Anatomy of the hand IN 14 QUESTIONS Kaan Yücel M.D., Ph.D 27.March.2014 Thursday

1. ...bones of the hand ?

2. What are flexor retinaculum & carpal tunnel? The carpal tunnel formed anteriorly at wrist by a deep arch formed by carpal bones & flexor retinaculum (transverse carpal ligament) Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus Median nerve Pass through the carpal tunnel

2. What are flexor retinaculum & carpal tunnel? The carpal tunnel formed anteriorly at wrist by a deep arch formed by carpal bones & flexor retinaculum (transverse carpal ligament) Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus Median nerve (anterior to tendons) Pass through the carpal tunnel

2. What are flexor retinaculum & carpal tunnel? The carpal tunnel formed anteriorly at wrist by a deep arch formed by carpal bones & flexor retinaculum (transverse carpal ligament) Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus Median nerve (anterior to tendons) Pass through the carpal tunnel

BONES OF THE HAND Carpal arch The carpal bones do not lie in a flat plane; rather, they form an arch, whose base is directed anteriorly. lateral side of this base formed by tubercles of the scaphoid and trapezium. medial side formed by pisiform & hook of hamate. head base

3. What is extensor retinaculum (dorsal carpal ligament)? The extensor tendons pass into the hand in six compartments defined by an extensor retinaculum: extensor digitorum & extensor indicis posterior surface of the wrist extensor carpi ulnaris & extensor digiti minimi medial side of the wrist abductor pollicis longus & extensor pollicis brevis extensor carpi radialis longus & extensor carpi radialis brevis extensor pollicis longus through three compartments on the lateral surface of the wrist.

4. What is palmar aponeurosis? A triangular condensation of deep fascia that covers the palm and is anchored to the skin in distal regions. Continuous with the palmaris longus tendon, when present; otherwise, anchored to the flexor retinaculum.

5. …Fibrous digital sheaths? Tendons of flexor digitorum superficialis and profundus cross the palm enter fibrous sheaths on the palmar aspect of the digits. formed by fibrous arches and cruciate (cross-shaped) ligaments hold the tendons to the bony plane prevent the tendons from bowing when the digits are flexed. are surrounded by a synovial

6. What are extensor hoods for? Tendons of the extensor digitorum extensor pollicis longus muscles expand over the proximal phalanges to form "extensor hoods" or "dorsal digital expansions". Tendons of the extensor digiti minimi, extensor indicis, extensor pollicis brevis join these hoods.

7. Which are the intrinsic muscles of the hand? Palmaris brevis Thenar muscles Abductor pollicis brevis Abductor digiti minimi Hypothenar muscles Opponens pollicis Adductor pollicis Flexor digiti minimi Flexor pollicis brevis Lumbrical Interossei

8. …functions the intrinsic muscles of the hand? Palmar interossei adduct the thumb, index, ring, and little fingers with respect to a long axis through the middle finger Dorsal interossei major abductors of the index, middle, and ring fingers, at the metacarpophalangeal joints

Lumbricals 8. …functions the intrinsic muscles of the hand? flexing metacarpophalangeal joints extending interphalangeal joints medial two deep branch of the ulnar nerve lateral two median nerve

Palmaris brevis 8. …functions the intrinsic muscles of the hand? deepens cup of the palm by pulling on skin over the hypothenar eminence forming a distinct ridge. This may improve grip.

9. How are the intrinsic muscles innervated? All of the intrinsic muscles of the hand by deep branch of the ulnar nerve Except three thenar & two lateral lumbrical muscles by median nerve

Superficial palmar arch 10. ....arteries of the hand? Superficial palmar arch Deep palmar arch palmar digital artery common palmar digital arteries princeps pollicis artery radialis indicis artery • three palmar metacarpal arteries •three perforating branches

Before penetrating the back of the hand, the radial artery gives rise to two vessels: dorsal carpal branch passes medially as the dorsal carpal arch, across the wrist dorsal metacarpal arteries dorsal digital arteries first dorsal metacarpal artery supplies adjacent sides of the index finger and thumb.

11....veins of the hand? Cephalic vein originates from lateral side of dorsal venous network. Basilic vein originates from medial side of dorsal venous network.

12. ...sensory innervation of the hand? Ulnar nerve medial side of the palm, medial half of the dorsum of the hand, 5th finger, medial half of the 4th finger, anterior surfaces of medial ½ digits Median nerve palmar surfaces of the lateral 3 ½ digits and cutaneous regions over the dorsal aspects of the distal phalanges (nail beds) of the same digits Radial nerve dorsolateral aspect of the palm, dorsal aspects of the lateral three,one-half digits distally to approximately the terminal interphalangeal joints

12. Median nerve

12. Ulnar nerve

12. Radial nerve

base of the carpal arch formed 13. ...carpal tunnel? base of the carpal arch formed medially by pisiform & hook of hamate laterally by tubercles of scaphoid & trapezium SLTP TTCH

14. ....anatomical snuffbox? lateral border tendons of abductor pollicis longus APLEPB extensor pollicis brevis medial border tendon of extensor pollicis longus

14. ....anatomical snuffbox? floor scaphoid & trapezium distal ends of the tendons of extensor carpi radialis longus extensor carpi radialis brevis