Flexors and Extensors of the Antebrachium Flashcards
Extensor carpi radialis m.
O: Lateral supracondylar crest of humerus (2 heads in the cat)
I: Dorsal surface of base of metacarpals II and II (long tendon on MC II and short tendon on MC III in cats)
N: Radial n.
A: Extend carpus
Common digital extensor m.
O: Lateral epicondyle of humerus
I: Extensor process of distal phalanx of digits 2-5
N: Radial n.
A: Extend carpus, extend metacarpophalangeal joints of digits 2-5
Lateral digital extensor m.
O: Dog - lateral epicondyle of humerus; Cat - lateral supracondylar ridge of humerus
I: Extensor process of distal (and middle) phalanx of digits 3-5 in the dog and digits 2-5 in cats
N: Radial n.
A: Extend carpus, extend metacarpophalangeal and interphalangeal joints of digits 3-5 in dog; 2-5 in cat
Extensor carpi ulnaris m. (ulnaris lateralis)
O: Lateral epicondyle of humerus
I: Dog - lateral aspect of proximal end of metacarpal V and accessory carpal bone; Cat - metacarpal V
N: Radial n.
A: Abduct the carpus and support the carpus when extended to support weight
Long abductor of digit 1 (abductor policis longus, extensor carpi obliquus)
O: Lateral border and cranial surface of body of ulna, the interosseous membrane (arises from radius in cats)
I: Proximal end of metacarpal I
N: Radial n.
A: Abduct digit I and extend carpus
Supinator m.
O: Lateral epicondyle of humerus
I: Cranial surface of the proximal fourth of the radius
N: Radial n.
A: Rotate forearm laterally so that palmar side of paw faces medially (supination) and flex elbow
Brachioradialis m.
O: Dog - lateral supracondylar crest of humerus; Cat - middle fifth of humerus
I: Dog - distal fourth of radius; Cat - styloid process of radius
N: Radial n.
A: Rotate radius dorsolaterally (supinate)
Flexor carpi radialis m.
O: Medial epicondyle of humerus and medial border of radius
I: Palmar side of base of metacarpals II and III
N: Median n.
A: Flex carpus
Superficial digital flexor m.
O: Medial epicondyle of humerus
I: Palmar surface of PII of digits 2-5
N: Median n.
A: Flex carpus, flex metacarpophalangeal and proximal interphalangeal joints of digits 2-5
Flexor carpi ulnaris m.
O: Ulnar head - caudal border and medial surface of olecranon; Humeral head - medial epicondyle of humerus
I: Accessory carpal bone
N: Ulnar n.
A: Flex carpus
Deep digital flexor m.
O: Humeral head - medial epicondyle of humerus; Ulnar head - proximal 3/4’s of caudal border of ulna; Radial head - middle third of medial bone of radius
I: Palmar surface of P III of digits 1-5
N: Median and ulnar nn.
A: Flex carpus; flex metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of digits 1-5
Pronator teres m.
O: Medial epicondyle of humerus
I: Medial border of the radius between proximal and middle thirds
N: Median n.
A: Rotate forearm medially so that palmar side of paw faces the ground (pronation) and flex elbow
Pronator quadratus m.
O: Ulnar surface apposed to radius
I: Radial surface apposed to ulna
N: Median n.
A: Pronate forepaw
Interossei m.
O: Proximal metacarpals II-V and joint capsule of carpus
I: Proximal sesamoid bones, base of proximal P I, common digital extensor tendon
N: Ulnar n.
A: Flex metacarpophalangeal joints 2-5
Flexor manica
Sleeve that covers the SDF and the DDF on the palmar aspect of the carpus, prevents displacement of those muscles when stepping with paw
