Final answer:
Stertorous respirations, stridor, and wheezes are abnormal respiratory sounds that can occur during inspiration, expiration, or both, reflecting different underlying respiratory conditions. Understanding the phase of respiration where these sounds are heard helps in diagnosing the condition causing them.
Step-by-step explanation:
Stertorous respirations, stridor, and wheezes are abnormal breathing sounds that can occur during different parts of the respiratory cycle. These sounds can be indicative of various respiratory conditions. Understanding when they occur is important for diagnosis and treatment. Pulmonary ventilation comprises two major steps: inspiration (or inhalation) and expiration (or exhalation).
Inhalation begins as the diaphragm contracts and moves downward while the rib muscles contract, which causes the thoracic cavity to expand and the air pressure inside to decrease, allowing atmospheric air to flow into the lungs. Expiration occurs when these muscles relax and the thoracic cavity reduces in volume, resulting in air being pushed out due to an increase in air pressure inside the lungs above atmospheric pressure.
Abnormal respiratory sounds such as stertorous respirations, stridor, and wheezes can be heard during either inspiration, expiration or both, depending on the underlying cause. Wheezing is typically heard during expiration but may also be present on inspiration in severe airway obstruction. Stridor is usually heard during inspiration as it's associated with upper airway obstruction. Stertorous breathing is often noted on inspiration due to partial airway obstruction that could be at the level of the throat or nasopharynx.