Stimuli

• What do stimuli detected by receptors cause heart rate to do?

  speed up or slow down
• What type of receptors detect high blood pressure?

  baroreceptors
• What type of receptors detect low blood pressure?

  baroreceptors
• What type of receptors detect chemical changes in the blood?

  chemoreceptors
• STIMULUS = HIGH BLOOD PRESSURE- describe neurone and transmitter?


  • Impulses sent to medulla
  • Medulla sends impulses along PARAsympathetic neurones
  • These secrete acetylcholine which binds to receptors on the SAN
• What is acetylcholine?


  a neurotransmitter
• STIMULUS = HIGH BLOOD PRESSURE. What is the EFFECTOR AND RESPONSE?

  • Effector = cardiac muscles
  • Response= HR slows down to reduce blood pressure back to normal
• STIMULUS= LOW BLOOD PRESSURE - what is the neurone and transmitter?


  • Impulses sent to medulla
  • Medulla sends impulses along SYMPathetic neurones
  • These secrete noradrenaline which binds to receptors on the SAN
• What is noradrenaline?


  a neurotransmitter
• STIMULUS= LOW BLOOD PRESSURE . What is the effector ?


  cardiac muscles
• STIMULUS= LOW BLOOD PRESSURE . what is the response?


  heart rate speeds up to increase blood pressure back to normal
• STIMULUS: high blood O2, low CO2, or high pH levels. What is the neurone and transmitter?


  • Impulses sent to medulla
  • Medulla sends impulses along PARAsympathetic neurones
  • These secrete acetylcholine, which binds to receptors on the SAN
• STIMULUS: high blood O2, low CO2, or high pH levels. What is the effector?


  Cardiac muscle
• STIMULUS: high blood O2, low CO2, or high pH levels. What is the response?


  Heart rate decreases to return O2, CO2 and pH levels back to normal
• STIMULUS: low blood O2, high CO2, or low pH levels. What is the receptor?


  chemoreceptors
• STIMULUS: low blood O2, high CO2, or low pH levels. What is the neurone and transmitter?


  • Impulses send to medulla
  • Medulla sends impulses along SYMPathetic neurones
  • These secrete noradrenaline, which binds to receptors on the SAN
• STIMULUS: low blood O2, high CO2, or low pH levels. What is the effector?


  Cardiac muscles
• STIMULUS: low blood O2, high CO2, or low pH levels. What is the response?


  Heart rate increases to return O2, CO2 and pH levels back to normal