L17 - Respiratory control

• What are the primary structures involved in respiratory control?

  Medulla and pons
• What is the role of the medullary respiratory center?

  Generates rhythm for quiet breathing
• How do peripheral sensory inputs affect breathing?

  They modify breathing based on sensory feedback
• What is the function of the pontine respiratory group?

  Smooths transitions between inspiration and expiration
• What are the most important chemical factors influencing breathing?

  CO2, O2, and H+ (pH)
• Where are central chemoreceptors located?

  Throughout the brainstem, including the medulla
• What do peripheral chemoreceptors respond to?

  Changes in O2, CO2, and H+
• Where are peripheral chemoreceptors located?

  Aortic arch and carotid sinus
• What is hypercapnia?

  Elevated blood PCO2 levels
• What physiological response occurs due to hypercapnia?

  Increased ventilation to flush out CO2
• What happens during hypocapnia?

  Respiration is inhibited and slows
• How do central chemoreceptors respond to CO2 levels?

  They mediate 70% of the CO2 response
• What is the effect of increased blood H+ (decreased pH)?

  It may result from increased blood PCO2
• How do higher brain centers influence respiration?

  They modify respiratory rate and depth
• What is the role of the hypothalamus in respiration?

  Signals respiratory centers during strong emotions
• How does the cerebral cortex affect breathing?

  Exerts conscious control over ventilation
• What is the pulmonary irritant reflex?

  Causes bronchoconstriction in response to irritants
• What does the inflation (Hering-Breuer) reflex do?

  Protects lungs from overexpansion by inhibiting inspiration
• What is hyperpnea?

  Increased ventilation in response to metabolic needs
• What neural factors contribute to changes in respiration during exercise?

  Psychological stimuli, motor stimulation, proprioceptor impulses
• What is acute mountain sickness (AMS)?

  Symptoms from rapid transition to high altitudes
• What are the long-term changes during acclimatization to high altitudes?

  Increased ventilation rate and erythropoietin production
• Compare and contrast hyperpnea and hyperventilation.

  • Hyperpnea: Increased ventilation to meet metabolic needs
  • Hyperventilation: Excessive ventilation beyond CO2 removal needs
• Describe the influence of higher brain centers on respiration.

  • Hypothalamus: Modifies rate and depth during emotions
  • Cerebral cortex: Provides conscious control over breathing
• Describe the process and effects of acclimatization to high altitude.

  • Increased ventilation rate
  • Lower than normal Hb saturation
  • Increased erythropoietin production
• True or False: Central chemoreceptors are most sensitive to arterial PO2 levels.

  False
• True or False: Hypercapnia occurs in response to hyperventilation.

  False
• True or False: The anticipation of exercising is one factor that allows for an increase in respiration.

  True
• True or False: An increase in ventilatory rate occurs in individuals acclimatized to high altitude conditions.

  True