Unit
- Respiratory system purpose: The respiratory system supplies oxygen to the blood and removes carbon dioxide produced by cellular metabolism. It also filters, warms, and humidifies inspired air. Air moves through conducting airways to gas exchange surfaces, where diffusion occurs across a thin membrane. This process supports every organ system, so respiratory impairment creates multisystem consequences.
- Major divisions: The respiratory tract divides into the upper airway, including nose, nasal cavity, pharynx, and larynx, and the lower airway, including trachea, bronchi, bronchioles, and alveoli. The upper airway conditions incoming air temperature and humidity, while the lower airway conducts air to the alveoli and participates in gas exchange. Each division has distinct roles in health and disease.
- Thoracic structures: The lungs sit within the thoracic cavity protected by the rib cage. The pleura, a double-layered membrane, surrounds each lung and creates a potential space with negative pressure. This pressure gradient allows the lungs to expand and recoil during breathing. Mediastinal structures, including the heart and major vessels, occupy the central chest and influence respiratory function through shared circulation.
- Functional zones: Airways are classified into conducting zones and respiratory zones. The conducting zone includes trachea through terminal bronchioles, while the respiratory zone includes respiratory bronchioles, alveolar ducts, and alveoli. The conducting zone has no gas exchange and is considered anatomical dead space. Respiratory zone structures perform gas exchange with the pulmonary capillaries through their extensive surface area.
- Alveolar surface: Alveoli are small air sacs with thin walls composed of type I pneumocytes. Type II pneumocytes produce surfactant, which reduces surface tension and prevents collapse. The alveolar-capillary membrane is extremely thin, allowing oxygen and carbon dioxide to diffuse rapidly. Damage to this membrane, as seen in many interstitial lung diseases, impairs gas transfer.
- Pulmonary circulation: Blood flows from the right ventricle through the pulmonary arteries into the capillaries surrounding the alveoli. Ventilation and perfusion must match for efficient gas exchange. In healthy upright individuals, both ventilation and perfusion increase from apex to base, creating regional differences. Conditions that disrupt matching, such as pulmonary embolism or atelectasis, lead to hypoxemia.
- Respiratory defense: The respiratory tract has multiple defense layers, including nasal hairs, mucus, cilia, and alveolar macrophages. The mucociliary escalator moves trapped particles upward toward the pharynx, where they are swallowed or expectorated. Cough and sneeze reflexes protect the lower airway. Smoking and chronic infection impair these defenses, increasing susceptibility to respiratory pathogens.
- System integration: The respiratory system interacts closely with the cardiovascular, renal, and nervous systems. Oxygen delivery depends on cardiac output and hemoglobin, while carbon dioxide elimination influences acid-base balance. Breathing is controlled by central chemoreceptors that sense pH and carbon dioxide, and peripheral chemoreceptors that sense oxygen. Disorders in one system often manifest as respiratory symptoms.
Scope of Practice
Role: Pulmonary Clinic Administrative Coordinator
Within scope:
- Scheduling patient appointments and coordinating procedure bookings such as spirometry and sleep studies
- Collecting and updating patient demographic and insurance information in the electronic health record
- Providing pre-visit instructions and educational materials about respiratory tests as directed by clinical staff
- Managing referral workflows and prior authorization requests for diagnostic studies
Outside scope:
- Interpreting pulmonary function test results or making diagnostic determinations
- Recommending treatment plans or adjusting prescribed respiratory therapies
- Performing clinical assessments like auscultation or oxygen saturation measurement
- Providing medical advice about respiratory symptoms or medication side effects
Quick Revision
- The respiratory system oxygenates blood and removes carbon dioxide through the upper and lower airway divisions.
- The conducting zone conditions air and the respiratory zone performs gas exchange at the alveolar-capillary membrane.
- Ventilation-perfusion matching and surfactant production are required for efficient oxygen delivery.
- Non-clinical staff support respiratory services through scheduling, documentation, and patient education while staying within defined scope.