biology paper 1 aqa

• What is a hormone?

  a chemical that controls bodily functions
• What do you know about hormones?


  Chemical messengers
• How do hormones travel around the body?


  Through the bloodstream.
• Give some examples of where hormones are released from In the endocrine system?


  Pancreas, adrenal glands, pituitary gland, thyroid gland, ovaries, testes.
• Name the two hormones that control blood glucose Concentration and explain what they do within the body?


  Insulin and glucagon. Insulin lowers blood glucose levels by promoting glucose uptake by cells, while glucagon raises blood glucose levels by stimulating the liver to release stored glucose.
• What hormones control blood glucose?


  Insulin and glucagon.
• Why does blood glucose need regulating?

  Homeostasis
• What is homeostasis?

  Homeostasis is the body's ability to maintain a stable internal environment despite external changes.
• What are the roles of the hormones in the regulation of glucose?


  ….

  Insulin lowers blood glucose by promoting its uptake and storage, while glucagon raises blood glucose by stimulating the liver to release
• Explain how negative feedback controls the blood glucose concentration during the first one and a half hours after a meal?


  .

  after a meal, rising blood glucose triggers insulin release, promoting glucose uptake and storage, and as glucose levels normalize, insulin secretion decreases, maintaining balance through negative feedback.
• What is negative feedback?

  regulation - Negative feedback is a process that detects changes in a system and triggers responses to bring it back to its normal state, like insulin lowering blood sugar when it rises.
• What happens to blood sugar after a meal?


  The blood sugar rises
• Why does blood glucose drop?

  because it gives your body energy
• what are some of the adaptations of nerve cells that makes them good for carrying nerve impulse?


  .

  Neurons are good at carrying nerve impulses because they have long axons, myelin for faster signals, gaps to jump between, branched dendrites to receive signals, and terminals to release chemicals.
• explain how impulses travel over a synapse?


  An electrical impulse travels along an axon, causing the neuron to release neurotransmitters. These chemicals cross the synapse and bind to receptors on the next neuron, which then stimulates it to transmit the electrical impulse
• Explain what happens during a reflex?


  .

  A reflex, or reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus. A reflex is made possible by neural pathways called reflex arcs which can act on an impulse before that impulse reaches the brain.