Post on 21-Jun-2020
CHAPTER 18The Brain and the Cranial Nerves
Copyright © 2007 by John Wiley & Sons, Inc.
Principles ofHuman Anatomy
Eleventh EditionGerard J. Tortora
&
Mark T. Nielsen
Major Brain AreasMajor Brain Areas
19_01b19_01b Cerebrospinal FluidCerebrospinal Fluid FunctionsFunctions
Mechanical protectionMechanical protection Chemical protectionChemical protection CirculationCirculation
Formed by:Formed by: EpendymalEpendymal cells of the Choroid Plexusescells of the Choroid Plexuses
Flow from the choroid plexuses to the Flow from the choroid plexuses to the arachnoidarachnoidvillavilla
CircumventricularCircumventricular organsorgans HypothalamusHypothalamus PitutaryPitutary Pineal gland (body)Pineal gland (body)
Brain VentriclesBrain Ventricles
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19_04c19_04c 19_04d_part119_04d_part1
Brain StemBrain Stem
Medulla oblongataMedulla oblongata Ascending sensory & descending motor tractsAscending sensory & descending motor tracts Cross over at Cross over at decussationdecussation of pyramidsof pyramids MedullaryMedullary rhythmicityrhythmicity area (basic breathing rhythm)area (basic breathing rhythm) Complex reflexive behaviorsComplex reflexive behaviors
PonsPons PneumotaxicPneumotaxic and and apneusticapneustic areas (breathing reg.)areas (breathing reg.) Reticular formation (RAS)Reticular formation (RAS)
Sleep & wake cyclesSleep & wake cycles
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CerebellumCerebellum
White matter White matter –– Arbor vitaeArbor vitae The tree of lifeThe tree of life
Coordinates complex motor sequencesCoordinates complex motor sequences
19_08abc19_08abc
19_08d19_08d HypothalamusHypothalamus
ANSANS Pituitary glandPituitary gland Emotional & behavioral patternsEmotional & behavioral patterns Eating and drinkingEating and drinking Body temperatureBody temperature Diurnal rhythmsDiurnal rhythms
HypothalamusHypothalamus CerebrumCerebrum Cerebral cortex Cerebral cortex –– rolls and foldsrolls and folds
Rolls Rolls -- GyriGyri Deep folds Deep folds –– fissures fissures
E.g. Longitudinal fissureE.g. Longitudinal fissure Shallow folds or grooves Shallow folds or grooves –– sulcisulci
E.g. Central E.g. Central sulcussulcus
LobesLobes Frontal, Parietal, Occipital, TemporalFrontal, Parietal, Occipital, Temporal
19_11ab19_11ab White matter in the cerebrumWhite matter in the cerebrum
MyelinatedMyelinated axon tracts that extend in 3 axon tracts that extend in 3 directionsdirections Association fibersAssociation fibers –– connect connect gyrigyri w/in a w/in a
hemispherehemisphere Commissural fibersCommissural fibers –– connect connect gyrigyri of one of one
hemisphere to the opposite hemisphere to the opposite gyrigyri in the other in the other hemispherehemisphere
Projection fibersProjection fibers –– ascending & descending ascending & descending tracts connecting the cerebrum with other tracts connecting the cerebrum with other brain parts and spinal cordbrain parts and spinal cord
White Matter TractsWhite Matter Tracts Functional areas of the cortexFunctional areas of the cortex
Sensory Sensory –– receive informationreceive information Motor Motor –– control of muscular control of muscular
movementsmovements Association Association –– complex integrative complex integrative
functionsfunctionsMemory, emotion, reason, personality Memory, emotion, reason, personality
intelligenceintelligence
Functional areas of the cortexFunctional areas of the cortex
Sensory areasSensory areas Primary Primary somatosensorysomatosensory cortexcortexPostPost--central central gyrusgyrus
Touch, Touch, proprioceptionproprioception, pain, temperature, pain, temperature
Entire body represented, but not equallyEntire body represented, but not equallyLips and fingers Lips and fingers –– larger area devotedlarger area devoted
Functional Areas of CortexFunctional Areas of Cortex
21_0521_05 Functional Areas of CortexFunctional Areas of Cortex
Primary Motor CortexPrimary Motor CortexPrePre--central central gyrusgyrusVoluntary contractions of motor Voluntary contractions of motor groupsgroups
Muscles represented, but not equallyMuscles represented, but not equally Large area for vocalization and handsLarge area for vocalization and hands
Functional Areas of CortexFunctional Areas of Cortex 21_0521_05
Functional Areas of CortexFunctional Areas of Cortex
Primary visual cortexPrimary visual cortex Medial surface of occipital lobeMedial surface of occipital lobe
Primary auditory area Primary auditory area Temporal lobeTemporal lobe
Auditory association areaAuditory association area WernickeWernicke’’ss area area –– usually in the left usually in the left
hemispherehemisphere Motor speech areaMotor speech area
BrocaBroca’’ss area area –– usually in the left hemisphereusually in the left hemisphere
Functional Areas of CortexFunctional Areas of Cortex
Brain LateralizationBrain Lateralization Split BrainsSplit Brains
See a star with the right eyeSee a star with the right eyeCan tell you they saw a starCan tell you they saw a star
See a star with the left eyeSee a star with the left eyeCannot tell you what they sawCannot tell you what they sawCan point to itCan point to itBut only with their left handBut only with their left hand
Cranial NervesCranial Nerves11Oh, Oh, 22Oh, Oh, 33Oh, Oh, 44To, To, 55Touch, Touch, 66And, And,
77Feel, Feel, 88Very, Very, 99Grotesque, Grotesque, 1010Visera, Visera, 1111AA1212Hhhhh!!Hhhhh!!
11Olfactory, Olfactory, 22Optic, Optic, 33Occulomotor, Occulomotor, 44Trochlear, Trochlear, 55Trigeminal, Trigeminal, 66Abducens, Abducens, 77Facial, Facial, 88Vestibulocochlear, Vestibulocochlear, 99Glossopharyngeal, Glossopharyngeal, 1010Vagus, Vagus, 1111Accessory, Accessory, 1212HypoglossalHypoglossal
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19_05b19_05b 19_05c19_05c
19_07a19_07a Learning Objectives
Discuss the importance of a choriodplexus
Describe a circumventricular organ and give examples
What are some of the functions of the following: medulla oblongata, pons, cerebellum, hypothalamus, decussation of pyramids
Learning Objectives
Discuss the components of the brain stem Discuss the components of the
diencephalon What is the arbor vitae Discuss the functional areas of the cortex Why are Broca’s and Wernicke’s areas
important? Discuss brain lateralization
Learning Objectives
Discuss association commissural and projection fibers in the cerebrum
Describe the corpus callosum Compare white vs. gray matter Discuss how a split brain individual reacts
to visual cues Memorize the cranial nerve names and
functions