Co-ordination Electrical messenger Chemical messenger.

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Co-ordination Electrical messenger Chemical messenger

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Transcript of Co-ordination Electrical messenger Chemical messenger.

  • Co-ordination Electrical messenger

    Chemical messenger

  • Nervous System

  • Neuron

  • cytoplasmdendroncell membranenucleusnucleus of cell which makes the myelin sheathaxondirection of nerve impulses

  • Nerve fiber

  • Myelin SheathProtection of nerve fiberSpeed up impulse transfer

  • Rest PotentialMore + ion outside the neroneNa K pumpK channelBig - ions

  • Action potential

  • Action potential mechanismDepolarizationStimulus to thresholdNa channel openInside nerone turn +ve.RepolarizationPotential rise inside nerone to maxNa channel closeMore k channel open so hyperpolarisedRest potential established by na k pump.

  • Na openK openNa closeRefractory period

  • ending of axon secretes a chemical which diffuses into synapse and stimulates the next neurone to pass on the impulsethe chemical is unstable and will be destroyed later

  • Synapse

  • Synapse mechanismGo

  • SynapticCleftNeurotransmitter in vesicle release to cleft. It diffuse to another side and attach on surface receptor. Enzyme next to receptor break down. Transmitter

  • Brain

  • Reflex arc : sensory, association, motor neurones

  • Peripheral Nervous Systemconsist of cranial nerves and spinal nervesthese nerves leave CNS and run out to every part of the body

  • Spinal Cell

  • Endocrine SystemHormone conceptSteroid conceptEndocrine organs

  • Hormone conceptHormone is chemical messenger.It required a fitted receptor.Hormone attaching to receptor calls response.

  • Hormone concept 2Hormone required blood vessel to transport to whole body.

  • Water soluble hormoneWater soluble hormone only attach to membrane receptor.

  • Fat soluble hormone (steroid)Steroid can penetrate cell membrane and bind to internal receptor.

  • Example of steroids

  • Feedback mechanismNegative feedback reduce hormone production when effect of hormone expressed

  • Endocrine and ExocrineBlood vesselSecretary duct

  • Endocrine organs

  • Adrenal glandAdrenalin

  • Photo of adrenal gland

  • Pancreas Islet of langerhans

  • Thyroid gland

  • Pituitary gland

  • Control of endocrine systemHormone control hormone Nerve control hormone

  • Anterior and Posterior Pituitary gland

  • Photo of pituitary gland