Hand Anatomy: Osteology, Joints & Ligaments

• The hand is part of the upper limb and human anatomy.

Hand Osteology

• The hand consists of phalanges (phalanx), metacarpals (MC1-5), and carpals.
• The ulna and radius are also part of the hand's skeletal structure.
• The scaphoid and lunate are carpal bones.

Hand Joints

• The hand includes distal interphalangeal (DIP) joints.
• The hand includes proximal interphalangeal (PIP) joints.
• The hand includes metacarpophalangeal (MCP) joints.
• Also included are the carpometacarpal (CMC) joints of the 5th digit and thumb.
• The thumb contains an interphalangeal (IP) joint and a carpometacarpal joint (CMC).
• Other joints of the hand are intercarpal joints, the radiocarpal joint, and the distal radio-ulnar joint.
• The midcarpal joint is also part of the hand's anatomy.
• The wrist joint consists of the carpals, scaphoid, lunate, radius, ulna, and metacarpals.

Wrist Ligaments

• Ligaments support the wrist in both palmar and dorsal views.

Flexor Retinaculum & Carpal Tunnel

• The flexor retinaculum is a key structure in the wrist.
• The carpal tunnel and ulnar tunnel are also important.

Forearm Tendons & Arterial Blood Flow

• Tendons of forearm muscles extend into the hand.
• The brachial artery branches into radial and ulnar arteries.
• There are also radial recurrent arteries and anterior ulnar recurrent arteries
• The common interosseous artery is vital for blood supply.
• Arterial blood flow from the forearm consists of the common interosseous artery, ulnar artery, and radial artery.
• Arterial blood flow to the palm is supplied via the superficial palmar arch.
• Additionally the deep palmar arch, ulnar artery, and radial artery contribute.

Forearm Nerves

• Nerves including the radial, median, and ulnar nerves proceed into the hand.

Arteries, Nerves, and Tendons in the Palm

• Structures entering the palm include the superficial palmar arch, ulnar nerve, ulnar artery, median nerve, flexor retinaculum, and radial artery.
• The carpal tunnel contains carpal bones.
• The carpal tunnel consists of the ulnar nerve and artery in the ulnar tunnel, flexor digitorum superficialis tendons, flexor digitorum profundus tendons, flexor pollicis longus tendon, flexor carpi radialis tendon and the median nerve.
• Tendon sheaths and ligaments are present at the wrist.
• The flexor retinaculum and flexor tendon sheaths are key components.

Intrinsic Palm Muscles

• The palmaris brevis muscle, palmar aponeurosis, flexor retinaculum, and palmaris longus tendon are parts of the superficial layer of intrinsic palm muscles.
• The flexor carpi ulnaris tendon (to MC5) is another muscle in the superficial layer.
• Other superficial intrinsic palm muscles are the flexor digitorum superficialis tendons, flexor digiti minimi brevis, abductor digiti minimi, flexor pollicis brevis, and abductor pollicis brevis.
• The middle layer includes the lumbrical muscles, adductor pollicis, flexor pollicis longus tendon, and opponens pollicis, along with the opponens digiti minimi and flexor digiti minimi brevis
• Muscles gets named for the action they perform.

Lumbrical Muscles Action

• The lumbrical muscles flex the metacarpophalangeal joint.
• The lumbrical help extendinterphalangeal joints.
• “Even out" also describes the speed at which fingers are flexed.

Nerves of the Palm

• The ulnar and median nerves run through the palm.
• The ulnar nerve is associated with all digiti minimi muscles and the medial lumbricals, palmaris brevis, and adductor pollicis.
• Conversely, the median nerve is linked to most pollicis muscles, the lateral lumbricals.

Cutaneous Innervation (Dermatomes)

• Cutaneous innervation includes the end of axillary nerve, lateral antebrachial cutaneous nerve (end of musculocutaneous nerve), median nerve, ulnar nerve, and radial nerve.

Forearm Compartments

• The posterior forearm compartment contains muscles such as the brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, and extensor carpi ulnaris.
• the extensor digiti minimi is also represented.
• Additionally, it contains the triceps brachii muscle, superior ulnar collateral artery, ulnar nerve, medial epicondyle, olecranon of ulna, and anconeus muscle
• The radial artery and extensor retinaculum muscles appear as well
• Ulnar, medial, and lateral nerves and muscles are here, including the supinator, extensor pollicis longus and brevis, abductor pollicus longus etc.

Dorsal Muscles

• Interossei muscles: ABDUCT & ADDUCT MIDDLE THREE DIGITS + ADDUCT pinky.

Tendons in Dorsum of Hand

• The dorsum of the hand features the extensor indicis tendon, extensor pollicis longus and brevis tendons, abductor pollicis longus tendon, extensor digitorum tendon, extensor digiti minimi tendon, and extensor retinaculum.
• The anatomical snuffbox contains the extensor pollicis longus and brevis tendons.
• Also the abductor pollicis longus tendon, the 1st dorsal interosseous, and the radial artery.

Actions of Certain Muscle Groups on the Fingers

• Anterior muscles: 8+15 = 23, including flexor, palmaris and pronator
• Posterior muscles: 10+4 = 14, including extensor, supinator and abductor.
• Interosseous palmar muscles 3.
• Interosseous dorsal muscles 4.
• Lumbricals muscles 4.
• For the thumb, abduction is performed by the abductor pollicis longus/brevis, adduction by the adductor pollicis, and opposition by the opponens pollicis. For the digits, abduction, adduction and opposition is performed by the interossei muscle. For the pinky, abduction is performed by the abductor digiti minimi and opposition by the opponens digiti minimi

Superficial Veins

• Superficial veins include the dorsal venous plexus, cephalic vein, and basilic vein.
• Superficial veins of the anterior upper limb include the cephalic and basilic veins.
• The median cubital vein also appears
• Other superficial veins include; apical axillary lymph nodes, deltopectoral lymph nodes, pectoralis minor muscle, central axillary lymph nodes, axillary vein, and humoral (lateral) auxiliary etc.
• The cephalic vein of arm, basilic vein, cubital lymph nodes, basilic vein etc are involved.

Explore the intricate anatomy of the human hand, covering the osteology of phalanges, metacarpals, and carpals. Key joints such as DIP, PIP, MCP, and CMC joints are detailed. The role of wrist ligaments and the flexor retinaculum in supporting hand structure and function are also discussed.