L1-3 quiz

• only target organs respond to presence of specific hormone because:

  only those organ cells have the appropriate receptors
• steroid hormones pass through the target cell's plasma membrane
• steroid hormones bind to intracellular receptor proteins
• steroid hormones-> hormone-receptor complex binds to specific regions of DNA
• steroid hormones-> hormone receptor complex activates genes, producing action in the target cells
• steroid hormones are produced by the adrenal glands, ovaries, testes, and pancreas
• steroid hormones do not use second messengers to achieve their efforts
• categories of hormones:

  • polypeptides
  • glycoproteins
  • amines
  • steroids
• second messengers act inside cells, in response to hormones
• second messenger system molecules of adrenaline:

  • G protein
  • adenyl cyclase
  • protein kinase
  • cyclic AMP
• insulin achieves its effects by binding to cell surface receptors
• noradrenaline acts both as a neurotransmitter and a hormone synthesised by the adrenal medulla
• homeostasis is achieved through the actions of 2 major regulatory systems, the nervous system and the endocrine system
• a hormone is a regulatory chemical that is secreted into the blood by an endocrine gland
• some intercellular regulatory molecules that exert only very local effects are called _ regulators 


  paracrine
• para means


  next to or adjacent
• water soluble hormones cannot pass through the plasma membrane, instead rely on _ messengers within their target cells to mediate their action

  second