Unit 16: Posterior Forearm and Hand
supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
From a posterior view, name the deep muscles of post forearm from lat --> medial:
brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, anconeus
From a posterior view, name the superficial muscles of post forearm from lat --> medial:
dorsal digital arteries
G?
recurrent interosseous artery
G?
Anconeus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris (which also attaches to posterior border of ulna), supinator (also radial colalteral and anular ligaments, supinator fossa and crest of ulna)
What has its origin at the lateral epicondyle of the humerus?
Supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis
What muscles make up the deep layer of the posterior forearm?
Brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, anconeus
What muscles make up the superficial layer of the forearm?
Abductor pollicis longus
A?
Posterior interosseous
A?
deep artery of arm (profunda brachii)
A?
abducts the thumb at carpometacarpal joint
Abductor pollicis longus: action
posterior interosseus artery (a branch of ulnar artery)
Abductor pollicis longus: blood supply
posterior interosseous nerve (C7, C8), a branch of the radial nerve
Abductor pollicis longus: innervation
lateral supracondylar ridge of the humerus
Brachioradialis: origin
Trapezium, scaphoid, radial artery, cephalic vein
Contents of the anatomical snuff box:
deep radial n. passes through the supinator m.; some authors believe that the posterior interosseous n. and the deep radial n. are synonymous, others say that when the deep radial n. emerges from the supinator in the posterior forearm it becomes the posterior interosseous n.,
Course of deep radial nerve?
Extensor digiti minimi
G?
dorsal branches of proper palmar digital arteries
H?
Extensor carpi radialis brevis (C7,C8), and Supinator (C5,C6)
Innervations of the deep radial nerve?
anterior interosseous artery
L?
supinates the forearm
Supinator: action
posterior interosseous nerve (C7, C8), a branch of the radial nerve
Extensor pollicis longus: innervation
radial recurrent artery
Brachioradialis: blood supply
radial nerve (C5,6,7)
Brachioradialis: innervation
lateral surface of distal end of radius
Brachioradialis: insertion
1st compartment post to ext. pol. brevis, insert on the radial side of the base of the first metacarpal
Abductor pollicis longus: insertion
middle one-third of the posterior surface of the radius, interosseous membrane, mid-portion of posterolateral ulna
Abductor pollicis longus: origin
extends the forearm assists in dynamic stabilization of elbow joint
Anconeus: action
interosseous recurrent artery
Anconeus: blood supply
radial nerve (C7, C8, and T1)
Anconeus: innervation
lateral surface of olecranon and superior part of post. surface of ulna
Anconeus: insertion
lateral epicondyle of humerus
Anconeus: origin
Extensor pollicis brevis
B?
anterior interosseous
B?
superior ulnar collateral artery
B?
posterior border - tendon of the extensor pollicis longus anterior border - tendons of extensor pollicis brevis and the abductor pollicis longus proximal border - styloid process of the radius
Boundaries of the anatomical snuff box?
flexes forearm
Brachioradialis: action
Extensor carpi radialis longus
C?
dorsal carpal branch of ulnar artery
C?
inferior ulnar collateral artery
C?
passes through third compartment, uses dorsal radial tubercle (Lister's) as pivot point to change direction, and inserts on base of distal phalanx of thumb
Extensor pollicis longus: insertion ALSO COURSE?
interosseous membrane and middle part of the posterolateral surface of the ulna
Extensor pollicis longus: origin
Extensor digitorum
F?
brachial artery (in cubital fossa)
F?
dorsal metacarpal arteries
F?
posterior interosseus artery (a branch of ulnar artery)
Extensor indicis: blood supply
posterior interosseous nerve (C7, C8), a branch of the radial nerve
Extensor indicis: innervation
passes through fourth compartment to insert on extensor hood of index finger
Extensor indicis: insertion
interosseous membrane and the posterolateral surface of the distal ulna
Extensor indicis: origin
extends the thumb at the metacarpophalangeal joint
Extensor pollicis brevis: action
posterior interosseus artery (a branch of ulnar artery)
Extensor pollicis brevis: blood supply
posterior interosseous nerve (C7, C8), a branch of the radial nerve
Extensor pollicis brevis: innervation
It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. descends on the interosseous membrane, in front of the Extensor pollicis longus, to the back of the carpus,
Course of posterior interosseous nerve?
1st compartment ant to abductor pol. longus, inserts on proximal phalanx of the thumb
Extensor pollicis brevis: insertion
interosseous membrane and the posterior surface of the distal radius
Extensor pollicis brevis: origin
extends the thumb at the interphalangeal joint
Extensor pollicis longus: action
Extensor carpi radialis brevis
D?
dorsal carpal arch
D?
radial collateral artery
D?
posterior interosseus artery (a branch of ulnar artery)
Extensor pollicis longus: blood supply
Extensor pollicis longus
E?
middle collateral artery
E?
perforating branches
E?
extends the wrist; abducts the hand
Extensor carpi radialis brevis: action
radial artery
Extensor carpi radialis brevis: blood supply
deep radial nerve (C7,8)
Extensor carpi radialis brevis: innervation
2nd compartment (medial) base of the third metacarpal bone (base)
Extensor carpi radialis brevis: insertion
common extensor tendon (lateral epicondyle of humerus)
Extensor carpi radialis brevis: origin
Extend and abduct hand at wrist
Extensor carpi radialis longus: action
Radial artery
Extensor carpi radialis longus: blood supply
radial nerve (C6,7)
Extensor carpi radialis longus: innervation
passes through second compartment under extensor retinaculum to insert on the base of 2nd metacarpal
Extensor carpi radialis longus: insertion
Lateral supraepicondylar ridge of humerus
Extensor carpi radialis longus: origin
Extends and also adducts hand at wrist joint
Extensor carpi ulnaris: action
Ulnar artery
Extensor carpi ulnaris: blood supply
posterior interosseous nerve (C7,8), a branch of the radial nerve. The deep radial branch of the radial artery becomes the posterior interosseous nerve.
Extensor carpi ulnaris: innervation
Passes through sixth compartment under the extensor retinaculum to insert on the base of the fifth metacarpal
Extensor carpi ulnaris: insertion
1. Common extensor tendon (lateral epicondyl of humerus. 2. Posterior border of ulna
Extensor carpi ulnaris: origin
extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 5th digit
Extensor digiti minimi: action
interosseous recurrent a.
Extensor digiti minimi: blood supply
posterior interosseous nerve (C7,8), a branch of the radial nerve. The deep radial branch of the radial artery becomes the posterior interosseous nerve.
Extensor digiti minimi: innervation
(5th compartment) joins the extensor digitorum tendon to the 5th digit and inserts into the extensor expansion.
Extensor digiti minimi: insertion
common extensor tendon (lateral epicondyle of the humerus)
Extensor digiti minimi: origin
extends medial four digits at metacarpophalangeal joints, extends hand at wrist joint
Extensor digitorum: action
interosseous recurrent a. and posterior interosseous a.
Extensor digitorum: blood supply
posterior interosseous nerve (C7,8), a branch of the radial nerve
Extensor digitorum: innervation
passes through fourth compartment under extensor retinaculum to insert as the extensor hood on middle and distal phalanges of digits 2-5, but sometimes not 5
Extensor digitorum: insertion
common extensor tendon (lateral epicondyle of the humerus)
Extensor digitorum: origin
extends the index finger at the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints
Extensor indicis: action
Extensor carpi ulnaris
H?
radial recurrent artery
H?
Extensor indicis
I?
anterior ulnar recurrent
I?
dorsalis indicis
I?
Anconeus (C7,C8,T1), extensor carpi radialis longus(C6,C7), brachioradialis (C5,C6,C7).
Innervations of the main trunk of the radial nerve?
posterior ulnar recurrent
J?
radial artery
J?
common interosseous artery (branch of ulnar artery)
K?
dorsalis pollicis
K?
radial artery
M?
ulnar artery
N?
posterior interosseous artery
O?
recurrent interosseous artery (branch of posterior interosseous artery, a branch of ulnar artery)
Supinator: blood supply
deep radial nerve (C5, C6)
Supinator: innervation
lateral, posterior, and anterior surfaces of proximal third of radius
Supinator: insertion
lateral epicondyle of the humerus, supinator crest & fossa of the ulna, radial collateral and anular ligaments
Supinator: origin
Divides into superficial and deep radial nerves at the anterior of the elbow. superficial goes to skin, deep enters supinator muscle Superficial radial nerve - purely cutaneous to posterior forearm and hand. Deep radial nerve - supplies extensor carpi radialis brevis (C7,C8) and supinator (C5,C6). Once the deep radial nerve crosses supinator, it becomes the posterior interosseous nerve. This nerve supplies all other muscles of the posterior forearm.
Where does the radial nerve divide? Names its divisions & continuations, and innervations of those divisions?
