Chapter 15: Thorax & Lungs

Thorax & Lungs begins by defining the boundaries of the thoracic cage—formed by the sternum, ribs, and spine—and the internal organization of the lungs into specific lobes and fissures. Key surface landmarks, such as the suprasternal notch and the sternal angle, are emphasized as essential tools for accurately locating underlying structures like the tracheal bifurcation and specific intercostal spaces during procedures like chest tube insertion or decompression. The text details the mechanics of respiration, highlighting the diaphragm as the primary muscle of inspiration and the role of accessory muscles, such as the sternocleidomastoids and scalenes, which become visible when respiratory effort increases due to disease. The health history portion focuses on a systematic evaluation of common respiratory symptoms, including various types of shortness of breath, chronic cough, and the significance of different sputum characteristics. It differentiates between pulmonary and cardiovascular causes of chest pain and provides screening protocols for obstructive sleep apnea using tools like the Epworth Sleepiness Scale. The physical examination section is built upon the four classic pillars: inspection, palpation, percussion, and auscultation. Practitioners are taught to observe respiratory patterns, assess for symmetry in chest expansion, and utilize tactile vibrations to identify areas of lung consolidation or fluid accumulation. The percussion technique is used to distinguish between resonant, air-filled healthy tissue and the dullness associated with conditions like pneumonia or pleural effusion. Auscultation allows for the identification of normal breath sounds, such as vesicular and bronchial, as well as adventitious sounds like crackles, wheezes, and rhonchi, which serve as critical clues for diagnosing underlying pathology. Advanced vocal tests, including egophony and whispered pectoriloquy, are described as methods to confirm clinical findings. Finally, the chapter addresses health promotion, emphasizing the importance of smoking cessation and annual low-dose computed tomography (LDCT) for high-risk individuals to improve lung cancer survival rates.