Anatomical landmarks
Individual vertebrae of the human vertebral column can be felt and used as surface anatomy, with reference points are taken from the middle of the vertebral body. This provides anatomical landmarks that can be used to guide procedures such as a lumbar puncture and also as vertical reference points to describe the locations of other parts of human anatomy, such as the positions of organs. Other animals
Variations in vertebrae
The general structure of vertebrae in other animals is largely the same as in humans. Individual vertebrae are composed of a centrum (body), arches protruding from the top and bottom of the centrum, and various processes projecting from the centrum and/or arches. An arch extending from the top of the centrum is called a neural arch, while the haemal arch or chevron is found underneath the centrum in the caudal (tail) vertebrae of fish, most reptiles, some birds, some dinosaurs and some mammals with long tails. The vertebral processes can either give the structure rigidity, help them articulate with ribs, or serve as muscle attachment points. Common types are transverse process, diapophyses, parapophyses, and zygapophyses (both the cranial zygapophyses and the caudal zygapophyses). The centrum of the vertebra can be classified based on the fusion of its elements. In temnospondyls, bones such as the spinous process, the pleurocentrum and the intercentrum are separate ossifications. Fused elements, however, classify a vertebra as having holospondyly. A vertebra can also be described in terms of the shape of the ends of the centrum.
A papillary fibroelastoma is a primary tumor of the heart that typically involves one of the valves of the heart. Papillary fibroelastomas, while considered generally rare, make up about 10 percent of all primary tumors of the heart. They are the third most common type of primary tumor of the heart, behind cardiac myxomas and cardiac lipomas. Signs and symptoms
A papillary fibroelastoma is generally considered pathologically benign, however outflow obstruction or embolism can be associated with syncope, chest pain, heart attack, stroke and sudden cardiac death. Symptoms due to papillary fibroelastomas are generally due to either mechanical effects of the tumor or due to embolization of a portion of the tumor to a distal organ. In particular, chest pain or syncope may be due to transient occlusion of the left main coronary artery by the tumor, while a heart attack or sudden cardiac death may be due to embolization of a portion of the tumor into a coronary artery. Diagnosis
Papillary fibroelastoma are typically found and accurately diagnosed by imaging. The diagnosis is confirmed by pathology. Histologically, papillary fibroelastomas have branching avascular papillae, composed of collagen, that are covered by endothelium. Treatment
If the tumor is found incidentally in an asymptomatic person, the treatment approach is controversial. Certainly a conservative approach is warranted in certain individuals. If the tumor is large, greater than 1 cm in asymptomatic patients, and pedunculated, a case may be made for surgical excision prior to symptoms developing due to the higher risk of embolism.