Digits

Humans and carnivores are identical with 5 digits. In carnivores, they are designated DIGIT 1, DIGIT 2, DIGIT 3, DIGIT 4, and DIGIT 5 in a medial to lateral direction, respectively.

Digit 1 is distal to metacarpal 1, digit 2 is distal to metacarpal 2, and so on.

The digits are made up of individual bones called PHALANGES. A PHALANX refers to one of the bones that make up the digits and is the singular form of phalanges.

In the dog, digit 1 is analogous to your thumb and is also referred to as the POLLEX.

Digit 1 contains a PROXIMAL and DISTAL PHALANX.

The remaining 4 digits, using digit 2 as an example, contain a PROXIMAL, MIDDLE, and DISTAL PHALANX.

The proper terminology for an individual phalanx would be, for example, "MIDDLE PHALANX OF DIGIT 2".

Proximal phalanges: light green; middle phalanges: yellow; distal phalanges: light blue.


CLINICAL CORRELATION

Declawing of domestic cats-
++++A. onychectomy
++++B. partial or complete removal of the distal phalanx


Image series key:

1. RADIUS
2. ULNA
3. INTERMEDIORADIAL CARPAL BONE
4. ACCESSORY CARPAL BONE
5. ULNAR CARPAL BONE
6. FIRST CARPAL BONE
7. SECOND CARPAL BONE
8. THIRD CARPAL BONE
9. FOURTH CARPAL BONE
10. METACARPAL 1
11. METACARPAL 2**
12. METACARPAL 3**
13. METACARPAL 4**
14. METACARPAL 5**
15. PROXIMAL PHALANX OF DIGIT 1**
16. DISTAL PHALANX OF DIGIT 1**
17. PROXIMAL PHALANX OF DIGIT 2**
18. PROXIMAL PHALANX OF DIGIT 3**
19. PROXIMAL PHALANX OF DIGIT 4**
20. PROXIMAL PHALANX OF DIGIT 5**
21. MIDDLE PHALANX OF DIGIT 2**
22. MIDDLE PHALANX OF DIGIT 3**
23. MIDDLE PHALANX OF DIGIT 4**
24. MIDDLE PHALANX OF DIGIT 5**
25. DISTAL PHALANX OF DIGIT 2**
26. DISTAL PHALANX OF DIGIT 3**
27. DISTAL PHALANX OF DIGIT 4**
28. DISTAL PHALANX OF DIGIT 5**
29. PROXIMAL SESAMOID BONE
30. DORSAL SESAMOID BONE
31. SESAMOID IN ABDUCTOR DIGITI 1 LONGUS

**INDICATES PALPABLE STRUCTURE