brain StructuresMedulla oblongata- most important autonomic center of the brain & contains autonomic centers regulating heart rate, respiration, and other visceral activities.Corpora quadrigemina- located in the midbrain; contains reflex centers for vison and hearing.Cerebellum- coordinates complex muscular movements.Corpus callosum- large fiber tract connecting cerebral hemispheres.Pituitary gland & pineal body- part of the endocrine systemCerebral aqueduct- canal that connects the third and fourth ventriclesThalamus- contains the intermediate mass
11 Protection of the Central Nervous System Scalp and skinSkull and vertebral columnMeningesCerebrospinal fluid (CSF)Blood-brain barrier
12 Trauma to base of brainBase of brain houses the brain stem, which houses most of the vital autonomic centers. Controls heart rate, respiration, blood pressure.
13 Protection of the Central Nervous System Figure 7.17a
14 8. MeningesDura mater-outermost layer; tough fibrous connective tissue,falx cerebri, a subdivision of dura mater that separates the right and left cerebral hemispheresA dural fold that attaches the cerebrum to the crista galli of the skullArachnoid layerMiddle layerWeb-like; delicate with cottony fibersPia mater-innermost vascular layer covering the brain; follows every convolutionClings to the surface of the brain
16 8. Cerebrospinal Fluid (CSF) Similar to blood plasma compositionchoroid plexus- structure that forms the cerebrospinal fluidForms a watery cushion to protect the brainCirculated in arachnoid space, ventricles, and central canal of the spinal cordArachnoid villi drains cerebrospinal fluid into venous blood in the dural venous sinuses
17 10. Ventricles and Location of the Cerebrospinal Fluid Choroid plexusFigure 7.18a–b
18 10. Ventricles and Location of the Cerebrospinal Fluid 7. Dural sinuses1. Lateral ventricles188.8.131.52.4.Lateral ventricle third ventricle cerebral aqueduct of midbrain fourth ventricle- central canal subarachnoid space arachnoid villi dural sinusesFigure 7.18c
19 Blood-Brain BarrierIncludes the least permeable capillaries of the bodyExcludes many potentially harmful substancesUseless as a barrier against some substancesFats and fat soluble moleculesRespiratory gasesAlcoholNicotineAnesthesia
20 Traumatic Brain Injuries ConcussionSlight brain injuryNo permanent brain damageContusionNervous tissue destruction occursNervous tissue does not regenerateCerebral edemaSwelling from the inflammatory responseMay compress and kill brain tissue
21 Cerebrovascular Accident (CVA) Commonly called a strokeThe result of a ruptured blood vessel supplying a region of the brainBrain tissue supplied with oxygen from that blood source diesLoss of some functions or death may result
22 Alzheimer’s Disease Progressive degenerative brain disease Mostly seen in the elderly, but may begin in middle ageStructural changes in the brain include abnormal protein deposits and twisted fibers within neuronsVictims experience memory loss, irritability, confusion, and ultimately, hallucinations and death
24 PNS: Cranial Nerves I Olfactory nerve—sensory for smell II Optic nerve—sensory for visionIII Oculomotor nerve—motor fibers to eye musclesIV Trochlear—motor fiber to eye muscles
25 PNS: Cranial NervesV Trigeminal nerve—sensory for the face; motor fibers to chewing musclesVI Abducens nerve—motor fibers to eye musclesVII Facial nerve—sensory for taste; motor fibers to the faceVIII Vestibulocochlear nerve—sensory for balance and hearing
26 PNS: Cranial NervesIX Glossopharyngeal nerve—sensory for taste; motor fibers to the pharynxX Vagus nerves—sensory and motor fibers for pharynx, larynx, and visceraXI Accessory nerve—motor fibers to neck and upper backXII Hypoglossal nerve—motor fibers to tongue