Your Nervous SystemYour Nervous System

Peripheral Nervous SystemPeripheral Nervous System

Explain

which consists of

is divided into

that make up

which is divided into

Section 35-3

The Nervous System

Sensory nerves

Motor nerves

Autonomic nervous system

Somatic nervous system

Central nervous system

Peripheral nervous system

Sympathetic nervous system

Parasympathetic nervous system

PNSPNS

NERVES that connect the central NERVES that connect the central nervous system to the rest of the bodynervous system to the rest of the body

1.1. Motor Division – impulses from CNS to Motor Division – impulses from CNS to muscles or glandsmuscles or glands

Two Parts:Two Parts: Somatic Nervous SystemSomatic Nervous System Autonomic Nervous SystemAutonomic Nervous System

2.2. Sensory Division – transmits impulses Sensory Division – transmits impulses from sense organs to CNSfrom sense organs to CNS

Motor DivisionMotor DivisionPNSPNS

Somatic Nervous SystemSomatic Nervous System

Controls voluntary movement of the Controls voluntary movement of the skeletal musclesskeletal muscles

Autonomic Nervous SystemAutonomic Nervous System

Controls involuntary actionsControls involuntary actions Subdivided into two system that have Subdivided into two system that have

opposite effects on the same organs:opposite effects on the same organs:1.1. ParasympatheticParasympathetic – decreases heart rate – decreases heart rate

Controls internal organs during normal activityControls internal organs during normal activity

2.2. SympatheticSympathetic – increases heart rate – increases heart rate Controls internal organs during high stress activityControls internal organs during high stress activity

Sensory DivisionSensory DivisionPNSPNS

1. Pain Receptors1. Pain Receptors

Throughout body; except brainThroughout body; except brainRespond to chemical released by Respond to chemical released by

damaged cellsdamaged cells Important to recognizeImportant to recognize

DangerDanger InjuryInjuryDiseaseDisease

2. Thermoreceptors2. Thermoreceptors

In skin, body core, hypothalamusIn skin, body core, hypothalamusDetect variations in body temperatureDetect variations in body temperature

3. Mechanoreceptors3. Mechanoreceptors

Skin, skeletal muscle, and inner earsSkin, skeletal muscle, and inner earsSensitive to Sensitive to

TouchTouchPressurePressureStretching of musclesStretching of musclesSoundSoundmotionmotion

4. Chemoreceptors4. Chemoreceptors

Nose and TongueNose and TongueChemical in external environmentChemical in external environment

Choroid

Retina

Blood vessels

Optic nerve

Fovea

Vitreous humor

Sclera

Ligaments

Iris

Pupil

Cornea

Aqueous humor

Lens

Muscle

Section 35-4

Figure 35-14 The Eye

5. Photoreceptors5. Photoreceptors

EyesEyesSensitive to LightSensitive to Light

DO NOT WRITE NEXT INFO – IT IS ON DO NOT WRITE NEXT INFO – IT IS ON YOUR SHEETYOUR SHEET

VisionVision CorneaCornea

Helps focus lightHelps focus light Filled with Filled with aqueous humoraqueous humor

IrisIris Back of corneaBack of cornea Colored part of eyeColored part of eye

PupilPupil Tiny muscles regulate the sizeTiny muscles regulate the size Regulates amount of lightRegulates amount of light

LensLens Small muscles change its shape to focus on object near and Small muscles change its shape to focus on object near and

far awayfar away Behind lens eye filled with Behind lens eye filled with vitreous humorvitreous humor

RetinaRetina Has photoreceptorsHas photoreceptors No photoreceptors where optic nerve passes through the No photoreceptors where optic nerve passes through the

back of the eye; back of the eye; blind spotblind spot Two typesTwo types

1.1. Rods – black and whiteRods – black and white2.2. Cones – colorCones – color

Pathway for Vision ReceptionPathway for Vision Reception

LightLight corneacornea iris and pupiliris and pupil lenslens Retina to photoreceptorsRetina to photoreceptors

RodsRods Cones – FoveaCones – Fovea

Optic NerveOptic Nerve BrainBrain

Auditory canal

Tympanum Round window Eustachian tube

Bone

Cochlea

Cochlear nerve

Semicircular canals

Oval window

StirrupAnvilHammer

Section 35-4

Figure 35-15 The Ear

Hearing and BalanceHearing and Balance

EarEarTwo FunctionsTwo Functions

HearingHearingDetecting Positional change to movementDetecting Positional change to movement

HearingHearing Sound – air vibrationsSound – air vibrations Auditory canalAuditory canal – funnels air to – funnels air to tympanum tympanum (ear drum)(ear drum) TymapnumTymapnum – vibrates – vibrates Hammer, Anvil, StirrupHammer, Anvil, Stirrup- vibrate and transmit vibrations - vibrate and transmit vibrations

to to oval windowoval window CochleaCochlea – filled with fluid and vibrations create pressure – filled with fluid and vibrations create pressure

waves in the inner earwaves in the inner ear Tiny hairs respond to waves and send messages to Tiny hairs respond to waves and send messages to

brain via the brain via the cochlear nervecochlear nerve

BalanceBalance

Semicircular CanalsSemicircular Canals3 canals that form half circles3 canals that form half circlesFilled with fluid and hairs that detect motion of Filled with fluid and hairs that detect motion of

head in relation to gravityhead in relation to gravity

Auditory canal

Tympanum Round window Eustachian tube

Bone

Cochlea

Cochlear nerve

Semicircular canals

Oval window

StirrupAnvilHammer

Section 35-4

Figure 35-15 The Ear

Smell and TasteSmell and Taste

Chemoreceptors pick up chemical Chemoreceptors pick up chemical reception in nose and mouthreception in nose and mouth

Smell – Smell – olfactory bulbolfactory bulbTaste – Taste – taste budstaste buds

SaltySaltyBitterBitterSourSourSweetSweet

Cerebral cortex

Nasal cavity

Taste bud

Smell sensory area

Tastesensory area

Thalamus

Olfactory(smell) bulb

Olfactorynerve

Smell receptor

Taste pore

Taste receptor

Sensorynerve fibers

Section 35-4

The Senses of Smell and Taste

Touch and Related SensesTouch and Related Senses

Largest sense organ?Largest sense organ? SKINSKIN

Sensory ReceptorsSensory Receptors TemperatureTemperature TouchTouch PainPain

Greatest density of touch receptorsGreatest density of touch receptors FingersFingers ToesToes FaceFace

Concept Map

which consists of

is divided into

that make up

which is divided into

Section 35-3

The Nervous System

Sensory nerves

Motor nerves

Autonomic nervous system

Somatic nervous system

Central nervous system

Peripheral nervous system

Sympathetic nervous system

Parasympathetic nervous system