Respiratory System Flashcards

Blood-Brain Barrier

• A semipermeable membrane protecting the brain.
• Prevents harmful blood substances from entering brain tissue.

Agonal Breathing

• Abnormal, gasping breathing before death.
• Brainstem reflex lasting minutes post-cardiac arrest.

pH and Acidity

• pH measures fluid acidity or alkalinity.
• Lower pH: acidic; higher pH: alkaline.

Kussmaul's Breathing

• Deep, rapid breathing in conditions like diabetic ketoacidosis.
• Removes excess carbon dioxide to reduce acid levels.

"J" Receptors (Juxtacapillary Receptors)

• Located in lung tissue near capillaries.
• Respond to fluid buildup, causing rapid, shallow breathing.

Respiratory Quotient (RQ)

• Metabolic parameter in the alveolar gas equation.
• Ratio of CO2 produced to O2 consumed.
• Estimates alveolar oxygen levels.
• Normal RQ: approximately 0.8.

Diffusion

• Movement of molecules from high to low concentration.
• In lungs: oxygen moves from alveoli to blood.

Dalton's Law

• Total pressure of a gas mixture equals the sum of partial pressures.

Partial Pressure of Oxygen in Alveoli

• At rest: approximately 100 mm Hg.

Water Vapor Pressure at 37°C

• Becomes 47 mm Hg when air is warmed to body temperature.
• Affects inspired gas calculations.

Oxygen Percentage in Room Air

• Approximately 20.95% at sea level.

Arterial Oxygen Notation (PaO2)

• Represents partial pressure of oxygen in arterial blood.
• Used in ABG interpretation.
  • PAO_2: alveolar oxygen
  • FiO_2: inspired oxygen
  • PaCO_2: arterial carbon dioxide

Alveolar Dead Space

• Alveoli ventilated but not perfused with blood.
• No gas exchange occurs.

Normal Arterial Oxygen Level (PaO2)

• Healthy adult range: 80-100 mm Hg.

Cerebrospinal Fluid (CSF)

• Clear, protective fluid around brain and spinal cord.
• Cushions CNS and removes waste.