Gas Exchange and Transport

• Atmospheric air has higher nitrogen and oxygen levels compared to alveolar air.
• Alveolar air contains more carbon dioxide and water vapor than atmospheric air.
• According to Dalton's Law, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each individual gas.
• Henry's Law states that the solubility of a gas in a liquid is proportional to the partial pressure of the gas above the liquid.
• Oxygen is primarily transported in the blood by binding to hemoglobin within red blood cells.
• Hypoxia refers to a deficiency of oxygen reaching the tissues of the body.
• Types of hypoxia include hypoxic, anemic, stagnant, and histotoxic hypoxia.
• Carbon dioxide is transported in the blood as bicarbonate ions, as dissolved gas, and in the form of carbamino compounds.
• The ventral respiratory group (VRG) in the brainstem serves as the primary rhythm-generating center for both inhalation and exhalation.
• The dorsal respiratory group (DRG) integrates sensory inputs to modulate respiratory rhythm.
• Pons respiratory group helps smooth out the transitions between inhalation and exhalation.
• Reciprocal inhibition prevents simultaneous contraction of inhalation and exhalation muscles.
• Chemical factors such as carbon dioxide, oxygen, and hydrogen ion levels in the blood influence breathing rate and depth.
• Rising plasma PCO2 stimulates the medulla oblongata chemoreceptors, which increases breathing rate.
• Decreased pH causes increased breathing to normalize blood pH.
• Peripheral chemoreceptors detect changes in arterial PO2 and pH.
• Hyperventilation is an increased breathing rate that exceeds the body's needs for carbon dioxide removal.
• Low CO2 causes cerebral vasoconstriction, reducing blood flow to the brain.
• Ischemia refers to an insufficient blood supply to tissues.
• Dizziness from hyperventilation is caused by low CO2 levels and subsequent cerebral ischemia.
• Swimmers sometimes use hyperventilation to extend the duration they can hold their breath.
• After hyperventilation, PCO2 levels must increase sufficiently to trigger respiration.
• The hypothalamus can regulate respiratory rate during strong emotions.
• The cerebral cortex allows for conscious control of ventilation behavior.
• Smelling salts contain volatile compounds that trigger an inhalation reflex.
• Ammonium carbonate is the active ingredient in smelling salts.
• Ammonia gas irritates mucous membranes, stimulating a sympathetic reflex.
• Vigorous respiration refers to deep, forceful breathing during intense exercise.
• Psychological stimuli, such as anticipation of exercise, can affect respiration.
• Cortical motor stimulation involves the simultaneous activation of muscles and respiratory centers.
• Proprioceptors are sensory receptors that provide information to respiratory areas during exercise.
• Anaerobic respiration occurs when oxygen supply is insufficient during intense exercise.
• Acute Mountain Sickness is an illness that can occur from rapid altitude change above 2.5 km.
• Acclimatization is the long-term adaptation to high altitude conditions.
• Erythropoietin is a hormone that increases red blood cell production.
• Pulmonary Function Tests evaluate respiratory function using a spirometer.
• Obstructive disorders are characterized by reduced airflow and increased residual volume.
• Restrictive disorders are characterized by reduced lung volumes and capacity.
• Hyperinflation is a lung condition resulting from obstructive pulmonary disorders.

Lung Capacity

• Total Lung Capacity (TLC) is the maximum amount of air the lungs can hold.
• Vital Capacity (VC) is the maximum amount of air that can be expelled after a maximum inhalation.
• Inspiratory Reserve Volume (IRV) is the extra air that can be inhaled after a normal inhalation.
• Expiratory Reserve Volume (ERV) is the extra air that can be exhaled after a normal exhalation.
• Residual Volume (RV) is the air remaining in the lungs after maximal exhalation.
• Restrictive pulmonary disorders limit lung expansion due to scar tissue.

Volume Measurements

• Vital capacity is the maximum amount of air exhaled after maximum inhalation.
• Total lung capacity is the total volume of air in the lungs after maximum inhalation.
• Residual volume is the air remaining in the lungs after forced exhalation.
• Expiratory reserve volume is the additional air exhaled after normal expiration.

COPD and Related Issues

• Chronic obstructive pulmonary diseases (COPD) are progressive lung diseases that cause airflow obstruction.
• Air hunger refers to the labored breathing sensation due to insufficient airflow.
• Emphysema is a type of COPD characterized by enlarged alveoli and deterioration of alveolar walls.
• Chronic bronchitis is a type of COPD characterized by excessive mucus production and airway inflammation.
• Alpha-1 antitrypsin deficiency is a genetic condition that increases the risk of emphysema.
• Neutrophil elastase is an enzyme that breaks down lung tissue elasticity.
• Asthma is an inflammatory airway disease that causes wheezing and coughing.
• Bronchospasms are contractions of airway muscles causing obstruction.
• Hyperinflation is excess air trapped in the lungs, which reduces their efficiency.
• Barrel chest is a change in chest shape due to lung hyperinflation.
• Accessory muscles are muscles used to aid breathing in respiratory distress.
• Pulmonary infections frequently affect the lungs when COPD is present.
• Environmental pollutants are substances in the environment that can harm one's health.
• Inflammatory exudate is fluid containing immune cells found in inflamed airways.
• Dyspnea is difficulty breathing or shortness of breath.
• Hyperpnea is a increased breathing rate due to metabolic demand.
• Acclimatization to high altitude involves physiological adjustments to lower oxygen availability.

Explore the differences between atmospheric and alveolar air composition. Understand Dalton's and Henry's Laws governing gas behavior. Learn about oxygen and carbon dioxide transport mechanisms, types of hypoxia, and respiratory control centers.