Heart

Heart Regulation

Fundamentals:

• 1)Receptors regulation
  • Baroreceptors - carotid arteries and aortic arch
  • Chemoreceptors - carotid arteries and aortic arch
• 2)ANS will regulate cardiac output by INC or DEC the Heart Rate
  • DEC arterial pressure and receptors send message to medulla of Brain Stem
    • Medulla activates the Sympathetic Nervous System of ANS
      • Target organ is the SA Node to INC Heart Rate --> INC BP
      • Target organ is adrenal medulla to release Epinephrine --> INC Heart Rate
      • Vasoconstriction to nonintegral organs (Brain & Heart)
  • INC arterial pressure
    • Vagus Nerve/10th Cranial Nerve activates the Parasympathetic Nervous System of ANS
      • Neurotransmitters DEC the Heart Rate
• 3)Medicinal
  • Beta blockers
    • Block the sympathetic b-receptors
    • Reduce the heart rate and blood pressure ---> DEC cardiac workload and reducing the heart’s need for O2

Concepts:

• Causes of DEC arterial pressure
  • Hemorrhage