Primate ANT Forearm

  1. Pronator TeresImage Upload 1
    • Origin: Humerus: medial epicondyle
    • Insertion: Radius: middle 1/3 of lateral shaft
    • Nerve: Median
    • Action: Pronates forearm (its main function), flexes forearm
    • Comparative Anatomy: Humans and Apes:
    • Pronator teres has 2 heads of origin:
    •    Humeral head: already described
    •    Ulnar or deep head: arises from the medial border of the coronoid process.
  2. Image Upload 2
    Flexor Carpi Radialis
    • Origin: Humerus: medial epicondyle
    • Insertion: Metacarpal II: base
    • Nerve: Median
    • Action: Flexes hand at wrist
  3. Image Upload 3
    Palmaris Longus
    (This is the most superficial of the forearm flexors.)
    • Origin: Humerus: medial epicondyle
    • Insertion: Palmar aponeurosis
    • Nerve: Median
    • Action: Tenses palmar aponeurosis; slightly flexes hand at wrist
    • CA: Humans:Muscle may be totally absent in up to 15% of human individuals. check both arms to see if you have this muscle.
  4. Image Upload 4
    Flexor Carpi Ulnaris
    • Origin:Humeral head: humerus, medial epicondyle; Ulnar head: ulna, medial surface of olecranon process
    • Insertion: Pisiform
    • Nerve: ulnar
    • Action: Flexes hand at wrist
  5. Epitrochleoanconeus
    (this muscle occurs more frequently in lower primates and only occasionally in humans and apes)
    • Origin: Humerus: medial epichondyle
    • Insertion: Ulna:olecranon process
    • Nerve: Ulnar
    • Action: aBducts olecranon in lower animals
    • CA: Humans: Approximately 1 in 4 humans will have this small muscle which is called Epitrochleoolecranonis in human anatomy books.
  6. Image Upload 5
    Flexor digitorum superficialis
    • Origin: Humerus: medial epicondyle; Joint capsule of elbow
    • Insertion: Middle phalanges, digits II-V, ventral surfaces.
    • Nerve: Median
    • Action: Flexes middle phalanges and when acting more strongly flexes the wrist.
    • CA: In human primates and large apes, this muscle has an ulnar and radial head in addition to its humeral head.
  7. Flexor digitorum Profundus
Card Set
Primate ANT Forearm
Lab study