Which is on part of the immune system that helps protect the body from diseases?

Mucus

Mucus works as a selective barrier to sensitive organs in the body.
Harmful microbes that could pass by the nose into the lungs and cause infections are taped earlier and excreted by mucus.
Mucus traps invading pathogens preventing them from reaching sensitive parts of the body thereby preventing diseases.

1.controls blood flow2.controls oxygen flow3.carries oxygen rich blood to veins

Answerrespiratory illness;