1. U N I T 2 Sensitivity and COORDINATION. By Adrián Muñiz

2. Stimuli and responses A stimulusisanythingthataffectsany of thebody’sactivities. There are two types of stimuli: INTERNAL: they come from inside our bodies. EXTERNAL: these come from outside the body. Response: ItIsthebodyanswerto a stimulus. e.g. Weeatwhenwe are hungry. Stimulus Response

3. StimuliReceptors The body has different receptors to receive different types of stimuli. There are two types of receptors: Internal receptors. They receive the internal stimuli our bodies produce. They are all over the body. External receptors. They receive external stimuli. They are in the sensory organs. http://vimeo.com/7592583(Video)

4. Responses Thebodyrespondstoanystimulus. There are twobasictypes of responses: Muscular responses: These are movementsthemusclesmake in response to a stimulus. Glandular responses: These are whenglands produce varioussubstances in response to a stimulus.

5. THE SENSES (1) Sight:Theeyeisthebody’sorganforthesense of sight.Theeyeismade up of theeyeballand protectedbytheeyebrows,eyelids and eyelashes Hearing:Theearisthebody’sorganforthesense of hearing.Theear has threeparts: 1-The outerear2-The middleear3-The innerear Touch: Thebody’sorganforthesense oftouchistheskin.Theskinismade up of threelayers: 1-Epidermis 2-Dermis 3-Hypodermis

6. THE SENSES (2) Smell:Thebody’sorganforthesense of smellisthenose.Thereceptors of smell are in thepituitary, a structureinsidethenostrils.Theorganforthesense of smellisthenose. Taste: Thebody’sorganforthesense of tasteisthetongue.Thereceptors of taste are in thetaste buds.

7. THE NERVOUS SYSTEM AND HOW IT WORKS(1) Thenervoussystemreceives and interpretstheinformation of theinternal and externalreceptors,anditdevelops and transmits a response.Itismade up of nerves and nerve centres. Nervestransmitinformation. Theyare theperipheralnervoussystem. Thenerve centres interprettheinformation and develop responses. Theyformthecentral nervoussystem. The central nervoussystem: Ithas twoparts: Brain: Itisinsidetheskull.It has threemainparts:cerebrum,cerebellum and brainstem. Spinalcord:Itis a thickcordmade up of manyneuronsthatsgoesthroughtheinside of thespine.

8. THE NERVOUS SYSTEM AND HOW IT WORKS(2) TheperipheralnervoussystemItismade up of nerves: Sensorynerves.Theytransmitinformationfromthesensoryorgans and internalorganstothe central nervoussystem. Motor nerves.Theytransmit responses fromthe central nervoussystemtothemuscles and glands of ourbodies.

9. THE NERVOUS SYSTEM AND HOW IT WORKS(3) NeuronsNeurons are cellsthatbelongtothenervoussystem.Theyhave a star-likeshapemade up of threeparts :a cellbody,dendrites and axons.

10. THE NERVOUS SYSTEM AND HOW IT WORKS(4) VOLUNTARY MOVEMENTS Thisishowthenervoussystemreactsto a stimuluswithvoluntarymovements. 1-Sense nerves2-Brain 3-Motor nerves InvoluntarymovementsWithinvoluntarymovementsorreflexes,itisthespinalcord and notthebrainthatdevelops a response

11. Theend!!