Chapter 19: Thorax and Lungs

Thorax and Lungs begins with a detailed overview of surface landmarks, such as the sternal angle and costal margins, which serve as essential diagnostic signposts for underlying structures including the tracheal bifurcation and lung borders. The text explains the complex mechanics of ventilation, detailing how the diaphragm and accessory muscles facilitate gas exchange, regulate acid-base balance, and respond to humoral stimuli like hypercapnia. Special attention is directed toward developmental competence, tracing respiratory transitions from neonatal surfactant production to the physiological shifts in pregnancy and the structural changes associated with geriatric lung compliance. Practitioners are guided through a systematic physical examination involving inspection of chest configuration, palpation for symmetric expansion and tactile fremitus, percussion to differentiate resonance from abnormal dullness, and auscultation of various breath sounds. The curriculum covers the identification of adventitious noises such as crackles, wheezes, and stridor, while also integrating voice sound tests like bronchophony and egophony for advanced practice. Subjective data collection is prioritized, focusing on cough characteristics, smoking history via the five As counseling framework, and environmental risk factors. Ultimately, the material provides a comprehensive framework for differential diagnosis, contrasting healthy pulmonary status with pathological conditions including chronic obstructive pulmonary disease (COPD), asthma, pneumonia, pneumothorax, and modern respiratory complications such as COVID-19 viral pneumonia.