- Skeletal system
- Head muscles
- Neck muscles
- Muscles of upper limb
- Muscles of pectoral girdle
- Muscles of shoulder region
- Muscles of upper arm
- Muscles of forearm
- Muscles of hand
- Medial group (Muscles of little finger)
- Middle group of hand muscles
- Lateral group (Muscles of thumb)
- Thoracic muscles
- Muscles of back
- Muscles of lower limb
- Blood vessels
- Respiratory system
- Digestive system
- Endocrine glands
- Nervous system
- Lymphatic system
- Female reproductive system
- Male reproductive system
Dorsal interossei of hand
The dorsal interossei (Latin: musculi interossei dorsales) are a group of short intrinsic muscles of the hand that are located in the spaces between the metacarpal bones. These four paired muscles extend between the metacarpal bones and proximal phalanges. Together with the lumbricals and palmar interossei muscles, the dorsal interossei belong to the middle group of the hand muscles.
|Dorsal interossei of hand|
|Origin||Adjacent sides of metacarpal bones 1 - 5|
|Insertion||Bases of proximal phalanges 2 - 4, extensor expansions|
Finger abduction at metacarpophalangeal joints (2nd - 4th)
Flexion of proximal phalanges at metacarpophalangeal joints (2nd - 4th)
Extension of middle and distal phalanges at interphalangeal joints (2nd - 4th)
|Innervation||Deep branch of ulnar nerve (C8 - T1)|
|Blood supply||Dorsal metacarpal arteries 1 - 4|
The dorsal interossei muscles originate from the adjacent sides of the first to fifth metacarpal bones.
The dorsal interossei insert on the bases of the second to fourth proximal phalanges and extensor expansions of the second to fourth fingers. The first and second dorsal interossei insert on the lateral (radial) sides of the proximal phalanges 2 and 3, while the third and fourth dorsal interossei attach to the medial (ulnar) sides of the proximal phalanges 3 and 4.
The primary function of the dorsal interossei muscles is to provide the finger abduction at the second to fourth metacarpophalangeal joints. Like the lumbricals of the hand, these muscles also flex the proximal phalanges at the second to fourth metacarpophalangeal joints and extend the middle and distal phalanges at the second to fourth interphalangeal joints.
The dorsal interossei of the hand are innervated by the deep branch of the ulnar nerve (C8 - Th1).
The dorsal interossei muscles receive arterial blood supply from the dorsal metacarpal arteries. The first dorsal metacarpal artery is a branch of the radial artery, while the second to fourth dorsal metacarpal arteries arise from the dorsal carpal arch.