Biology STAAR Practice Test 2026 – Comprehensive All-in-One Guide to Mastering the State of Texas Readiness Exam!

The lungs are the organs primarily responsible for the process of inhalation. During inhalation, the diaphragm and intercostal muscles contract, expanding the thoracic cavity and lowering the pressure within the lungs relative to the outside atmosphere. This pressure difference allows air to flow into the lungs. The lungs contain alveoli, which are tiny air sacs where gas exchange occurs, bringing oxygen into the bloodstream and removing carbon dioxide. This vital role makes the lungs central to the respiratory process, highlighting their function in facilitating inhalation effectively. Other organs, such as the heart, liver, and kidneys, play crucial roles in the body's overall function, but they are not directly involved in the mechanics of breathing.