Breath sounds have two phases: inspiration and expiration. These phases constitute the respiratory cycle and are crucial for describing Lung sounds And their temporal characteristics. Normal breath sounds are commonly termed 'vesicular'. They generate a gentle, rustling noise resembling the phrase "WOOOOOSH-AHHH." It is important to understand that lung sounds are produced by variations in airflow. Laminar airflow is uniform in velocity and direction and produces no sound. Turbulent airflow, on the other hand, is chaotic in velocity and direction and produces audible vibrations, which can be heard through the patient’s chest wall with a stethoscope. In vesicular breath sounds. Air enters the upper airway, progressing through the larynx and trachea. The inspiratory sounds arise primarily from the lobar and segmental bronchi where turbulent airflow generates audible vibrations. Air progresses into the narrower bronchioles and then to the minuscule sacs known as alveoli, which are responsible for gas exchange. Airflow within these structures is characterised as 'laminar' and does not produce any sounds. The expiratory breath sound is produced by turbulent airflow in the larger bronchi and trachea. In vesicular breath sounds there is no gap between inspiration and expiration, the sound is continuous. During inspiration, air is rapidly pulled into the airways, creating high-pitched and loud sounds. Expiration, on the other hand, is passive, with less forceful airflow, resulting in lower-pitched, shorter, and quieter sound. Vesicular breath sounds can be heard on auscultation of the thorax. Remember that the right lung is divided into three lobes, while the left lung is divided into two. Are no precise anatomical landmarks for lung auscultation, but the commonly accepted locations in medical literature are outlined here. Place the stethoscope's diaphragm on each of these areas. Listen to a complete cycle of inhalation and exhalation, making symmetrical comparisons between the left and right sides as you progress downward on the chest. During anterior thorax auscultation, you'll primarily hear sounds from the upper and middle lobes. On the posterior thoracic surface, auscultation captures minimal sounds from the upper lobes and predominantly the lower lobes of the lungs. Once again, listen to a full inhalation at each point and compare both sides. In summary, vesicular breath sounds encompass distinct characteristics: These sounds are described as soft, low-pitched, and rustling. There's no pause between inspiration and expiration. The inspiratory sound is longer, louder, and higher-pitched compared to expiration. Vesicular sounds are prevalent throughout peripheral chest auscultation. - Inspiratory sound arises from turbulent airflow in lobar and segmental bronchi. - Expiratory sound originates from turbulent airflow in central airways. Let’s move on to look at bronchial breath sounds! Bronchial breath sounds bear a resemblance to the breathing of Darth Vader in "Star Wars. movies" They have a hollow, blowing character that can be likened to the phrase "Koohhhh Purrrrrr." Bronchial breath sounds are produced via the exact same mechanism as vesicular sounds. The Inspiratory phase is generated by turbulent airflow in lobar and segmental bronchi, while the expiratory sounds originate from the larger central airways. But the outcome is a very different sound - Bronchial breath sounds have a loud, hollow and harsh blowing character. There is a distinct pause between inspiration and expiration, and the expiratory phase longer and higher pitched compared to inspiration. Under normal circumstances, bronchial breath sounds are heard when auscultating over the central airways. A similar sound can be heard by listening over the trachea in the neck and they may be heard over the sternal edge at 2nd intercostal space. Posteriorly Bronchial breath sounds can be heard over the vertebral levels C7 to T3. Bronchial breath sounds should not be heard on peripheral auscultation. The reason for this is that Under normal conditions the presence of healthy lung tissue and the overlaying chest wall function as a filter, effectively dampening higher-frequency, harsh bronchial sounds. As a result, what is commonly heard during auscultation peripheral chest is our familiar, soft vesicular sounds. Bronchial breath sounds are heard centrally over the airways because there is no significant overlying lung tissue to filter and soften the sounds . When bronchial breath sounds can be heard on peripheral auscultation, it indicates an abnormality, suggesting the presence of underlying pathologies that enhance the transmission of vibrations from the larger airways. Solid tissue and fluids transmit vibrations more effectively than air. For example in consolidation, seen in pneumonia, the inflammatory process that increases lungs density. The denser tissue transmits vibrations from harsh bronchial sounds, to the surface, manifesting as bronchial breath sounds during auscultation of the peripheral chest. Other pathological scenarios that lead to this effect include: Consolidation Dense lung fibrosis Lung abscess A collapsed lung adjacent to a pleural effusion. In summary, bronchial breath sounds exhibit the following features: The sounds have a Loud, hollow, and blowing quality. There is a pause between inspiration and expiration, and the expiratory phase is longer and higher pitched compared to inspiration. The sounds can be heard normally when auscultating the trachea and central airways. - When heard in the peripheral auscultation, this is abnormal and is usually indicating conditions like consolidation, dense fibrosis, lung abscess, or a collapsed lung above a pleural effusion. This brings us to the end of today's episode. Thank you for stopping by and watching. I really appreciate your support - it means a lot to me. the next episode is going to be about crackles. We’ll do a deep dive on fine and coarse crackles to under stand them better. If you have any other thoughts about topics that you’d like to see covered in the Learn medicine show - comment below! thanks for stopping bye, i’ll see you in the next episode.