Nervous system

Nervous system1Teaching Points1. The functions of the nervous system is to receive the information happening in both inside and out of the body, respond to the information and lastly maintain homeostasis.2. The structure of a neuron includes the cell body with a nucleus, extensions called dendrites and an axon.3. The central nervous system is in control of the center part of the body and consists of the brain and the spinal cord.4. The peripheral nervous system controls nerves that connect out of the central nervous system and involves both voluntary and involuntary actions5. The sense in our body includes vision, hearing and balance, smell and taste, and touchBell Work Function Of The Nervous System

Receiving InformationMakes you aware of what is happening around youChecks what is going on inside your body (ex: glucose rate in the blood)

Responding To InformationStimulus -> change or signal in the environment that can make an organism reactResponse -> what your body does to react to the stimulusHeart rate -> controlled by involuntary actions of the nervous system

6Maintaining HomeostasisThe nervous system maintains homeostasis by directing the body to respond appropriately to the information it receivesEx: You get hungry when your body needs food

The Structure Of A Neuron

A neuron is a nerve cell.Structure Of A NeuronLarge body cell with a nucleusDendrites carry impulses towards the cell bodyThe axon carries impulses away from the cell bodyBundle of nerve fiber = nerve

Kinds Of NeuronsSensory neuron -> picks up stimulus from the environment and converts it into nerve impulsesInterneuron -> carries nerve impulses from one neuron to anotherMotor neuron -> sends impulse to muscle or gland and react in response

How A Nerve Impulse Travels

Synapse -> the junction where one neuron transfers an impulse to another structureThere is a gap between axon tips and dendritesCentral Nervous SystemIncludes the brain and a spinal cordBrain -> controls most functions of the bodySpinal cord -> links brain to most of the nerves in the outer body system

The Brain and Spinal CordHas three layers of connective tissueBetween the innermost layer and the middle layer, it is filled with fluids to protect the brain

The BrainThree main regions that receive and process information 1 cerebrum2 cerebellum3 brain stem

CerebrumInterpret inputs from the senses, control movement, and carries out complex mental process (ex: learning/remembering)Largest part of the brain

Left HalfRight HalfControls right skeleton musclesControls left skeleton muscles

Mathematical skillsCreativityLogical thinkingArtistic ability

15Cerebellum and Brain StemCerebellum -> coordinates actions of your muscles and helps you keep your balanceBrain Stem -> involuntary actions that occur

Spinal CordThe link between your brain and the rest of the bodyVertebral column -> surrounds the spinal cord to protect them

17Peripheral Nervous SystemNetwork of nerves that branch out from the central nervous system Controls both voluntary and involuntary actions43 pairs of nerves12 pairs in the brain31 spinal nerves

How Spinal Nerves FunctionImpulses travel on a spinal nerve both to and from the nervous system

How Each FunctionSpinal neurons -> carry both sensory and motor neuronsSensory neurons (Impulse :body -> central nervous system)Motor neurons (Impulse: central nervous system -> body)

20The Somatic and Automatic Nerves of the peripheral nervous system can be divided into two groupsSomatic Nervous System -> controls voluntary actionsAutomatic Nervous System -> controls involuntary actions

ReflexesReflex -> automatic response that occurs rapidly without conscious controlSome reflex actions only interact with the spinal cordImpulses make you feel pain for protection

The SensesVision Hearing/BalanceSmell/TasteTouch

VisionStimulus of light converts into impulses to let you seeCornea, pupil, iris, lens, and retina are the parts of your eyes

Hearing/BalanceSounds is produced by vibrationsOuter ear: gathers sound wavesMiddle ear: eardrum that vibrates soundInner ear: has auditory nerves Semi-circular canals control your balance

Smell/TasteChemicals that make you smell and taste50 basic odors5 main tastes sweet, sour, salty, bitter, umamiNose and mouth work together

TouchSkin is the largest sense organ that contain touch receptor everywhereTouch, pressure, temperature change, and pain are dermis feels

27Video

Activity Right now we all will do an activity in which you all will become part of the nervous systemLets All Go Out On The Roof