1.0 Basic Brain Anatomy c(1)
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Transcript of 1.0 Basic Brain Anatomy c(1)
1.0$Basic$Brain$AnatomyStructure$&$Func6on
Carter$(2014)$pp$40=67Plus$DVD
Objectives Lecture 1.0• Learn basic structure of central and
peripheral nervous system
• Characteristics of brain - Size, neurons, glia
• Major lobes of brain
• Neural terminology
• Learn to use Carter DVD (responsible for all nerves and neural areas that are RED)
The Nervous SystemAnatomical and functional subdivisions• Central nervous system (CNS) - includes the
brain and spinal cord
• Peripheral nervous system (PNS) includes
• Consists of
• Autonomic system (ANS) - Autonomic nervous system shares nerves with CNS and PNS but functions automatically to control heart rate, breathing, temperature, blood pressure, etc
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•12 Pairs cranial nerves (except optic nerve) originate from brain•Relays
information
•
•31 pairs spinal nerves originate from the spinal cord•Afferent signals
•Efferent signals
•
Carter DVD:
Go To: The Nervous System: System Overview
(Responsible for all nerves and areas that light up in RED)
!Brain!Size!Weight!Head‣ *Weight!Brain‣ .
Size!Brain‣Approx.Consistency‣ Firm!JelloGender!differences!in!weight?‣
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Brain!Weight!&!Gender
‣ Brain!weight!increases!*!max!at!adolescence‣ Male!brain!consistently!heavier!than!female!over!all!ages‣ Percent!of!body!weight!*
Weight
% of total body weight
MaleFemale
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Brain Size, Sulci & Gyrus By Species (Elephant, Human, Dolphin, Wolf, Cat)
Is!Brain!Size!Related!to!Genius‣ Jonathan!SwiD!*!2000!gr‣ Pavlov!*!1500!gr‣ Einstein’s!brain!?!*!1230!gr‣ Had!very!wide!parietal!
area/lacked!sulcus!(STS)!Superior!temporal!sulcus!‣ Enhanced!
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Cerebral!Cortex!(Neocortex)
• Cortex!.!Gray!maEer!
• Outer!layer!*!thickness!2!*!5!mm!/!1/4!inch
• Responsible!for!higher!cogniWve!processes!*!percepWon,!aYenWon,!focus!and!concentraWon,!memory,!decision!making!and!problem!solving
• Motor!..
• Gyrus!&!Sulcus!
• Gyri!(pl)*!Bulges!of!parts!of!cortex
‣ Sulci!(pl)!*!Deep!folds!in!cortex
Gyrus!and!Sulcus
• Purpose:!Greatly!increases!the!surface!area!and!processing!capability!of!the!brain
• If!the!human!cortex!was!flaYened!out,!it!would!cover!an!area!of!
• approx.!?
Gyrus
Sulcus
Sulcus!&!Gyrus!(cont’d)• Central!sulcus!*!division!
between!
• Sylvian!Fissure!*!deep!sulcus!separates
• Superior!temporal!sulcus!(STS)!*!temporal!and!parietal!from!occipital
• associated!with!higher!levels!of
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Brain Is Composed of Neurons & Glia Cells
• Neurons - at birth highest number - approx 500 billion - undifferentiated
• Growth, development & life experiences reduce to “about 86 billion”
• Neurons (yellow) are replaced over our lifetime
• Myth of neuron death -
• Neurogenesis -
Neurons & Glia Cells• Glia cells - 10x number glia cells (860 billion glia)
• Glia (blue and red) means “glue” (Greek); supports neurons; provides nutrition, carries out housekeeping
• NEW - glia recently linked to higher intelligence and problem solving (human glia placed within
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Four Major Lobes of Cerebral CortexCortex is the thin outer
layerOnly 3-5 mm/ 1/4 inch thick
Major Lobes of Brain
Carter DVD: Go To
Whole Brain Anatomy
Major Functions of 4 Lobes• Occipital Lobe - in motor
learning/control - visual input often influences motor behaviour first
• processes
• Parietal lobe - computes
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Major Function of 4 Lobes
• Temporal lobe - center of
• Frontal lobe - higher thought center;
LeJ!and!Right!Hemispheres2"Hemispheres"Linked"by"corpus"callosum• 200"million$connec6ng$nerve$fibres$• Le7"hemisphere"controls$right$hand$and$
foot• Right"hemisphere$control$leK$hand• Le7"hemisphere$=$more$linear,$speech$
and$language,$
• Right"hemisphere$=$more$sensi6ve$to$sensory$input,$auditory$and$visual$awareness,
• Gender"difference$in$corpus$callosum=$more"connec=ons$in$women$(DVD$&$pp.$198)
• Lobotomy$=$severed$corpus$collosum$=$1950’s$treatment$for$epilepsy,$mental$illness
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LeD!and!Right!Hemispheres!of!Brain• Can$we$live$without$one$
hemisphere?$• Yes.$Surgical$removal$as$
child.$Led$a$normal$life.$• Child$could$speak$2$
languages$(p.$199$Carter)• What$makes$this$case$so$
interes6ng?• $
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Neural TerminologyLocation and Direction
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Terminology:Location
& Direction
Medial
Anterior
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The Brain’s Surface Features• often difficult to determine front
and back of brain - which view is most difficult to ID?•Clues: cerebellum/orientation of
temporal lobe/check for labels•Dorsal view • left and right hemisphere• separated by
•Ventral view: • cerebellum (small or little brain)
visible•
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The Brain’s Surface FeaturesLateral view: • Frontal, parietal, occipital, temporal lobes and cerebellum• Pre-motor and motor cortices are in the frontal lobe
Medial view: •Corpus callosum and
cingulate gyrusCingulate cortex or gyrus• above corpus callosum• critical in
Carter DVDGo to:
MRI Atlas MRI Terms for Location & Direction
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Tuesday, September 9, 2014