210 Respiratory

Respiratory Module Overview

Key Terms

  • Respiration: Process that involves the use of oxygen to oxidize fuel molecules, producing energy, carbon dioxide (CO2), and water (H2O).

  • Inhalation (Inspiration): Act of drawing air into the lungs.

  • Exhalation (Expiration): Act of expelling air from the lungs.

Major Functions of the Respiratory System

  • Ventilation: Movement of air in and out of the lungs.

  • Language Production: Enables vocalization through manipulation of airflow.

  • Choking Prevention: The larynx protects the airway during swallowing.

  • Immune Protection: Filters and humidifies air, preventing pathogen entry.

Conducting vs. Respiratory Portions of the Respiratory Tract

  • Conducting Portion: Involved in the transport and conditioning of air, includes structures such as the nasal cavity, trachea, and bronchi.

  • Respiratory Portion: Where gas exchange occurs, includes structures like the alveoli and respiratory bronchioles.

Anatomical Divisions

  • Upper Respiratory Tract: Comprises the nasal cavity, paranasal sinuses, pharynx, and larynx.

  • Lower Respiratory Tract: Encompasses the trachea, bronchi, bronchioles, and lungs.

Airway Passage During Inhalation and Exhalation

  1. Nasal Cavity

  2. Pharynx

  3. Larynx

  4. Trachea

  5. Bronchi

  6. Bronchioles

  7. Alveoli (inhalation only)

Nasal Cavity, Paranasal Sinuses, and Pharynx

  • Functions: Warm and moisturize incoming air, filter particles.

  • Epithelial Lining: Lined with pseudostratified ciliated columnar epithelium to trap and move debris out of the airways.

Functions of the Larynx

  • Language Production: Allows for voice and speech.

  • Choking Prevention: Closes during swallowing to protect airway.

Anatomical Features of the Larynx

  • Composed of various cartilages, including:

    • Thyroid cartilage

    • Cricoid cartilage

    • Arytenoid cartilages

  • Contains vestibular folds (false vocal cords) and vocal folds (true vocal cords).

Vocal Folds and Phonation

  • Location: Situated within the larynx.

  • Function: Produce sound by vibrating as air passes through; tension and length alteration allow pitch variation.

Trachea Overview

  • Major Functions: Provides a passage for air to travel to the lungs.

  • Gross Anatomical Features: Located anterior to the esophagus, supported by C-shaped hyaline cartilage rings that maintain airway patency.

Microscopic Anatomy of the Trachea

  • Lined with ciliated epithelium that traps particles.

  • C-shaped Hyaline Cartilage Rings: Provide structural support while allowing flexibility.

Differences Between Bronchi and Bronchioles

  • Bronchi: Cartilage rings, larger diameter; conducts air towards lungs.

  • Bronchioles: No cartilage rings, smaller diameter; wrapped in smooth muscle allowing bronchoconstriction and bronchodilation during airway resistance changes.

Respiratory Membrane

  • Structure: Thin barrier between alveoli and capillaries that facilitates gas exchange.

  • Function: Allows oxygen to enter the bloodstream and carbon dioxide to be expelled.

Pleura and Pleural Cavity

  • Visceral Pleura: Covers lungs; adheres to lung surface.

  • Parietal Pleura: Lines thoracic cavity; provides lubrication and reduces friction during breathing.

  • Serous Fluid: Fills the pleural cavity, enabling smooth movement of lungs.

Comparison of Left and Right Lungs

  • Right Lung: Three lobes (superior, middle, inferior); shorter due to diaphragm shape.

  • Left Lung: Two lobes (superior, inferior); accommodates the heart's position.

Hilum of the Lung

  • Location: Area on the medial surface where blood vessels, bronchi, and nerves enter and exit the lungs.

  • Structures Include: Pulmonary arteries, pulmonary veins, main bronchi, bronchial arteries.