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hormonal communication (diabetes (type 1 (usually starts in childhood or…

- - - - protein hormones are not soluble in phospholipid membrane
      - need to bind to receptors on cell surface membrane and release a second messenger inside cell
    - - can pass through membrane into cell and nucleus
      - to have a direct effect on dna
- - - - zona glomerulosa= the outermost layer of adrenal cortex which secretes mineralocorticoids
      - zona fasciculata= the middle layer which secretes glucocorticoids such as cortisol
      - zona reticularis= the innermost layer which is secretes precursor molecules that are used to make sex hormones
    - - secretes adrenaline and noradrenaline
  - - - protein synthesis
        
        these hormones are STEROID HORMONES which can enter target cell via plasma membrane by dissolving
        
        they bind to specific receptors in cytoplasm with complementary shape
        
        receptor-steroid complex enters the nucleus of the target cell and binds to another receptor on the chromosomal material
        
        binding stimulates production of mrna via transcription which codes for production of a protein
        
        adrenal cortex uses cholesterol to produce hormones
      - mineralocorticoids help control concs of sodium and potassium ions in blood, involved in maintaining blood pressure, e.g. aldosterone acts on cells in dct and collecting duct in kidney increasing Na+ absorption, decreasing K+ absorption, increases water retention so increases bp
      - glucocorticoids help control the metabolism of carbohydrates, fats and proteins in liver, cortisol is released in response to stress or low bp stimulating production of glucose from glycogen in liver
      - precursor androgens (from zona recticularis) which are absorbed by testes/ovaries and are converted into sex hormones which regulate production of gametes and develop secondary sexual characteristics
    - - adrenaline is polar so can't enter plasma membrane like steroid hormones so is detected by specific receptors on membrane
      - many cells have adrenaline receptors so effect is widespread
      - main effects: relaxing smooth muscle in bronchioles, increasing stroke volume of heart, increasing heart rate, causing vasoconstriction to raise bp, stimulates conversion of glycogen to glucose in liver, dilating pupils, inhibiting action of gut, erector pili muscles to contract causing hairs to stand up
- - - - 1) cell membrane contains potassium and calcium ion channels
      - 2) the potassium ion channels are normally open so K+ diffuse out making inside of cell more negative (pd is -70mv)
      - 3) when blood glucose conc is high, glucose moves into the cell and is used for metabolism e.g. respiration to produce ATP via enzyme glucokinase
      - 7) this change in pd causes calcium ion channels to open
      - 5) the extra ATP close the potassium ion channels
      - 6) the accumulation of K+ causes the pd across the membrane to become less negative
      - 8) Ca2+ enter the cell causing the secretion of insulin by making vesicles containing insulin fuse with the cell membrane and release insulin by exocytosis
- - - - exact copy of human insulin so is faster acting and more effective
      - less chance of developing insulin intolerance
      - less chance of rejection/ immune response
      - lower risk of infection
      - cheaper to manufacture
      - manufacturing process is more adaptable to demand
      - less moral objections