• Thoracic Limb
  • Thoracic girdle
  • Arm
  • Forearm
    • Radius
    • Ulna
  • Forepaw
• Pelvic Limb
  • Pelvic girdle
  • Thigh
  • Leg
    • Tibia
    • Fibula
  • Hindpaw
• Vertebral Column
  • Vertebrae
  • Ribs
  • Sternum
• Skull
  • Introduction
  • Braincase
  • Facial bones
  • Cavities of skull
  • Quizzes

 

Thoracic Limb

Forepaw

Carpal bones: The carpal bones are seven, small, irregular bones arranged into two rows. The proximal row contains the large intermedioradial carpal, the lateral ulnar carpal and the palmar accessory carpal bones. The distal row includes from medial to lateral, four bones, the first, second and fourth carpal bones .

Metacarpal Bones: The metacarpus consists of fives bones.   They are likened to miniature long bones, possessing a slender body, or shaft, and large extremities.  The proximal extremity is the base, and the distal one is the head.  These bones are numbered (I, II, III, IV, V) from medial to lateral. The first metacarpal is atypical and vestigial.

Phalanges: There are three phalanges (proximal, middle, distal) for each digits, except the first digit (Pollex), which has only two phalanges. Found on the distal phalanx is  a tubercle which projects proximally from the palmar border of the base, this projection is the insertion of the deep digital flexor.  The ungual crest is a thin shelf of bone that overlaps the claw and forming a band that surrounds the root of the claw.  The rounded dorsal part of the base is the extensor process, on which the common digital extensor tendon is inserted.  The ungual process is a curved extension of the distal phalanx into the claw.