The Nervous System Responses L.O: To know how the body senses and responds to the outside environment

Can you name the senses and list example of them e.g. candle – sight and smell

Sense Organs Each organ has receptors sensitive to particular kinds of stimulus… Each organ has receptors sensitive to particular kinds of stimulus… SkinTongueNoseEyesEars  What stimuli do these sense organs detect? Your nervous system carries electrical impulses very quickly 1 to 120 metres per second.

What different stimuli are there and what organs detect them? Light (from the torch) Light (from the torch) Sound (whistle) Sound (whistle) Change in position (move on a chair) Change in position (move on a chair) Chemicals (smell and taste) Chemicals (smell and taste) Touch (the feel of an object) Touch (the feel of an object) Pressure (object pressing against the skin) Pressure (object pressing against the skin) Pain (being pinched) Pain (being pinched) Temperature (ice cube and warm water) Temperature (ice cube and warm water)

Test the different objects and try to work out what the stimulus and receptor is for each. Note: glands are also effectors which respond to chemicals e.g. to secrete saliva, or release hormones into the blood

Conscious Response Example Stimulus  Receptor  Coordinator  Effector  Response What are the stimulus, receptor, coordinator, effector and response in the following example? What are the stimulus, receptor, coordinator, effector and response in the following example? Oh No!

Conscious Response Example  Stimulus – shark swims close; receptor – eyes detect shark; coordinator – brain determines what to do; effector – muscles respond; response – individual swims quickly!

Conscious Responses Stimulus  Receptor  Coordinator  Effector  Response Stimulus – a change in the environment Stimulus – a change in the environment Receptor – a specialised cell which detects the stimulus Receptor – a specialised cell which detects the stimulus Coordinator – part of the body which coordinates a response Coordinator – part of the body which coordinates a response Effector – part of the body which produces a response Effector – part of the body which produces a response Response – the change in the body Response – the change in the body

Information passes from the Receptors (which transform the energy to electrical) along neurons to the brain which coordinates the response TO DO: Put this sequence of events into your flow diagram Sensory neurone Relay neurone Motor neurone Stimulus and receptor Co-ordinator (CNS) Effector

What are the differences between the motor and sensory neurones? Motor Neurone: Takes messages from the brain or spinal cord to the muscles and organs Sensory Neurone: Takes messages from receptors to the brain or spinal cord

Neurones join at synapses Chemicals are secreted between the gaps Chemicals are secreted between the gaps Synapses slow down impulses, but one neurone can synapse several Synapses slow down impulses, but one neurone can synapse several A relay neurone has synapses with a sensory and motor neurone and also those to the brain A relay neurone has synapses with a sensory and motor neurone and also those to the brain In the above case information from the brain can over ride a reflex In the above case information from the brain can over ride a reflex

Can you use your other senses if one stops working? possible-real-life-bat-man.html possible-real-life-bat-man.html

The brain is important in responding to different stimuli It tries to co-ordinate all the stimuli and sometimes gets confused! It tries to co-ordinate all the stimuli and sometimes gets confused! The stroop effect The stroop effect

Say the colour not the word YELLOWBLUE ORANGE ORANGE BLACK BLACK RED RED GREEN GREEN ORANGE ORANGE GREEN GREEN BLACK BLACK BLUE BLUE

Left – Right Brain conflict Right brain tries to say the word Right brain tries to say the word Left brain tries to read the word Left brain tries to read the word