Final answer:
The inferior vena cava filter is placed in the inferior vena cava to prevent blood clots from traveling to the heart or lungs.
Step-by-step explanation:
The inferior vena cava filter is placed in the inferior vena cava, which is the largest vein entering the inferior vena cava and drains blood from the kidneys and lower body.
Its purpose is to catch blood clots that may form in the legs or pelvis and prevent them from traveling to the heart or lungs. This filter is usually inserted in patients who are at high risk of developing blood clots but cannot take blood thinners.