Why do you need two different circuits of blood vessels in your body

You need 2 circuits of blood vessels in your body so that oxygenated and deoxygenated blood don't mix.

Explanation:

Arteries carry oxygen-rich blood from your heart to the rest of your body so that you can function. The oxygen is used, and the blood is taken back to the heart through veins to start the cycle over. I hope that answers your question!

the oblique cord is a ligament between the ulnar and radius bones in the lower arm near the elbow. it takes the form of a small, flattened band, extending downward and lateralward, from the lateral side of the ulnar tuberosity at the base of the coronoid process to the radius a little below the radial tuberosity.