Response and Regulation

• Reflex arc


  The path taken by an electrical impulse from stimulus to response via receptor, coordinator (spinal cord), and effector (muscle or gland)
• Withdrawal action reflex


  • Automatic reaction to a hot pan causing quick withdrawal
• Negative feedback


  A change from the balance in optimal internal conditions results in the body's hormonal and nervous system compensating for the change and restoring the balance
• Regulating glucose


  1. Eating increases glucose in blood

  2. Pancreas detects increase and releases insulin

  3. Insulin travels to liver and liver turns glucose into glycogen for storage

  4. Glucose level decreases to normal

  5. Exercising decreases glucose in blood

  6. Pancreas detects decrease and releases glucagon

  7. Glucagon tells liver to turn stored glycogen into glucose and release into blood

  8. Glucose levels increase to normal
• Diabetes is a condition where you are unable to control your own blood glucose levels
• In type I diabetes the body does not release insulin, in type II diabetes the body cells do not respond to the chemical signal from insulin
• Regulating temperature


  1. Too hot: Sweating, Vasodilation

  2. Too cold: Hairs stand on end, Shivering, Vasoconstriction
• A diet high in sugars and carbohydrates can lead to obesity and type II diabetes
• Alcohol causes immediate slowing of reaction times and long-term liver, circulatory and heart disease
• stimulus → receptor → sensory neuron → relay neuron→ motor neuron → effector → response.
• Symptoms of diabetes Glucose present in urine detected by Benedict's test