What is pulmonary ventilation?
The process of air exchange between the atmosphere and the lungs.
Define inhalation (inspiration).
An active process where the diaphragm contracts and thoracic volume increases, leading to a decrease in intrapulmonary pressure.
What occurs during exhalation (expiration)?
A passive process where the diaphragm relaxes, thoracic volume decreases, and intrapulmonary pressure increases.
What is Boyle's Law?
At constant temperature, the pressure of a gas varies inversely with its volume.
What is tidal volume (TV)?
The amount of air inhaled or exhaled with each breath under resting conditions, approximately 500 mL.
What is inspiratory reserve volume (IRV)?
The amount of air that can be forcefully inhaled after a normal tidal volume inhalation, approximately 1900-3100 mL.
Define expiratory reserve volume (ERV).w
The amount of air that can be forcefully exhaled after a normal tidal volume exhalation, approximately 700-1200 mL.
What is residual volume (RV)?
The amount of air remaining in the lungs after a forced exhalation, approximately 1100-1200 mL.
What is functional residual capacity (FRC)?
The volume of air remaining in the lungs after a normal tidal volume expiration, calculated as ERV + RV.
What is vital capacity (VC)?
The maximum amount of air that can be expired after a maximum inspiratory effort, calculated as TV + IRV + ERV.
Define total lung capacity (TLC).
The maximum amount of air contained in the lungs after a maximum inspiratory effort, approximately 4200-6000 mL.
What factors affect pulmonary ventilation?
Air pressure changes, surface tension of alveolar fluid, lung compliance, and airway resistance.
What is the role of pulmonary surfactant?
A detergent-like complex that reduces surface tension in smaller alveoli, preventing collapse and reducing the energy needed to expand the lungs.
What is the significance of Dalton's Law?
It states that the total pressure is the sum of the pressures exerted independently by each gas in a mixture.
Explain Henry's Law.
The amount of gas that dissolves in a liquid is proportional to its partial pressure and solubility.
What is external respiration?
Gas exchange between the lungs and blood in the pulmonary capillaries, where blood gains O2 and releases CO2.
Define internal respiration.
Gas exchange between blood in systemic capillaries and cells, where blood gains CO2 and releases O2.
What is the role of chemoreceptors in respiration?
They respond to changes in blood PCO2, PO2, and pH to regulate breathing rate and depth.
What is the normal respiratory rate for a healthy adult?
Approximately 12-15 breaths per minute.
What is hyperpnea?
An increased respiratory rate due to extra oxygen needs, often occurring during exercise.
What are the main types of chronic obstructive pulmonary disease (COPD)?
Emphysema and chronic bronchitis.
What characterizes asthma?
A chronic inflammatory disorder with hypersensitivity of the airway and reversible airway obstruction.
What is the significance of ventilation/perfusion coupling?
It ensures efficient gas exchange by matching the amount of gas reaching the alveoli with blood flow in pulmonary capillaries.
How is oxygen primarily transported in the blood?
About 98.5% of O2 is transported by binding to hemoglobin in red blood cells.
What factors influence the binding and dissociation of oxygen from hemoglobin?
Partial pressure of O2, partial pressure of CO2, blood pH, temperature, and levels of 2,3-bisphosphoglycerate (BPG).