Central Nervous System (CNS) –Central Nervous System (CNS) – –Brain and spinal cord Peripheral Nervous System (PNS) –Peripheral Nervous System (PNS) –

• Central Nervous Central Nervous SystemSystem (CNS) – (CNS) – – Brain and spinal cordBrain and spinal cord

• Peripheral Nervous Peripheral Nervous SystemSystem (PNS) – (PNS) – – Made up of nerves that Made up of nerves that

attach to CNSattach to CNS

Peripheral Nervous Peripheral Nervous SystemSystem

S ke le ta l

(S om atic)

S ym pathe tic P arasym pathe tic

A utonom ic

Periphera l Nervous S ystem

Functional Subdivisions Functional Subdivisions of the PNSof the PNS• PNS contains 2 PNS contains 2

functional functional subdivisionssubdivisions– Sensory Sensory

(afferent) (afferent) nervesnerves conduct conduct sensory impulses sensory impulses to CNS from to CNS from receptors in receptors in organs and tissuesorgans and tissues

– Motor (efferent) Motor (efferent) nervesnerves conduct conduct impulses away impulses away from CNS to from CNS to muscle effectors muscle effectors and glandsand glands

Subdivisions of Motor Subdivisions of Motor Division (PNS)Division (PNS)

• Somatic Nervous Somatic Nervous System System (SNS) –(SNS) –– Controls voluntary and Controls voluntary and

involuntary skeletal involuntary skeletal muscle contractionsmuscle contractions

– Involuntary skeletal Involuntary skeletal contraction – contraction – reflexreflex

– Single neuron systemSingle neuron system

• Autonomic Nervous Autonomic Nervous System System (ANS) –(ANS) –– Controls activity of Controls activity of

smooth and cardiac smooth and cardiac musclesmuscles

– 2 neuron system2 neuron system• 11stst: from CNS to ganglion: from CNS to ganglion• 22ndnd: from ganglion to : from ganglion to

effectoreffector

SubdivisioSubdivisions of ANSns of ANS

• Sympathetic Sympathetic divisiondivision – – – Fight or flightFight or flight

• ParasympatheParasympathetic divisiontic division – –– Regulates Regulates

resting functions resting functions • Ex., digesting Ex., digesting

foodfood

SympatheticSympathetic• “ “ Fight or flight” Fight or flight”

responseresponse• Release Release

adrenaline and adrenaline and noradrenaline noradrenaline

• Increases heart Increases heart rate and blood rate and blood pressurepressure

• Increases blood Increases blood flow to skeletal flow to skeletal musclesmuscles

• Inhibits digestive Inhibits digestive functionsfunctions

CENTRAL NERVOUS SYSTEMBrain

Spinalcord

Dilates pupil

Stimulates salivation

Relaxes bronchi

Accelerates heartbeat

Inhibits activity

Stimulates glucose

Secretion of adrenaline,nonadrenaline

Relaxes bladder

Stimulates ejaculationin male

Sympatheticganglia

Salivaryglands

Lungs

Heart

Stomach

Pancreas

Liver

Adrenalgland

Kidney

Inhibits

ParasympatheticParasympathetic• “ “ Rest and Rest and

digest ” digest ” systemsystem

• Calms body Calms body to conserve to conserve and maintain and maintain energyenergy

• Lowers Lowers heartbeat, heartbeat, breathing breathing rate, blood rate, blood pressurepressure

CENTRAL NERVOUS SYSTEMBrain

Spinalcord

Stimulates salivation

Constricts bronchi

Slows heartbeat

Stimulates activity

Contracts bladder

Stimulates erectionof sex organs

Stimulates gallbladder

Gallbladder

Contracts pupil

Summary of Summary of ANSANS differencesdifferencesAutonomic nervous system controls physiological arousal

Sympatheticdivision (arousing)

Parasympatheticdivision (calming)

Pupils dilate EYES Pupils contract

Decreases SALIVATION Increases

Perspires SKIN Dries

Increases RESPIRATION Decreases

Accelerates HEART Slows

Inhibits DIGESTION Activates

Secrete stresshormones

ADRENALGLANDS

Decrease secretionof stress hormones

• Made up primarily Made up primarily of 2 types of cells:of 2 types of cells:– NeuronsNeurons– Supporting cellsSupporting cells

•CNS - CNS - neuroglianeuroglia (glial cells) (glial cells)

– Astrocytes, Astrocytes, microglia, microglia, ependymal cells, ependymal cells, oligodendrocytesoligodendrocytes

•PNS – satellite PNS – satellite cells, Schwann cells, Schwann cellscells

NeuronsNeurons• Made up of a Made up of a cell cell bodiesbodies, , dendritesdendrites, and , and axonsaxons

• Cell bodyCell body (or (or somasoma))– Contains large nucleus Contains large nucleus

and and Nissl bodiesNissl bodies (Rough (Rough E.R.), primary site of E.R.), primary site of protein synthesisprotein synthesis

– Most located within CNS Most located within CNS where they are protected where they are protected by hard bones of skull by hard bones of skull and vertebral column and vertebral column

– Collection in CNS is called Collection in CNS is called ““nucleinuclei” whereas in PNS ” whereas in PNS they are called “they are called “gangliaganglia””

More on More on Neuron Neuron StructureStructure

• DendritesDendrites – Short, highly Short, highly

branched signal branched signal receptive regions of receptive regions of nerve cellnerve cell

– Convey incoming Convey incoming message toward the message toward the cell bodiescell bodies

• Each nerve cell Each nerve cell (neuron) has only (neuron) has only one one axonaxon– Impulse generating Impulse generating

and conducting and conducting region of neuronregion of neuron

Myelin Sheath of the Myelin Sheath of the AxonAxon

• Whitish, fatty protein Whitish, fatty protein layerlayer

• Serves to protect Serves to protect and electrically and electrically insulate axoninsulate axon

• Increases the speed Increases the speed of transmission of of transmission of nerve impulses (up nerve impulses (up to 150 times faster)to 150 times faster)

• Only associated with Only associated with axons, not dendritesaxons, not dendrites

REVIEW:REVIEW:Functional ClassificationFunctional Classification• Neurons are grouped according to the Neurons are grouped according to the

direction in which the nerve impulse direction in which the nerve impulse travels relative to the CNStravels relative to the CNS

• Based on this there are Based on this there are sensorysensory, , motormotor, and , and association neuronsassociation neurons– SensorySensory – transmit impulses from skin or – transmit impulses from skin or

other organs toward CNSother organs toward CNS– MotorMotor – carry impulses away from CNS to – carry impulses away from CNS to

effector organseffector organs– Association (interneurons)Association (interneurons) – lie between – lie between

motor and sensory neuronsmotor and sensory neurons

Neuron Video

neurilemma

Neuroglia (CNS)Neuroglia (CNS)

• CNS has 4 different types of CNS has 4 different types of supporting cellssupporting cells ((neuroglianeuroglia))– Abundant and diverse Abundant and diverse – Limited knowledge of each function due to Limited knowledge of each function due to

difficulty in isolating individual cellsdifficulty in isolating individual cells• Ependymal cellsEpendymal cells

– Line central cavities of brain and spinal cordLine central cavities of brain and spinal cord– Beating of cilia help to circulate the Beating of cilia help to circulate the

cerebrospinal fluidcerebrospinal fluid (CSF) (CSF)– CSF: protection of brain and transport of vital CSF: protection of brain and transport of vital

nutrients and wastenutrients and waste• AstrocytesAstrocytes

– Attach neurons to capillaries, linking them to Attach neurons to capillaries, linking them to nutrient supplynutrient supply

Neuroglia CONT….Neuroglia CONT….•OligodendrocytesOligodendrocytes

– Branches wrap around neuron fibers, Branches wrap around neuron fibers, forming an insulating covering called a forming an insulating covering called a myelin sheathmyelin sheath

•MicrogliaMicroglia– Monitor health of nerve cellsMonitor health of nerve cells– If foreign invader detected or cell If foreign invader detected or cell

damaged, many microglia head to the damaged, many microglia head to the area, transform into macrophages, and area, transform into macrophages, and protect the CNS by phagocytizing the protect the CNS by phagocytizing the microorganisms or neuronal debrismicroorganisms or neuronal debris

Neuroglia (CNS)Neuroglia (CNS)

Label your Synapses Label your Synapses DiagramDiagram

• HINTS FOR YOU:HINTS FOR YOU:

= Sodium ions= Sodium ions

= Potassium ions= Potassium ions

= Calcium ions= Calcium ions

= synaptic vesicles w/ = synaptic vesicles w/ neurotransmittersneurotransmitters

= chemical gated channels= chemical gated channels

Use pages 392 and 406 in the AP book

Action potentialAction potential

• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html

ANIMATION OF CHEMICAL ANIMATION OF CHEMICAL SYNAPSESSYNAPSES

• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__chemical_synapse__quiz_1_.html

Animation of ENTIRE SYNAPTIC PROCESS with ACTION POTENTIAL

Sodium/Potassium PumpSodium/Potassium Pump

• http://highered.mcgraw-hill.com/http://highered.mcgraw-hill.com/sites/0072495855/student_view0/sites/0072495855/student_view0/chapter2/chapter2/animation__how_the_sodium_potasanimation__how_the_sodium_potassium_pump_works.htmlsium_pump_works.html

Action Potential GraphAction Potential Graph

•Know what happens at each Know what happens at each part of the graph with part of the graph with relationship to the pre-relationship to the pre-synaptic and post-synaptic synaptic and post-synaptic activities.activities.

•Look at the HANDOUT with Look at the HANDOUT with the graph!!the graph!!

• Also known as “Nerve Impulses”Also known as “Nerve Impulses”• Self-regenerating wave of Self-regenerating wave of electroelectrochemicalchemical

activity that allows neurons to carry a signal activity that allows neurons to carry a signal over a distance (“game of telephone”)over a distance (“game of telephone”)

• Pulse-like waves of voltage that Pulse-like waves of voltage that travel along several types of cell travel along several types of cell membranes membranes

• http://outreach.mcb.harvard.edu/animations/ http://outreach.mcb.harvard.edu/animations/ actionpotential.swfactionpotential.swf

• Initiation/Resting StageInitiation/Resting Stage::– Some Some K+K+ channels are channels are openopen: K+ diffusion : K+ diffusion

occurring occurring – Initiated by stimulus above a certain intensity Initiated by stimulus above a certain intensity

or or thresholdthreshold ((~~-70mV – -70mV – resting potentialresting potential))– Could be a pin prick, light, heat, sound or an Could be a pin prick, light, heat, sound or an

electrical disturbance in another part of the electrical disturbance in another part of the neuron (“telephone call”)neuron (“telephone call”)

– Electrical signal rises Electrical signal rises from changes in from changes in permeability of the permeability of the neuron’s axon membranes neuron’s axon membranes to specific ions ( to specific ions (Na+Na+ && K+K+))

Depolarization (Rising Phase)Depolarization (Rising Phase)• K+ ChannelK+ Channel gates are closedgates are closed• Stimulus causes gate in the Stimulus causes gate in the Na+ ChannelNa+ Channel to open to open• High concentration of Na+ outside, Na+ diffuses High concentration of Na+ outside, Na+ diffuses

intointo neuron neuron• Electrical potential changes to ~ +40 mV.Electrical potential changes to ~ +40 mV.

Repolarization (Falling Phase)Repolarization (Falling Phase)• Depolarization causes Depolarization causes K+ ChannelK+ Channel gate to gate to

immediately open & immediately open & Na+ ChannelNa+ Channel close close• K+ diffuses K+ diffuses out ofout of neuron neuron• Reestablishment of initial electrical potential of ~-Reestablishment of initial electrical potential of ~-

60 mV.60 mV.

Refractory Period (Recovery Phase)Refractory Period (Recovery Phase)• Na+ & K+ Channels cannot be opened by a stimulusNa+ & K+ Channels cannot be opened by a stimulus• Na+/K+ PumpNa+/K+ Pump actively (ATP) pumps actively (ATP) pumps Na+ outNa+ out of & of &

K+ intoK+ into neuron neuron• Reestablishment of ion distribution of resting neuronReestablishment of ion distribution of resting neuron• This AP acts as stimulus to neighboring proteins & This AP acts as stimulus to neighboring proteins &

initiates AP in another part of neuroninitiates AP in another part of neuron• Wave of APs travel from Wave of APs travel from

dendrites to axon terminalsdendrites to axon terminals• At axon terminal, At axon terminal, electrical electrical

impulseimpulse is converted to a is converted to a chemical signal (neurotransmitter)chemical signal (neurotransmitter)

http://bcs.whfreeman.com/thelifewire/content/chp44/4402002.html

Per. 2 start, Fri

Per. 4, WU go over handout

• Getting the message across Getting the message across (the synapse)? (the synapse)?– http://www.mind.ilstu.edu/curriculum/neurons_intro/neurons_intro.phphttp://www.mind.ilstu.edu/curriculum/neurons_intro/neurons_intro.php

– At axon terminal, chemical At axon terminal, chemical signal (NT) crosses synapse signal (NT) crosses synapse between adjacent neurons between adjacent neurons

• Starts AP on this neuronStarts AP on this neuron

– This activates This activates CaCa2+2+ channel channel to open to open• CaCa2+2+ diffuses diffuses intointo neuron neuron• Causes NT vesicles to move to end & fuse with cell Causes NT vesicles to move to end & fuse with cell

membranemembrane• Through Through exocytosisexocytosis, NTs are released into synapse, NTs are released into synapse

– NTs diffuse across synapse & bind to NT receptors on NTs diffuse across synapse & bind to NT receptors on another neuronanother neuron

• Causes Causes Na+ channelsNa+ channels to open & to open & AP is initiatedAP is initiated in next in next neuronneuron

• Information from one Information from one neuron flows to another neuron flows to another neuron across a neuron across a synapsesynapse……– a small gap separating a small gap separating

neurons that consists of: neurons that consists of: – a a presynaptic endingpresynaptic ending

that contains that contains neurotransmitters, neurotransmitters, mitochondria & other mitochondria & other organelles,organelles,

– a a postsynaptic endingpostsynaptic ending that contains receptor that contains receptor sites for neurotransmitters sites for neurotransmitters &&

– a a synaptic cleftsynaptic cleft or space or space between the presynaptic between the presynaptic & postsynaptic endings.& postsynaptic endings.

Let’s Review…Let’s Review…How do neurons communicate?How do neurons communicate?

• What is What is another name for the nerve impulseanother name for the nerve impulse that that travels from the axon hillock through the axon to the travels from the axon hillock through the axon to the axon terminal?axon terminal?

• What are the What are the 4 main phases4 main phases of an Action Potential? of an Action Potential?

• What happens in the What happens in the Rising PhaseRising Phase? ?

• Falling PhaseFalling Phase??

• Recovery PhaseRecovery Phase??

• Resting PotentialResting Potential??

• What What ionion entering the neuron entering the neuron instigates the movement of synaptic instigates the movement of synaptic vesicles to the cell membrane? vesicles to the cell membrane?

• What do the What do the vesicles releasevesicles release into into the synapse? the synapse?

• What happensWhat happens after the NTs are after the NTs are released into the synapse?released into the synapse?

Central Nervous SystemCentral Nervous System

•Brain and Brain and Spinal CordSpinal Cord

SpinalCord

Brain

• Average adult male’s brain weighs Average adult male’s brain weighs approximately 1.6 kg (~3.5 lbs)approximately 1.6 kg (~3.5 lbs)

• Average female’s: 1.42kgAverage female’s: 1.42kg• According to body weight, though…According to body weight, though…

they are relatively equal in sizethey are relatively equal in size

• Left & Right sides are Left & Right sides are separateseparate

• Corpus Callosum : major Corpus Callosum : major pathway between pathway between hemisphereshemispheres

• Some functions are Some functions are ‘lateralized’‘lateralized’– Language, numbers on leftLanguage, numbers on left– Color and music on rightColor and music on right

• Lateralization is never 100%Lateralization is never 100%

Brain has 2 HemispheresBrain has 2 Hemispheres

LeftHemisphere

Corpus CallosumRight

Hemisphere

Corpus CallosumCorpus Callosum• Major ( but not only) Major ( but not only)

pathway between sidespathway between sides• Connects comparable Connects comparable

structures on each sidestructures on each side• Permits data received on Permits data received on

one side to be processed one side to be processed in both hemispheresin both hemispheres

• Aids motor coordination Aids motor coordination of left and right side of left and right side

Corpus Callosum

Medial surface of right hemisphere

Contralateral Motor Contralateral Motor ControlControl

• Movements controlled Movements controlled by motor areaby motor area

• Right hemisphere Right hemisphere controls left side of controls left side of bodybody

• Left hemisphere Left hemisphere controls right sidecontrols right side

• Motor nerves cross Motor nerves cross sides in spinal cordsides in spinal cord

Somatosensory CortexMotor Cortex

Each hemisphere is Each hemisphere is divided into 4 lobes divided into 4 lobes

Frontal

Parietal

Occipital

Temporal

Cerebellum

• Cover and Cover and protect CNSprotect CNS

• Protect blood Protect blood vessels and vessels and enclose enclose venous venous sinusessinuses

• Contain Contain cerebrospinal cerebrospinal fluidfluid

• Form Form divisions divisions within the within the skullskull

Cerebral Cerebral White MatterWhite Matter

• Deep to the Deep to the gray gray matter matter of of cortex cortex

• Aids Aids communication communication between between cerebral cerebral areas and areas and between cerebral between cerebral cortex cortex and lower and lower CNS CNS

• Spinal cord has just the Spinal cord has just the opposite type of matteropposite type of matter

http://www.brainexplorer.org/brain-images/white_matter.jpg

FrontalLobe

Frontal LobeFrontal Lobe• Contains primary Contains primary

motor cortexmotor cortex

MotorCortexMotorCortexBroca’s

Area

MotorCortex

WorkingMemory

• No direct sensory No direct sensory inputinput

• Important planning Important planning and sequencing and sequencing areasareas

Broca’s area for Broca’s area for speechspeech

• Prefrontal area for Prefrontal area for working memoryworking memory

Occipital LobeOccipital Lobe

• Input from Optic Input from Optic nervenerve

• Contains primary Contains primary visual cortexvisual cortex– most is on surface most is on surface

inside central fissureinside central fissure

• Outputs to parietal Outputs to parietal and temporal lobesand temporal lobes

OccipitalLobe

VisualLobe

Temporal LobeTemporal Lobe• Inputs are auditory, Inputs are auditory,

visual patternsvisual patterns– speech recognitionspeech recognition– face recognitionface recognition– word recognitionword recognition– memory formationmemory formation

• Outputs to limbic Outputs to limbic System, basal System, basal Ganglia, and Ganglia, and brainstembrainstem

Contains primary auditory cortex

TemporalLobe

TemporalLobe

AuditoryCortex

ParietalLobe

SomatosensoryCortex

Parietal LobeParietal Lobe• Inputs from Inputs from

multiple sensesmultiple senses borders visual & auditory cortex

Outputs to Frontal lobe

hand-eye coordination

eye movements

attention

Regions & Regions & OrganizatioOrganizationn

• Cerebral Cerebral HemispheresHemispheres – –– Has outer cortex Has outer cortex

of gray matter of gray matter (neural bodies)(neural bodies)

• Diencephalon –Diencephalon –– Thalamus, Thalamus,

hypothalamus, hypothalamus, and epithalamusand epithalamus

• Brain StemBrain Stem – – – Midbrain, pons, Midbrain, pons,

medullamedulla• CerebellumCerebellum – –

– Has outer cortex Has outer cortex of gray matterof gray matter

Label the Label the worksheet on the worksheet on the brain!!brain!!•I will place the worksheet I will place the worksheet

under the under the document camera for document camera for you to view!!you to view!!

Cerebral HemispheresCerebral Hemispheres

• Approx. 83% of Approx. 83% of total brain masstotal brain mass

• Covered with Covered with elevations called elevations called gyrigyri and shallow and shallow grooves called grooves called sulcisulci

• Deeper grooves, Deeper grooves, called called fissuresfissures, , separate major separate major regions of the regions of the brainbrain

Cerebral CortexCerebral Cortex• It is the It is the gray mattergray matter of the cerebrum of the cerebrum• Enables us to perceive, communicate, Enables us to perceive, communicate,

remember, understand, appreciate, and remember, understand, appreciate, and initiate voluntary movementinitiate voluntary movement– It enables conscious behaviorIt enables conscious behavior

• Contains 3 functional areas:Contains 3 functional areas:– MotorMotor – control voluntary motor functions – control voluntary motor functions– SensorySensory – provide conscious awareness of – provide conscious awareness of

sensationsensation– AssociationAssociation – integrate diverse – integrate diverse

information for purposeful actioninformation for purposeful action

The Brain The Brain StemStem

• Includes:Includes:– MidbrainMidbrain– PonsPons– Medulla oblongataMedulla oblongata

• Structurally different Structurally different from brain because it from brain because it has deep has deep gray mattergray matter surrounded by surrounded by white matter (similar to spinal cord) white matter (similar to spinal cord)

• Coordinates head and eye movement when we Coordinates head and eye movement when we visually follow a moving object or see something out visually follow a moving object or see something out of corner of eyeof corner of eye

• Coordinates head reflex movement to unexpected Coordinates head reflex movement to unexpected auditory stimulusauditory stimulus

The DiencephalonThe Diencephalon• Surrounded by Surrounded by

the cerebral the cerebral hemisphereshemispheres

• Consists of 3 Consists of 3 bilaterally bilaterally symmetric symmetric structures:structures:– ThalamusThalamus– HypothalamusHypothalamus– EpithalamusEpithalamus

http://www.web-books.com/eLibrary/Medicine/Physiology/Nervous/diencephalon.jpg

The ThalamusThe Thalamus

•Egg-shaped Egg-shaped •Makes up 80% of Makes up 80% of

diencephalondiencephalon•Within the Within the

thalamus a thalamus a sorting-out and sorting-out and information information “editing” process “editing” process occursoccurs

The HypothalamusThe Hypothalamus• Caps the top of the brain stemCaps the top of the brain stem• Main visceral control center of the bodyMain visceral control center of the body• Vitally important to the homeostasis of the bodyVitally important to the homeostasis of the body• A few of its functions:A few of its functions:

– Regulates involuntary nervous system activities (blood Regulates involuntary nervous system activities (blood pressure, motility of digestive tract)pressure, motility of digestive tract)

– Perceives pleasure, fear, rage and sex drive (emotions)Perceives pleasure, fear, rage and sex drive (emotions)– Regulates body temp. by initiating Regulates body temp. by initiating – Regulates feelings of hunger and fullnessRegulates feelings of hunger and fullness– Regulates water balance and thirstRegulates water balance and thirst– Regulates sleep cycle in response to daylight-darkness Regulates sleep cycle in response to daylight-darkness

cues received by our eyescues received by our eyes– Controls endocrine system functioning – hormonal Controls endocrine system functioning – hormonal

balancebalance

EpithalamusEpithalamus

• Most dorsal portion of Most dorsal portion of the diencephalonthe diencephalon

• Forms roof of 3Forms roof of 3rdrd ventricleventricle

• Aids with sleep-wake Aids with sleep-wake cycle regulation cycle regulation ((pineal glandpineal gland))

• Helps with CSF Helps with CSF productionproduction

PonsPons• Helps to Helps to

maintain maintain normal normal rhythm of rhythm of breathingbreathing

• ““medulla”medulla”• Most inferior part Most inferior part

of the brain stemof the brain stem• Adjusts the force Adjusts the force

and rate of heart and rate of heart beat and depth of beat and depth of breathingbreathing

• Regulates Regulates vomiting, vomiting, hiccupping, hiccupping, swallowing, swallowing, coughing and coughing and sneezingsneezing

MedullaOblongata

The The CerebellumCerebellum

• Coordinate skeletal Coordinate skeletal muscle contractions muscle contractions needed for the needed for the smooth, coordinated smooth, coordinated movements of our movements of our daily lives daily lives – Ex., driving, Ex., driving,

typing, walkingtyping, walking• Cerebellar activity Cerebellar activity

occurs occurs subconsciouslysubconsciously

Cerebrospinal FluidCerebrospinal Fluid• Functions:Functions:

– Forms cushion for brain and other CNS organsForms cushion for brain and other CNS organs– Gives buoyancy to brain (which reduces weight by Gives buoyancy to brain (which reduces weight by

97%) to prevent brain from crushing under own 97%) to prevent brain from crushing under own weightweight

– Also helps blood in providing brain with nourishmentAlso helps blood in providing brain with nourishment

• Fun Fact:Fun Fact:– Average adult brain contains 150 ml and is replaced Average adult brain contains 150 ml and is replaced

every 3-4 hoursevery 3-4 hours

• Application:Application:– If CSF becomes obstructed, can cause condition If CSF becomes obstructed, can cause condition

called called hydrocephalushydrocephalus • Enlargement of the head in babies and brain damage in Enlargement of the head in babies and brain damage in

adultsadults

Looks Can Be DeceivingvWhat are these kinds of pictures called?

vWhat do these do to neuron communication within our Nervous System?

The The Dancing Dancing GirlGirl

• Look at the Look at the Dancer…Dancer…– Which way is she Which way is she

turning?turning?• ClockwiseClockwise? ? • Counter-clockwiseCounter-clockwise??

– Now stare at her Now stare at her bottom foot & squint bottom foot & squint your eyes…your eyes…• Does she start turning Does she start turning

the the other directionother direction??

Get lost in Get lost in the circlesthe circles• What happens What happens

when you focus when you focus on the on the center of center of a circlea circle??

Anatomy WARM-UPAnatomy WARM-UP• Read the article about Phineas Gage Read the article about Phineas Gage

then answer the following questions: then answer the following questions:

• What was Phineas’ occupation?What was Phineas’ occupation?• Why is the Phineas Gage story Why is the Phineas Gage story

so popular among medical so popular among medical science?science?

• Was there a change in Was there a change in Gage after the accident?Gage after the accident?

• Where can you go and view Where can you go and view Gage’s skull? Gage’s skull?

33rdrd qtr; week 5; day 2 qtr; week 5; day 2

• On a separate paper, write your On a separate paper, write your thoughts about this picture…thoughts about this picture…

• Your reactionsYour reactions• What do you think caused this What do you think caused this

situation?situation?– Based on what you know,Based on what you know,

• what kind of what kind of repercussionsrepercussions would would this accident have on the nervous this accident have on the nervous system?system?

– Now read the following story of Now read the following story of Phineas Gages’ tragic accident…Phineas Gages’ tragic accident…

– Write about your reactions to the Write about your reactions to the accidentaccident

• What What surprisedsurprised you about any info you about any info learned?learned?

• What kinds of things does the pre-What kinds of things does the pre-frontal cortex (lobe)frontal cortex (lobe) regulate? regulate?

VisionVision• PhotoreceptorsPhotoreceptors

are the visual are the visual receptor cellsreceptor cells

• Adult eye Adult eye averages 1 inch in averages 1 inch in diameterdiameter

• Accessory Accessory structures of the structures of the eye protect the eye protect the eye or aid in its eye or aid in its functioningfunctioning

Accessory StructuresAccessory Structures

• EyebrowsEyebrows• EyelidsEyelids• ConjunctivaConjunctiva• Lacrimal Lacrimal

apparatusapparatus• Extrinsic Eye Extrinsic Eye

musclesmuscles

Lacrimal ApparatusLacrimal Apparatus• Consists of the Consists of the lacrimal lacrimal

glandgland and and lacrimal lacrimal ductsducts

• Lacrimal gland releases Lacrimal gland releases fluid that contains mucus, fluid that contains mucus, antibodies, and lysozyme antibodies, and lysozyme (a bacteria-destroying (a bacteria-destroying enzyme)enzyme)

• Lacrimal gland is located Lacrimal gland is located superior and lateral to the superior and lateral to the eyeeye– It releases fluid, which is It releases fluid, which is

spread over eye by blinking, spread over eye by blinking, and drains via the medial and drains via the medial lacrimal canalslacrimal canals

PAGE 555 in AP book

Eyebrows and EyelidsEyebrows and Eyelids• EyebrowsEyebrows overlie the overlie the

supraorbial margins of the skullsupraorbial margins of the skull• They shade the eyes from They shade the eyes from

sunlight and prevent sunlight and prevent perspiration from entering the perspiration from entering the eyeseyes

• EyelidsEyelids cover the eye when cover the eye when the orbicularis oculi contractthe orbicularis oculi contract

• This occurs (blinking) every This occurs (blinking) every three to seven seconds to three to seven seconds to prevent desiccation of the eyesprevent desiccation of the eyes–EyelashesEyelashes (palpabrae)

are richly innervated, are richly innervated, so anything that so anything that touches them, including touches them, including a puff of air, triggers a puff of air, triggers reflex blinkingreflex blinking

Structure of the EyeballStructure of the Eyeball• Made up of three layers called tunics: fibrous (1), vascular (2) and Made up of three layers called tunics: fibrous (1), vascular (2) and

sensory (3)sensory (3)• Fibrous tunic is the outermost coat of the eyeFibrous tunic is the outermost coat of the eye• It is divided into two major regions: the cornea and the scleraIt is divided into two major regions: the cornea and the sclera• The sclera (tough connective tissue) is the “white of the eye” and The sclera (tough connective tissue) is the “white of the eye” and

functions to protect and shape the eyeballfunctions to protect and shape the eyeball• Also serves as sturdy anchoring point for Also serves as sturdy anchoring point for

extrinsic eye musculature extrinsic eye musculature

• PLEASE LABEL your PLEASE LABEL your wksht with color coding of wksht with color coding of your 3 tunics your 3 tunics

3

Iris Iris ((Vascular Vascular TunicTunic))

• Though it seems to appear Though it seems to appear in many colors (Iris means in many colors (Iris means rainbow), it actually only rainbow), it actually only contains brown pigmentcontains brown pigment

• When an iris contains a lot When an iris contains a lot of pigment, the eyes appear of pigment, the eyes appear brown or blackbrown or black

• If the amount of pigment is If the amount of pigment is small, the short small, the short wavelengths of light are wavelengths of light are scattered from the scattered from the unpigmented parts of the unpigmented parts of the iris, and eyes appear blue, iris, and eyes appear blue, green, or graygreen, or gray

• Why, then, do newborn Why, then, do newborn babies often appear to have babies often appear to have gray or blue eyes?gray or blue eyes?

The Sensory TunicThe Sensory Tunic• Contains the Contains the lens lens (hard (hard

disc) which allows an image disc) which allows an image that is upside down and that is upside down and backwards.backwards.

• This is the deepest layer This is the deepest layer and also has pigmented and also has pigmented cells that absorb lightcells that absorb light

• Also stores Vitamin A, Also stores Vitamin A, which is needed by the which is needed by the Photoreceptor cellsPhotoreceptor cells

• The retina contains millions The retina contains millions of photoreceptors known as of photoreceptors known as cones and rodscones and rods

Lens

CHECK YOUR LABELS!!!

ConjunctivaConjunctiva• A transparent mucous A transparent mucous

membrane that lines the membrane that lines the eyelids and reflects over the eyelids and reflects over the surface of the eyeballsurface of the eyeball

• It functions to lubricate the It functions to lubricate the eye and to prevent invasion eye and to prevent invasion to the posterior portion of to the posterior portion of the eyethe eye

• Conjunctivitis is an Conjunctivitis is an inflammation of the inflammation of the conjunctiva; Pinkeye is a conjunctiva; Pinkeye is a type of conjunctivitis caused type of conjunctivitis caused by bacteria or virusby bacteria or virus

More on the EyeMore on the Eye

• Cornea is lined with pain Cornea is lined with pain fibers (which is why contacts fibers (which is why contacts can be so tough to can be so tough to adjust to)adjust to)

• When cornea is touched, When cornea is touched, reflex blinking and increased reflex blinking and increased lacrimal fluid secretion occurlacrimal fluid secretion occur

• Since cornea has no blood supply it is the only Since cornea has no blood supply it is the only tissue that can be transplanted with very little tissue that can be transplanted with very little fear of rejection (does not have contact with fear of rejection (does not have contact with immune system)immune system)

Internal Internal ChambersChambers

• Filled with Filled with aqueous humoraqueous humor which is produced in the which is produced in the posterior chamber and posterior chamber and drains from the anterior drains from the anterior chamberchamber

• If this drainage is blocked, If this drainage is blocked, pressure within the eye may pressure within the eye may increase and cause increase and cause compression of the retina compression of the retina and optic nerve-a condition and optic nerve-a condition called called glaucomaglaucoma

• Exam to diagnose is simple…Exam to diagnose is simple…a puff of air at the sclera will a puff of air at the sclera will produce a measurable produce a measurable amount of deformationamount of deformation

Colorblind TestsColorblind Tests

• http://www.toledo-bend.com/http://www.toledo-bend.com/colorblind/Ishihara.htmlcolorblind/Ishihara.html

• http://colorvisiontesting.com/http://colorvisiontesting.com/onlineonline%20test.htm#demonstration%20test.htm#demonstration%20card%20card

ENDOCRINE SYSTEMENDOCRINE SYSTEM

•Responsible for sending Responsible for sending messages to target organs messages to target organs by secreting hormonesby secreting hormones

•Moves slower than the Moves slower than the Nervous systemNervous system

•

ENDOCRINE SYSTEMENDOCRINE SYSTEM• Please label all Please label all

of the glands of the glands on your wksht on your wksht and explain and explain what hormone what hormone is secreted is secreted from each of from each of them.them.

• Use pages 591-692Use pages 591-692 in the Anatomy in the Anatomy book!book!

Yes, you will need to identify what the hormone does for the body…MAKE IT BRIEF!!

THE ENDTHE END

The EarThe Ear

• Divided into three Divided into three major regions:major regions:

• Inner earInner ear• Middle earMiddle ear• Outer earOuter ear

•

LABEL YOUR WORKSHEET Page 573 in AP book

Outer EarOuter Ear• AuricleAuricle = the ear = the ear• made up of the made up of the helixhelix

(rigid portion) and(rigid portion) and lobulelobule (no cartilage) (no cartilage)

• directs sound waves directs sound waves into into auditory canalauditory canal

• canal is short (2.5 cm) canal is short (2.5 cm) and curved and and curved and extends to the extends to the tympanic membranetympanic membrane

• Canal is lined with Canal is lined with hairs, sebaceous hairs, sebaceous glands, and aprocrine glands, and aprocrine sweat glands called sweat glands called ceruminous glandsceruminous glands

Middle EarMiddle Ear• Small, air-filled Small, air-filled

cavity within the cavity within the petrous portion of petrous portion of temporal bonetemporal bone

• Eustachian tubeEustachian tube links middle ear to links middle ear to superiormost part of superiormost part of the throatthe throat– Normally this is Normally this is

closed, but yawning closed, but yawning and swallowing opens and swallowing opens this tube briefly to this tube briefly to equalize pressureequalize pressure

• Contains the three smallest bones Contains the three smallest bones in the body: the in the body: the ossiclesossicles

• Malleus (hammer)Malleus (hammer) – secured to – secured to the tympanic membranethe tympanic membrane

• Incus (anvil)- Incus (anvil)- connects other connects other bonesbones

• Stapes (stirrup)Stapes (stirrup) – connects to the – connects to the inner ear (via the oval window)inner ear (via the oval window)

• Tensor tympaniTensor tympani muscle attaches muscle attaches the auditory tube. The the auditory tube. The stapediusstapedius muscle runs from the wall of the muscle runs from the wall of the middle ear cavity and inserts into middle ear cavity and inserts into the stapesthe stapes

• These two muscles work together These two muscles work together to prevent damage to the inner ear to prevent damage to the inner ear under extremely loud conditionsunder extremely loud conditions

Inner EarInner Ear• Located deep Located deep

within the within the temporal bone temporal bone and posterior to and posterior to the eye socketthe eye socket

• Made up of the Made up of the vestibule, vestibule, cochlea, and cochlea, and semicircular semicircular canalscanals

VestibuleVestibule• Central egg-shaped Central egg-shaped

cavity that medially cavity that medially borders the middle earborders the middle ear

• Has oval window in its Has oval window in its lateral walllateral wall

• Contains perilymph Contains perilymph (similar to CSF)(similar to CSF)

• Houses equilibrium Houses equilibrium Sensors called Sensors called maculae that respond maculae that respond to the pull of gravity to the pull of gravity and report changes of and report changes of head positionhead position

Semicircular CanalsSemicircular Canals

• Made up of an Made up of an anterior, anterior, posterior, and posterior, and lateral canallateral canal

• Also have Also have receptors to help receptors to help with equilibriumwith equilibrium

CochleaCochlea• About half the size of About half the size of

a peaa pea• Contains three hollow Contains three hollow

cavities: Scala cavities: Scala vestibuli(terminates at vestibuli(terminates at oval window), cochlear oval window), cochlear duct, scala tympani duct, scala tympani (terminates at round (terminates at round window)window)

• Cochlear duct contains Cochlear duct contains spiral organ of Corti, spiral organ of Corti, which is the receptor which is the receptor organ for hearingorgan for hearing

HearingHearing

• Sounds set up vibrations in air that beat Sounds set up vibrations in air that beat against the ear drumagainst the ear drum

• This pushes the ossicles that press fluid This pushes the ossicles that press fluid in the inner ear against membranesin the inner ear against membranes

• This pressure on the membranes pulls This pressure on the membranes pulls on tiny hair cells that stimulate nearby on tiny hair cells that stimulate nearby neurons that give rise to impulses that neurons that give rise to impulses that travels to the brain, where they are travels to the brain, where they are interpretedinterpreted

Hair Cells in the Hair Cells in the Spiral Organ of Spiral Organ of CortiCorti

• Lining the organ of Lining the organ of Corti you find Corti you find roughly 16,000 roughly 16,000 hearing receptor hearing receptor cells called cochlear cells called cochlear hair cells sandwiched hair cells sandwiched between basilar between basilar membrane and membrane and tectorial membranetectorial membrane

DeafnessDeafness• Two types: conduction or sensorineuralTwo types: conduction or sensorineural• Conduction deafness – occurs when something Conduction deafness – occurs when something

interferes with conduction of sound vibrations interferes with conduction of sound vibrations to the fluids of the innner earto the fluids of the innner ear

• Sensorineural deafness – results from damage Sensorineural deafness – results from damage to neural structures at any point in the hearing to neural structures at any point in the hearing pathwaypathway– This typically result from the gradual loss of the This typically result from the gradual loss of the

hearing receptor cells:hearing receptor cells:• Throughout lifeThroughout life• Single explosively loud noiseSingle explosively loud noise• Prolonged exposure to high-intensity sounds, which cause Prolonged exposure to high-intensity sounds, which cause

these cells to stiffen these cells to stiffen (IPODs)(IPODs)