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14. Homeostasis

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  1. 14.1 Homeostasis in Mammals

    1. 14.1.1Homeostasis definition and importance

      • Homeostasis definition and importance

    2. 14.1.2Homeostasis control principles

      • Principles: internal/external stimuli, receptors, coordination systems (nervous/endocrine), effectors (muscles/glands), negative feedback

    3. 14.1.3Urea production

      • Urea produced in liver from deamination of excess amino acids

    4. 14.1.4Kidney gross structure

      • Kidney structure: fibrous capsule, cortex, medulla, renal pelvis, ureter, branches of renal artery/vein

    5. 14.1.5Nephron structure

      • Nephron parts: glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct

    6. 14.1.6Urine formation

      • Urine formation: - Glomerular filtrate by ultrafiltration in Bowman's capsule - Selective reabsorption in proximal convoluted tubule

    7. 14.1.7Nephron structure and function

      • Relate Bowman's capsule and proximal convoluted tubule structure to function

    8. 14.1.8Osmoregulation with ADH

      • Osmoregulation: roles of hypothalamus, posterior pituitary gland, ADH, aquaporins, collecting ducts

    9. 14.1.9Glucagon cell signalling

      • Cell signalling example - glucagon control of blood glucose: - Hormone binding to receptor causes conformational change - G-protein activation stimulates adenylyl cyclase - Second messenger cAMP formation - Protein kinase A activation by cAMP initiates enzyme cascade - Signal amplification through enzyme cascade by phosphorylation - Cellular response: final enzyme activates glycogen breakdown

    10. 14.1.10Negative feedback control of blood glucose

      • Negative feedback control of blood glucose: - Insulin effects on muscle and liver cells - Glucagon effects on liver cells

    11. 14.1.11Glucose test strips and biosensors

      • Test strips and biosensors for glucose measurement: glucose oxidase and peroxidase enzymes

  2. 14.2 Homeostasis in Plants

    1. 14.2.1Stomata response to environmental changes

      • Stomata response to environmental changes: balance CO2 uptake by diffusion with minimising water loss

    2. 14.2.2Daily rhythms of stomatal opening and closing

      • Daily rhythms of stomatal opening and closing

    3. 14.2.3Guard cells

      • Guard cell structure and function in stomatal mechanism

    4. 14.2.4Abscisic acid and stomata

      • Abscisic acid role in stomatal closure during water stress: calcium ions as second messenger