The direction of the wound is random rather than straight, and it may have multiple branches.[5] Most often caused by an object with a broken or serrated edge, such as a piece of broken glass or metal, but may also be caused by a blow from a blunt object to tissue with bone immediately behind it. Puncture: Sharp object penetrates the tissue and travels inward, but does not move laterally in any direction from the point of entry.[6] Such wounds can be misleading, as they may appear quite small on surface examination, but extend quite deeply into the body, even damaging nerves, blood vessels, or internal organs. They may cause substantial internal bleeding or secondary injuries, such as a collapsed lung, which may not be readily evident during primary assessment.