Hand
The hand (manus) is the distal part of the upper limb, a unique tool that allows a person to perform the finest manipulations. The hand contains 27 bones, 34 muscles (of which 18 are your own), dozens of tendons and ligaments.
Skeleton brush
The bones of the hand are divided into three sections:
Wrist - 8 short bones arranged in two rows:
- Proximal: scaphoid, lunate, triquetral, pisiform
- Distal: trapezoid, trapezoidal, capitate, uncinate
Pastern - 5 tubular bones that form the palm.
Phalanges - 3 in each finger (proximal, middle, distal), except for the big one - it has 2 phalanges. There are 14 phalanges in total.
Joints
Radiocarpal joint - connects the radius to the proximal row of the wrist. Elliptical, allows flexion, extension, abduction and adduction.
Carpometacarpal joint of the first finger is a saddle joint that provides opposition to the thumb. This movement is a key evolutionary acquisition for humans.
Metcarpophalangeal joints are spherical and allow flexion, extension and abduction of the fingers.
Muscles
Thenar muscles (eminence of the thumb):
- Flexor brevis, opponensus, abductors, adductors
Hypothenar muscles (eminence of the little finger):
- Abductor, flexor brevis, opponator
Vermiform muscles (4) - flex the metacarpophalangeal and extend the interphalangeal joints.
Interosseous muscles (7) - abduction and adduction of the fingers.
Most powerful movements of the hand are performed by the muscles of the forearm through the long flexor and extensor tendons passing through the carpal tunnel and under the retinaculum.
Innervation
Three nerves innervate the hand:
- Median nerve - thenar, 3.5 fingers on the palmar side. Compression in the carpal tunnel → carpal tunnel syndrome
- Ulnar nerve - hypothenar, interosseous, 1.5 fingers
- Radial nerve - dorsum of the hand (sensitivity)
Blood supply
The radial and ulnar arteries form the superficial and deep arterial arches in the palm, providing reliable blood supply to all fingers.
Hand anatomy is one of the most complex areas, requiring in-depth knowledge for tendon, nerve and finger replantation surgery.
All 27 bones, joints and tendons of the hand can be viewed in detail in 3D atlas Humio - rotate, scale and study each structure.