Your Nervous SystemYour Nervous System

Central Nervous SystemCentral Nervous System

EngageEngage

ExploreExplore

Clay BrainsClay Brains

ExplainExplainCNSCNS

Relays messagesRelays messagesProcesses informationProcesses informationAnalyzes informationAnalyzes information

Parts of CNSParts of CNS

1.1. TheThe Spinal Cord Spinal Cord

2.2. The The BrainBrain

ProtectionsProtections Skull and VertebraeSkull and Vertebrae 33 protective layers called protective layers called meningesmeninges1.1. Dura MaterDura Mater (outer layer): consists of connective tissues, (outer layer): consists of connective tissues,

blood vessels, and nerves.blood vessels, and nerves.2.2. Arachnoid LayerArachnoid Layer (middle layer): elastic and weblike (middle layer): elastic and weblike3.3. Pia MaterPia Mater (inner layer): contains nerves and blood (inner layer): contains nerves and blood

vessels.vessels.4.4. Cerebrospinal fluidCerebrospinal fluid

a clear watery liquida clear watery liquid separates the middle and inner layers separates the middle and inner layers Acts as shock absorberActs as shock absorber exchange of nutrients between blood and nervous systemexchange of nutrients between blood and nervous system

Pons

Pituitary gland

Hypothalamus

Cerebrum

Medulla oblongata Spinal cord

Cerebellum

Pineal gland

Thalamus

Section 35-3

The BrainThe Brain

The brain is the The brain is the controlcontrol centercenter of the of the bodybody

It is about It is about 2%2% of your of your body body weightweight and and uses uses 20%20% of your of your body’s body’s oxygenoxygen

Parts of the BrainParts of the Brain

Divided into Divided into threethree parts parts CerebrumCerebrum CerebellumCerebellum Brain StemBrain Stem

CerebrumCerebrum

1.1. LargestLargest part of the brain part of the brain – – Learning and Senses Learning and Senses

2 hemispheres-2 hemispheres- Right and Left Right and Left Connected by the Connected by the Corpus CallosumCorpus Callosum Right sideRight side controls- controls- left sideleft side Left side Left side controls – right side of bodycontrols – right side of body Four sections - Four sections - LOBESLOBES

1. 1. Frontal Frontal Lobe 2. Lobe 2. Parietal Parietal LobeLobe 3. 3. OccipitalOccipital Lobe 4. Lobe 4.TemporalTemporal Lobe Lobe

Gray Matter vs. White MatterGray Matter vs. White Matter

Gray MatterGray Matter – Absence of myelin in – Absence of myelin in masses of neurons accounts for the gray masses of neurons accounts for the gray matter of the brain – matter of the brain – Cerebral Cortex Cerebral Cortex

White MatterWhite Matter - Myelinated neurons gives - Myelinated neurons gives neurons a white appearance – inner layer neurons a white appearance – inner layer of cerebrumof cerebrum

CerebellumCerebellum

Second largestSecond largest located located belowbelow the the

cerebrum at back of cerebrum at back of skull skull

This part is This part is responsible for the responsible for the balancebalance and and musclemuscle coordinationcoordination

Brain StemBrain Stem

Connects the Connects the brain tobrain to spinal cordspinal cordThe The Two RegionsTwo Regions act as “switchboard” act as “switchboard”

Medulla Oblongata – Medulla Oblongata – Controls heart rate, Controls heart rate, breathing rate, and flow of blood through breathing rate, and flow of blood through the blood vessels.the blood vessels.

Pons – Pons – Relays signals between the Relays signals between the cerebrum and the cerebellumcerebrum and the cerebellum

Other Structures inside the BrainOther Structures inside the Brain

Thalamus Thalamus – receives messages from – receives messages from sensory receptors; relays information to sensory receptors; relays information to proper regions of cerebrumproper regions of cerebrum

Hypothalamus - Hypothalamus - Regulates hunger, thirst, Regulates hunger, thirst, fatigue, anger, etc… fatigue, anger, etc… Control of pituitary for endocrine functionControl of pituitary for endocrine function

Pons

Pituitary gland

Hypothalamus

Cerebrum

Medulla oblongata Spinal cord

Cerebellum

Pineal gland

Thalamus

Section 35-3

Spinal nerve

Central canalGray matter

White matter

Meninges

Section 35-3

Cross Section of the Spinal Cord

Spinal CordSpinal Cord

Link between brain and rest of body (PNS)Link between brain and rest of body (PNS)31 pairs of spinal nerves31 pairs of spinal nervesReflexes processed directly by spinal cordReflexes processed directly by spinal cordReflex Reflex – quick, automatic, unconscious – quick, automatic, unconscious

responsesresponsesResult of Result of reflex arcsreflex arcs – shortest nerve pathways – shortest nerve pathways

ElaborationElaboration

Nicotine in the Body and BrainNicotine in the Body and Brain

Drugs and the Nervous Drugs and the Nervous SystemSystem

Drug – any substance, other than food that Drug – any substance, other than food that changes the structure or function of the changes the structure or function of the bodybody

LegalLegal IllegalIllegal

Drugs That Affect the SynapseDrugs That Affect the Synapse

Used to increase alertness, relieve fatigue

Used to relieve anxiety, irritability, tension

Used to relieve pain

Stimulants

Depressants

Opiates

Amphetamines

BarbituratesTranquilizers

MorphineCodeine

Increase heart and respiratory rates; elevate blood pressure; dilate pupils; decrease appetite

Slow down the actions of the central nervous system; small amounts cause calmness and relaxation; larger amounts cause slurred speech and impaired judgement

Act as a depressant; cause drowsiness, restlessness, nausea

Section 35-5

Commonly Abused Drugs

Drug Type Medical Use Examples Effects on the body

1. Stimulants1. Stimulants IncreaseIncrease

Heart rateHeart rate Blood pressureBlood pressure BreathingBreathing Release of neurotransmitters at some synapses in the Release of neurotransmitters at some synapses in the

brain brain Deplete neurotransmitters and lead to: Deplete neurotransmitters and lead to:

Fatigue Fatigue Circulatory problemsCirculatory problems HallucinationsHallucinations DepressionDepression

2. Depressants2. Depressants

DecreaseDecrease Heart rateHeart rate Breathing rateBreathing rate Blood pressureBlood pressure Relax musclesRelax muscles Relieve tensionRelieve tension

Enhances release of neurotransmitters Enhances release of neurotransmitters that prevent nerves cells from firingthat prevent nerves cells from firing

Alcohol with depressants can lead to Alcohol with depressants can lead to death – depresses CNS to a point one death – depresses CNS to a point one stops breathingstops breathing

3. Opiates3. Opiates

Mimics endorphinsMimics endorphins EndorphinEndorphin – natural chemical in brain that helps – natural chemical in brain that helps

overcome pain overcome pain When person stops takingWhen person stops taking

Brain has adjusted to high levels of endorphins Brain has adjusted to high levels of endorphins Cannot produce enough natural endorphinsCannot produce enough natural endorphins Suffer uncontrollable pain and sicknessSuffer uncontrollable pain and sickness

4. Cocaine4. Cocaine

Sudden release of Sudden release of DopamineDopamine Powerful StimulantPowerful Stimulant Increases heart rate and blood pressureIncreases heart rate and blood pressure First time users can have heart attackFirst time users can have heart attack DopamineDopamine – neurotransmitter in brain that is – neurotransmitter in brain that is

released to give feeling of pleasure and released to give feeling of pleasure and satisfactionsatisfaction

5. Marijuana5. Marijuana Active ingredient (THC) tetrahydrocannabinolActive ingredient (THC) tetrahydrocannabinol More destructive to lungs than cigarettesMore destructive to lungs than cigarettes

5 marijuana cigs = 120 conventional cigs5 marijuana cigs = 120 conventional cigs

Results in:Results in: Lower WBC count by 40% - susceptible to infectionsLower WBC count by 40% - susceptible to infections Teens – Teens –

inhibits maturity inhibits maturity Retards normal brain growthRetards normal brain growth

Memory lossMemory loss Inability to concentrateInability to concentrate Fall short on memory as well as math and verbal skillsFall short on memory as well as math and verbal skills

Males – reduced testosterone levels and increases estrogen levelsMales – reduced testosterone levels and increases estrogen levels Females – Females –

disturbs menstrual cycledisturbs menstrual cycle DNA damage to eggsDNA damage to eggs

More Effects (FYI)More Effects (FYI) Impaired perception Impaired perception Loss of coordination Loss of coordination Increased risk of accidents Increased risk of accidents Impaired judgement Impaired judgement Loss of motivation Loss of motivation Diminished inhibitions Diminished inhibitions Increased heart rate Increased heart rate Anxiety, panic attacks, and paranoia Anxiety, panic attacks, and paranoia Hallucinations Hallucinations Damage to the respiratory, reproductive, and immune systems Damage to the respiratory, reproductive, and immune systems Increased risk of CANCERIncreased risk of CANCER Psychological dependencyPsychological dependency

6. Alcohol6. Alcohol DepressantDepressant Slows down CNSSlows down CNS

40% of 50,000 highway deaths are caused by 40% of 50,000 highway deaths are caused by drinking and drivingdrinking and driving

1/3 of homocides attributed to effects of alcohol1/3 of homocides attributed to effects of alcohol $150 billion dollars of U.S. economy alcohol abuse $150 billion dollars of U.S. economy alcohol abuse

treatmenttreatment Fetal Alcohol Syndrome (FAS)Fetal Alcohol Syndrome (FAS)

Drinking while pregnantDrinking while pregnant Heart defects, malformed faces, delayed growth, poor Heart defects, malformed faces, delayed growth, poor

motor developmentmotor development

Alcohol and DiseaseAlcohol and Disease

Long-term alcohol use or bouts of Long-term alcohol use or bouts of excessive consumptionexcessive consumptionDestroys liver cellsDestroys liver cellsCirrhosis of liver – formation of scar tissue Cirrhosis of liver – formation of scar tissue

that prevents blood flow through liverthat prevents blood flow through liver

Drug AbuseDrug Abuse

Intentional misuse of any drug for Intentional misuse of any drug for nonmedical purposesnonmedical purposes

AddictionAddiction – uncontrollable dependence – uncontrollable dependence on a drugon a drug

Only Way to Prevent Addiction Only Way to Prevent Addiction and Effects of Drugsand Effects of Drugs

NOT taking them to begin withNOT taking them to begin with