What causes a pulmonary embolism? Blood clots can form for a variety of reasons. Pulmonary embolisms are most often caused by deep vein thrombosis, a condition in which blood clots form in veins deep in the body. The blood clots that most often cause pulmonary embolisms begin in the legs or pelvis.
All ribs are attached posteriorly to the thoracic vertebrae. The neck of the rib is the flattened part that extends laterally from the head. The neck is about 3 cm long, and is placed in front of the transverse process of the lower of the two vertebrae with which the head articulates.
Below them are the twelve thoracic ve â¦ rtebrae, numbered T1 to T12. Each thoaracic vertabra is attached to a set of ribs. In fact, the definition of a thoracic vertabra is that it articulates with a set of ribs. So T1 is the first spine bone connected to the uppermost set of ribs, just below the base of the neck.