Muscles that act on the Pollex (thumb): unit 1
Extensor Retinaculum
(dorsal carpal ligament, or posterior annular ligament). thickened part of the antebrachial fascia that holds the tendons of the extensor muscles in place. It is located on the back of the forearm, just proximal to the hand. It is continuous with the palmar carpal ligament, which is located on the anterior side of the forearm. It is a strong, fibrous band, extending obliquely downward and medialward across the back of the wrist, and consisting of part of the deep fascia of the back of the forearm, strengthened by the addition of some transverse fibers. is attached laterally to the lateral margin of the radius. However, it is not attached to the ulna, as the distance between these two bones varies with supination and pronation of the forearm. Instead the medial attachment is to the most medial of the carpal bones, the triquetrum (or triquetral bone) and pisiformis
Flexor Retinaculum
(transverse carpal ligament, or anterior annular ligament) is a fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones of the hands, covering them and forming the carpal tunnel. is a strong, fibrous band that covers the carpal bones on the palmar side of the hand near the wrist. It attaches to the bones near the radius and ulna. on ulnar side it attaches to the pisiform bone and the hook of the hamate bone. On the radial side, it attaches to the tubercle of the scaphoid bone, and to the medial part of the palmar surface and the ridge of the trapezium bone.
1. Flexor Pollicis Longus 2. interosseous membrane (forearm). radius: shaft anterior. 3. phalanx distal I. 4. flexes distal phalanx of thumb 5. branch of median nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 309)
1. Abductor Pollicis Longus 2. interosseous membrane: forearm. radius: shaft posterior. ulna: shaft posterior. 3. carpal:trapezium. metacarpal I. 4. abducts and extends thumb 5. radial nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 311)
1. Extensor Pollicis Brevis 2. interosseous membrane:forearm. radius: shaft posterior. 3. phalanx: proximal I 4. extends thumb 5. radial nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 311)
1. Extensor Pollicis Longus 2. interosseous membrane (forearm). Ulna: shaft posterior. 3. Phalanx: distal I 4. extends thumb 5. radial (post interosseous nerve) (only the tendon is visible)
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 311)
1. Abductor Pollicis Brevis 2. carpal: scaphoid. carpal:trapezium. flexor retinaculum. 3. phalanx: proximal I 4. abducts thumb at carpometacarpal joint 5. median nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 312)
1. Adductor Pollicis 2. carpal:capitate. Metacarpal II-IV. 3. phalanx: proximal I 4. adducts and helps to oppose thumb 5. ulnar nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 312)
1. Flexor Pollicis Brevis 2. carpal: trapezium. flexor retinaculum. 3. phalanx: proximal I. 4. flexes thumb. at carpometacarpal and metacarpophalangeal joints 5. median (or occasionally ulnar nerve)
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 312)
1. Opponens Pollicis 2. carpal: trapezium. flexor retinaculum. 3. metacarpal I 4. opposition: moves thumb to touch tip of little finger 5. median (occasionally ulnar) nerve
1. Name 2. Origin 3. Insertion 4. Function 5. Nerve (pg 312)
Palmar Aponeurosis
extension of palmaris longus muscle. invests the muscles of the palm, and consists of central, lateral, and medial portions. goes to each finger except thumb.
