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.
1 The ribs from 1-7 are attached to the sternum by coastal cartilage and hence are known as âtrue ribsâ. 2  The 8th, 9th and 10th ribs are not attached directly to the sternum but are attached to the coastal cartilage of the 7th rib, and hence are known as âfalse ribsâ.