Coordination and response
Nervous control
- Nervous systemCNS: brain, spinal cordPNS: nerves outsideCoordination and regulation
- Neurones carry impulsesSensoryRelayMotor
- Reflex arcReceptorSensory, relay, motor neuronesEffector: muscle or gland
- Reflex actionAutomaticRapidProtects body
- Synapse: junction between neuronesSupplementVesiclesSynaptic gapReceptor proteinsOne direction only
Sense organs
- Sense organs: receptor cellsLightSoundTouchTemperature, chemicals
- Parts of the eyeCornea refractsIris controls lightLens focusesRetina, optic nerve
- Pupil reflexBright: smaller pupilDim: larger pupil
- Iris muscles antagonisticSupplementCircular narrows pupilRadial widens pupil
- AccommodationSupplementNear: thick lensDistant: thin lensCiliary muscles and ligaments
- Rods, cones and foveaSupplementRods: night visionCones: colourFovea: sharpest vision
Hormones
- Hormone definitionChemical substanceMade by a glandCarried in bloodTarget organs
- Endocrine glandsAdrenal: adrenalinePancreas: insulinTestes: testosteroneOvaries: oestrogen
- Nervous vs hormonalSpeedDuration of effect
- Adrenaline: fight or flightBreathing rate upHeart rate upPupils wider
- Adrenaline and metabolismSupplementBlood glucose upHeart rate up
Homeostasis
- Constant internal environmentBody temperatureBlood glucose
- Negative feedbackSupplementSet pointChange detectedChange reversed
- Insulin lowers blood glucoseMade by pancreas
- Glucagon and the liverSupplementGlucagon from pancreasGlucose to glycogenGlycogen to glucose
- Type 1 diabetesSupplementInsulin injectionsMonitor glucoseDiet
- Skin structuresSupplementHairs and erector musclesSweat glandsReceptors and neuronesFatty tissue
- Temperature controlSupplementSweatingShiveringVasodilationVasoconstriction
Tropic responses
- GravitropismShoots: awayRoots: towards
- PhototropismShoots: towards lightRoots: away from light
- Investigating tropismsOne variableControl setDark for gravity
- AuxinSupplementMade in shoot tipDiffusesUnequal distributionCell elongation
- Chemical control of growthSupplementLightGravity