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