Excretion & Hormonal Communication

• What are the outer and inner regions of adrenal glands called?

  • Outer: adrenal cortex
  • Inner: adrenal medulla
• Name the region where aldosterone hormone is produced.

  Adrenal cortex
• Name a hormone produced in the Adrenal medulla.

  Adrenaline
• Name the two types of cells the islets of Langerhans contain:

  • alpha cells
  • beta cells
• What do the alpha cells from the islets of Langerhans secrete?

  Glucagon
• What do the beta cells from the islets of Langerhans secrete?

  Insulin
• Suggest how adrenaline brings about a response inside the cells of the sino-atrial node.

  • adrenaline acts as a first messenger and binds to receptors on plasma membrane that activates an effector molecule called enzyme adenyl cyclase
  • that activates an effector molecule called enzyme adenyl cyclase
  • which converts ATP to cyclic AMP (cAMP) which is a secondary messenger
  • results in depolarisation
• Type 1 diabetes results from a shortage of beta cells in the pancreas, therefore there is a lack of insulin
• What does the Central Nervous System (CNS) consist of?

  • Brain
  • Spinal cord
• What does the Peripheral System consist of?

  • Sensory nerones
  • Motor neurones
• Describe the sequence of actions that occur once adenylyl cyclase is activated in the target liver cells.

  • catalyses the synthesis of cyclic AMP from ATP
  • cyclic AMP activates enzymes responsible for conversion of glycogen to glucose
• Name the structures:

  K = Islet of Langerhans

  L = blood vessel