Which vessel is listed as a blood collection site in rats besides jugular and retro-orbital?

• A. Cranial Vena Cava
• B. Coronary Vein
• C. Pulmonary Vein
• D. Femoral Vein

Answer: (A)

In rats, a central vein used for blood collection besides the jugular and retro-orbital is the cranial vena cava. This large vein drains blood from the head and upper body, so drawing from it allows a larger sample to be obtained and is useful when a higher volume is needed or other peripheral sites are less practical. Accessing the cranial vena cava is more invasive and requires proper anesthesia and technique because of its location near the lungs and heart, which brings greater risk of complications. The other vessels listed are not typical routine sources: the coronary vein and pulmonary vein are small or hard to access for consistent sampling, and while the femoral vein can be used, it is not the common central-site alternative emphasized in standard protocols.