Which procedure involves collecting blood by puncturing a vein?

• A. Phlebotomy
• B. Paracentesis
• C. Proctosigmoidoscopy
• D. PSA

Answer: (A)

Collecting blood by puncturing a vein is phlebotomy. This procedure, often called venipuncture, is done to obtain a blood sample for laboratory testing. A needle is inserted into a vein—commonly in the bend of the elbow at a major vein like the median cubital—and blood is drawn into collection tubes.

Paracentesis involves removing fluid from the abdominal cavity, not blood. Proctosigmoidoscopy is an endoscopic exam of the rectum and sigmoid colon. PSA refers to a blood test for prostate-specific antigen; the sample for that test is obtained by phlebotomy, but the term describes the test itself rather than the collection method.