This section describes the hands and their structures.

Hand Anatomy

Bones

• Three main groups
  • Carpals
    • 8 bones in 2 rows of 4
  • Metacarpals
    • 5 bones
      • First metacarpal
        • shortest, most mobile, and constitutes the thumb
      • 4 metacarpals
        • heads form the knuckles and articulate with the proximal phanlanges
      • Phalanges
        • 14 total
          • 3 each finger and 2 in the thumb

http://www.rad.washington.edu/RadAnat/HandPALabelled.html

Muscles and Tendons

• Intrinsic- originate in the hand

• General

  • Delicate finger movements

  • Location- Palmer side of hand

• Lumbricals- 4- index to the 5th finger

  • Nerve Innervation-

    • index and middle finger- Median Nerve

    • ring finger and 5th finger- Ulnar Nerve

    • flexion of MCP joints

    • extension of the interphalangeal joints

• Interossei- innervated by the Ulnar nerve

  • Palmar- Adduction of the fingers to the ring finger

  • Dorsal- Abduction of the finger

• Thenar (pollicis)-Thumb side

  • Abductor- Median Nerve- Abduction of the thumb

  • Flexor- Median Nerve- Flexes thumb

  • Opponens- Median Nerve- opposes thumb and 4 fingers

  • Adductor- Ulnar Nerve- adduction of the thumb

• Hypothenar (digiti minimi)- Ulnar side of the hand (5th finger)

  • Abductor- Ulnar Nerve- Abducts 5th finger at the MCP joint

  • Flexor- Ulnar Nerve- Flexes 5th finger at the MCP joint

  • Opponens- Ulnar Nerve- opposes 5th finger with the other fingers

• Extrinsic- originate in the forearm

  • Wrist flexors and extensors

    • Stabilize the wrist in slight dorsiflexion

  • Finger flexors

    • Deep flexors- 5- flex distal phalanges of the fingers and thumb

    • Superficial flexors- 4- flex middle phalanges of the fingers

    • Course flexors- under the Annular ligaments (Pulleys) and between distal palmer crease and IP joint

  • Finger extensors

    • Course dorsal over fingers and thumb

    • Extend proximal phalanges

Nerves

	1.Abductor pollicis brevis 2.Flexor pollicis brevis 3.Oblique head of adductor pollicis 4.Transverse head of adductor pollicis 5.Flexor digiti minimi brevis 6.Abductor digiti minimi 7.Superficial palmar arch 8.Common palmar digital branches
	1. 1st lumbrical 2. 2nd lumbrical 3. 3rd lumbrical 4. 4th lumbrical 5. Adductor pollicis 6. Flexor pollicis brevis 7. Tendon of flexor pollicis longus 8. Tendons of flexor digitorum profundus 9. Tendon of flexor digitorum superficialis (cut) 10. Fibrous flexor sheath
	1. Ulnar nerve-C8 – Innervates all hand intrinsic muscles except Lumbricals & Thenar muscles. Provides sensation to the 5th finger and half the ring finger & motor to the Hypothenar muscles13; 2.Median nerve -C7- Innervates/motor to the Thenar muscles and the radial Lumbricals. Provides sensation to the Palmer surfaces and side of the thumb, index, middle, and half ring finger 3.Radial nerve-C6- Does not innervate intrinsic muscles. Innervates the extrinsic wrist and finger extensors. Provides sensation to the dorsolateral 2/3rds and the dorsal surfaces of the thumb, index, middle, and radial half of the ring fingers
http://anatomy.uams.edu/htmlpages/ anatomyhtml/hand

Blood Supply

• Arteries
  • Radial- Branches
    • Dorsal carpal artery- supplies the dorsal surface and fingers
    • Palmar
      • Superficial-forms the superficial arch
      • Deep- arch forms the 4 palmar metacarpal arteries and supplies the fingers
  • Ulnar – Branches
    • forms the deep and superficial palmer arches with the radial
• Veins
  • Venous plexus
  • Dorsal venous network
    • drains proximally into the lateral cephalic and medial basilic veins

	1. Radial artery 2 .Arteria princeps pollicis 3. 1st dorsal metacarpal a. 4. 2nd dorsal metacarpal a. 5. 3rd dorsal metacarpal a. 6. 4th dorsal metacarpal a. 7. Dorsal digital artery to 5th digit 8. Dorsal carpal branch of ulnar artery 9. Dorsal carpal branch of radial artery 10. Anastomoses between anterior and posterior interosseious arteries
http://anatomy.uams.edu/htmlpages/ anatomyhtml/hand

Basic Study Questions

  1.  What digit number is the ring finger, the thumb, and the index finger?

  2.  What are the 3 main groups of bones in the hand?

  3.  What 3 nerves supply innervation to the hand? 

Additiional Study Questions