Final answer:
The statement 'All crackles have pathologic causes' is False.
Step-by-step explanation:
The statement 'All crackles have pathologic causes' is False.
Crackles, also known as rales, are abnormal lung sounds that can be heard during auscultation when listening to a person's breathing. They are often associated with certain respiratory conditions and diseases.
However, not all crackles have pathologic causes. Some crackles can occur in non-pathologic situations, such as when a person inhales deeply or when there is excess fluid in the airways that is not related to a disease.