Which procedure involves looking inside the body using an instrument to examine the interior of a hollow organ or cavity?

• A. TTP
• B. CT Scan
• C. Endoscopy
• D. Idiopathic

Answer: (C)

Endoscopy involves looking inside the body using an instrument to examine the interior of a hollow organ or cavity. An endoscope—a flexible tube with a light and camera—is inserted through a natural opening or a small incision, allowing direct visualization of internal surfaces such as the esophagus, stomach, colon, airways, bladder, or joints. This method can also enable therapeutic actions like taking biopsies or removing polyps during the same procedure. The other options don’t fit because a CT scan provides external radiologic images without inserting a scope, while terms like TTP and idiopathic describe neither a visualization procedure nor direct internal examination.