GCSE›Edexcel GCSE Biology›Mind mapsHomeostasisEdexcel GCSE Biology: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsWhy constant?Thermoregulation keeps enzymes at optimumOsmoregulation stabilises blood water contentStops cells bursting or shrinkingTemperatureHypothalamus monitors temperatureCold: shivering and vasoconstrictionHot: vasodilation and sweatingVasoconstriction narrows vessels, less heat lossBlood glucoseInsulin lowers glucose, glucose to glycogenGlucagon raises glucoseType 1: no insulin, treat with injectionsType 2: insulin resistance, diet and exerciseBMI=mass (kg)height (m)2\text{BMI} = \frac{\text{mass (kg)}}{\text{height (m)}^2}BMI=height (m)2mass (kg)Homeostasiskeeping conditions steadyKidneysFiltration at glomerulus and Bowman's capsuleSelective reabsorption of all glucoseUrea comes from liver deaminationProtein and blood cells stay in the bloodADHADH raises collecting duct permeabilityMore water reabsorbed, concentrated urineLess ADH gives dilute urineDialysis or transplant treats kidney failureExam tipsEnzymes denature, they do not dievasoconstriction in cold, vasodilation when hotMore ADH means more reabsorption