Interossei muscles (hand)
The interossei muscles ( Latin for " interosseous muscles ") are a group of skeletal muscles in the metacarpal area , but a corresponding group of interossei muscles also occurs on the foot .
Dorsal interossei muscles
| Musculi interossei dorsales manus 1 to 4 |
|---|
|
| origin |
| Facing sides of adjacent metacarpals |
| approach |
| Radiation into the dorsal aponeurosis |
| function |
| Flexion in the metacarpophalangeal joints, extension in the interphalangeal joints, and abduction of the fingers |
| Innervation |
| Ulnar nerve , profund branch |
| Spinal segments |
| C8, Th1 |
The interossei dorsales muscles of the hand spread the fingers apart, bend the metacarpophalangeal joints and straighten the finger joints. The overlying tendons of the finger extensors all belong to muscles that are innervated by the radial nerve. If there is a lesion of the ulnar nerve , deep pits can be observed between these tendons on the back of the hand. These pits are caused by the no longer present innervation and the subsequent atrophy of the dorsal interossei muscles and are an important diagnostic feature for damage to the ulnar nerve even with a relaxed hand, in contrast to the claw hand , which only occurs when the muscles are tensed.
Palmar interossei muscles
| Palmar interossei muscles 1 to 3 |
|---|
|
| origin |
| Ulnar side of the os metacarpi II (musculus interosseus palmaris 1) Radial side of the IV and V metacarpus (palmar intersossei muscles 2 and 3) |
| approach |
| Radiation into the dorsal aponeurosis of fingers II, IV and V |
| function |
| Adduction of fingers II, IV and V to the middle finger, flexion in the metacarpophalangeal joints and extension in the finger joints |
| Innervation |
| Ulnar nerve , profund branch |
| Spinal segments |
| C8, Th1 |
Since the interosseus palmaris tertius muscle attaches to the little finger , there is no separate adductor digiti minimi muscle in humans. The opposite is true of the thumb , which has no interosseus palmaris muscle, but a separate adductor pollicis muscle .
literature
- K.-P. Valerius et al .: The Muscle Book . 7th ext. Edition. Hippocrates, 2014, ISBN 978-3-86867-239-8 .