2 INTRODUCTION 



clature. This system was first adopted by the German Anatomical Society at a 

 meeting in Basel, in 1895, and is hence called the Basel Nomina Anatomica, or 

 briefly, the BNA. The BNA provides each term in Latin form, which is es- 

 pecially desirable for international usage. Each nation, however, is expected to 

 translate the terms into its own language, wherever it is deemed preferable for 

 everyday usage. Thus in the present work the Anglicised form of the BNA is 

 generally used. Where not identical, however, the Latin form is added once for 

 each term in a place convenient for reference, and is designated by enclosure in 

 brackets [ ]. Where necessary the older terms have also been added as synonyms. 



The Commission by whom the BNA was prepared included eminent anatomists represent- 

 ing various European nations. The work of the Commission was very thorough and careful, 

 and extended through a period of six years. Among the guiding principles in the difficult task 

 of selecting the most suitable terms were the following: (1) Each part should have one name 

 only. (2) The names should be as short and simple as possible. (3) Related structures 

 should have similar names. (4) Adjectives should be in opposing pairs. A few exceptions 

 were found necessary, however. 



On account of its obvious merits, the BNA system has been generally adopted throughout 

 the civihsed world, and the results are very satisfactory. Comparatively few new terms have 

 been thereby introduced, over 4000 of the 4500 names in the BNA corresponding almost exactly 

 to older terms already in use by the English-speaking nations. Certain minor defects in the 

 system have been criticised; but these are outweighed by the advantages of this uniform 

 system. 



Abbreviations. — Certain frequently used words in the BNA are abbreviated as follows: 

 a., arteria (plural, aa., arteriae); b., bursa; g., ganglion; gl., glandula; lig., ligamentum (plural, 

 ligg., hgamenta); m., musculus (plural, mm., musculi); n., nervus (plural, nn., nervi); oss., 

 ossis (or ossium); proc, processus; r., ramus (plural, rr., rami); v., vena (plural, vv., vense). 



Terms of position and direction. — The exact meaning of certain fundamental 

 terms used in anatomical description must be clearly understood and kept in 

 mind. In defining these terms, it is supposed that the human body is in an 

 upright position, with arms at the sides and palms to the front. 



The three fundamental planes of the body are the sagittal, the transverse and 

 the frontal. The vertical plane through the longitudinal axis of the trunk, 

 dividing the body into right and left halves, is the median or mid-sagittal plane; 

 and any plane parallel to this is a sagittal plane. Any vertical plane at right 

 angles to a sagittal plane, and dividing the body into front and rear portions is a 

 frontal (or coronal) plane. A plane across the body at right angles to sagittal and 

 coronal planes is a transverse or horizontal plane. 



Terms pertaining to the front of the body are anterior or ventral) to the rear, 

 posterior or dorsal; upper is designated as superior or cranial; and lower as inferior 

 or caudal. 



The term medial means nearer the mid-sagittal plane, and lateral, further from 

 that plane. These terms should be carefully distinguished from internal (inner) 

 and external (outer), which were formerly synonymous with them. Internal, as 

 now used (BNA), means deeper, i. e., nearer the central axis of the body or part; 

 while external refers to structures more superficial in position. Proximal, in 

 describing a limb, refers to position nearer the trunk; while distal refers to a more 

 peripheral position. 



'Adverbial forms are also employed, e. g., anteriorly or ventrally (forward, before); poster- 

 iorly or dorsally (backward, behind) ; superiorly or cranially (upward, above) ; and inferiorly or 

 caudally (downward, below). 



It should also be noted that the terms ventral, dorsal, cranial and caudal are independent of 

 the body posture, and therefore apply equally well to corresponding surfaces of vertebrates in 

 general with horizontal body axis. On this account these terms are preferable, and will doubt- 

 less ultimately supplant the terms anterior, posterior, superior and inferior. 



The discrimination in the use of several similar terms of the BNA should also receive atten- 

 tion. Thus medianus (median) refers to the median plane. Medialis (medial) means nearer 

 the median plane and is opposed to lateral, as above stated. Medms (middle) is used to desig- 

 nate a position between anterior and posterior, or between internal and external. Between 

 medialis and lateralis, however, the term irdcrmedms is used. I'inally, transversalis means trans- 

 verse to the body axis; Iransversus, transverse to an organ or part; and transversarius, pertaining 

 to some other structure which is transverse. 



Parts of the body. — Tlic primary divisions of the human body (fig. 1) are the 

 head, neck, trunk and extremities. The head [caput] includes cranium and /ace 

 [facies]. The neck [collum] connects head and trunk. The trunk [truncus] 

 includes thorax, abdomen, and pelvis. The upper extremity [extremitas superior] 

 includes arm [brachium], forearm [antibrachium], and hand [manus]. The 



I 



