THE VERTEBRAL COLUMN as 
DESCRIPTIVE TERMS 
The surfaces of the bones present a great variety of eminences and depressions, 
as well as perforations. The prominences and cavities may be articular, or non- 
articular, furnishing attachment to muscles, tendons, ligaments, or fascia. A 
number of descriptive terms are used to designate these features, and the following 
are some of those in general use: 
Process (Processus) is a general term for a prominence. 
A tuberosity (Tuber, Tuberositas) is a large, rounded projection; a tubercle 
(Tuberculum) is a smaller one. 
The term trochanter is applied to a few prominences, e. g., the trochanters of 
the femur. 
A spine (Spina) or spinous process (Processus spinosus) is a pointed projection. 
A crest (Crista) is a sharp ridge. 
A line (Linea) is a very small ridge. 
A head (Caput) is a rounded articular enlargement at the end of a bone; it 
may be joined to the shaft by a constricted part, the neck (Collum). 
A condyle (Condylus) is an articular eminence which is somewhat cylindrical; 
a non-articular projection in connection with a condyle may be termed an epi- 
condyle (Epicondylus). 
A trochlea is a pulley-like articular mass. 
A glenoid cavity (Cavitas glenoidalis) is a shallow articular depression, and a 
cotyloid cavity or acetabulum is a deeper one. 
The term facet is commonly applied to articular surfaces of small extent, 
especially when they are not strongly concave or convex. 
The terms fossa, fovea, groove or sulcus, and impression are applied to various 
forms of depressions. 
A foramen is a perforation for the transmission of vessels, nerves, ete. 
A sinus is an air-cavity within a bone or bones; it is lined with mucous mem- 
brane and communicates with the exterior. 
Other terms, such as canal, fissure, notch, etc., require no explanation.’ 
THE VERTEBRAL COLUMN 
The vertebral column (Columna vertebralis) is the fundamental part of the 
skeleton. It consists of a chain of median, unpaired, irregular bones which 
extends from the skull to the end of the tail. In the adult certain vertebra have 
become fused to form a single bony mass with which the pelvic girdle articulates. 
Vertebree so fused are termed fixed (or ‘‘false’’) vertebra (Vertebree immobiles), as 
distinguished from the movable (or “‘true’’) vertebra (Vertebrze mobiles). 
The column is subdivided for description into five regions, which are named 
according to the part of the body in which the vertebre are situated. Thus the 
vertebre are designated as cervical, thoracic, lumbar, sacral, coccygeal (Vertebrie 
cervicales, thoracales, lumbales, sacrales, cocecygexe). The number of vertebrae in 
a given species is fairly constant in each region except the last, so that the verte- 
bral formula may be expressed (for the horse, for example) as follows: 
C7TisLeSsCyis-21. 
The vertebre in a given region have characters by which they may be dis- 
tinguished from those of other regions, and individual vertebree have special 
characters which are more or less clearly recognizable. All typical vertebr have 
_ 1 As might be expected from the history of anatomy, a good many of these terms are more or 
less interchangeable; furthermore, a given skeletal feature may differ greatly in various species. 
