Muscles And Fasciae Of The Upper Limb part 3 Flashcards
SUPERFICIAL LAYER (POSTERIOR COMPARTMENT) All extend as tendons into the hand except:
- Brachioradialis
* Anconeus
BRACHIORADIALIS Origin:
proximal part of the supraepicondylar ridge of the humerus
BRACHIORADIALIS Insertion:
lateral side of the distal end of the radius just proximal to the radial styloid process
BRACHIORADIALIS Innervation::
radial nerve
BRACHIORADIALIS Origin:
accessory flexor of elbow joint
forms the lateral boundary of the cubital fossa.
BRACHIORADIALIS
EXTENSOR CARPI RADIALIS LONGUS
Origin:
o distal part of the supraepicondylar ridge
o lateral epicondyle of the humerus
EXTENSOR CARPI RADIALIS LONGUS
Insertion:
dorsal surface of the base of metacarpal II
EXTENSOR CARPI RADIALIS LONGUS
Innervation:
deep branch of the radial nerve
EXTENSOR CARPI RADIALIS LONGUS
Action:
extends and abducts the wrist
EXTENSOR CARPI RADIALIS BREVIS Origin:
lateral epicondyle of the humerus
EXTENSOR CARPI RADIALIS BREVIS Insertion:
adjacent dorsal surfaces of the bases of metacarpals II and III
EXTENSOR CARPI RADIALIS BREVIS Innervation:
deep branch of the radial nerve
EXTENSOR CARPI RADIALIS BREVIS Action:
extends and abducts the wrist
EXTENSOR DIGITORUM Origin:
lateral epicondyle of the humerus
EXTENSOR DIGITORUM Insertion:
via the triangular-shaped connective tissue aponeurosis (extensor hood) into the base of the dorsal surfaces of the middle and distal phalanges
EXTENSOR DIGITORUM Innervation:
posterior interosseous nerve
EXTENSOR DIGITORUM Action:
Major extensor of the 4 fingers (index, middle, ring, and little fingers
EXTENSOR DIGITORUM
o It results from the distal interphalangeal joint suddenly being forced into extreme flexion
o Sudden severe tension on a long extensor tendon, avulse attachment to the phalanx
o Treatment: use of finger splint to approximate the edges of the torn tendon
Mallet or baseball finger:
EXTENSOR DIGITI MINIMI Origin:
medial to extensor digitorum in the forearm arising from lateral epicondyle of the humerus
EXTENSOR DIGITI MINIMI Insertion:
together with the tendon of extensor digitorum into the dorsal digital expansion of the little finger
EXTENSOR DIGITI MINIMI Innervation:
posterior interosseous nerve
EXTENSOR DIGITI MINIMI Action:
accessory extensor of the small finger
EXTENSOR CARPI ULNARIS Location:
medial to the extensor digiti minimi
EXTENSOR CARPI ULNARIS Location:
lateral epicondyle of the humerus
EXTENSOR CARPI ULNARIS Origin:
medial
side of the base of
metacarpal V
EXTENSOR CARPI ULNARIS Insertion:
posterior interosseous nerve
EXTENSOR CARPI ULNARIS Innervation:
extends and adducts the wrist
ANCONEUS Location:
most medial
of the superficial extensors
ANCONEUS Shape:
triangular
ANCONEUS Origin:
lateral
epicondyle of the humerus
ANCONEUS Insertion:
o Posterolateral surface
of the olecranon
o Posterior surface of the ulna
ANCONEUS Innervation:
branch of the radial nerve
ANCONEUS Action:
abducts the ulna during pronation & accessory extensor of the elbow joint
5 muscles in the DEEP LAYER (POSTERIOR COMPARTMENT)
o Supinator o Abductor pollicis longus o Extensor pollicis brevis o Extensor pollicis longus o Extensor indicis
All deep layer muscles originate from the posterior surfaces of the radius, ulna, interosseous membrane, and pass into the thumb & fingers except: __
supinator muscle
3 muscles that emerge from between extensor digitorum and extensor carpi radialis brevis tendons of the superficial layer and pass into the thumb:
o Abductor pollicis longus
o Extensor pollicis brevis
o Extensor pollicis longus
2 of the three outcropping muscles that form a distinct muscular bulge in the distal posterolateral surface of the forearm:
o Abductor pollicis longus
o Extensor pollicis brevis
All muscles of the deep layer are innervated by the __ (continuation of radial nerve deep branch)
posterior interosseous nerve
SUPINATOR
Has 2 heads of origin:
o Superficial humeral head
o Deep ulnar head
SUPINATOR Insertion:
proximal aspect of radius
SUPINATOR Innervation:
posterior interosseous nerve that innervates the medial head of the triceps brachii
SUPINATOR Action:
supinates forearm
ABDUCTOR POLLICIS LONGUS Origin:
o Proximal posterior surfaces of the radius & ulna
o Interosseous membrane
ABDUCTOR POLLICIS LONGUS Insertion:
lateral side of the base of metacarpal I
ABDUCTOR POLLICIS LONGUS Innervation:
posterior interosseous nerve (C7 and C8)
ABDUCTOR POLLICIS LONGUS Action:
abduct the thumb at the joint between metacarpal I and trapezium bones
It contributes to the lateral border of the anatomical snuffbox
Abductor pollicis longus tendon
EXTENSOR POLLICIS BREVIS Origin:
distal to the origin of abductor pollicis longus from the posterior surface of the radius and interosseous membrane
EXTENSOR POLLICIS BREVIS Insertion:
dorsal surface of the base of the proximal phalanx
EXTENSOR POLLICIS BREVIS Innervation:
Posterior interosseous nerve
EXTENSOR POLLICIS BREVIS Action:
extends the MCP and carpometacarpal joints of the thumb
contributes as well to the lateral border of the anatomical snuffbox
Extensor pollicis brevis tendon
- Occurs when the tendons around the base of thumb (APL and EPB) are irritated or constricted
- Noticeable when forming a fist; grasping; gripping; turning the wrist
- Characterized by tendon swelling and causes pain and tenderness along the thumb side of the wrist
De Quervain’s Tenosynovitis
De Quervain’s Tenosynovitis
Dx: placing thumb against your hand. Making a fist with your fingers closed over your thumb and then bending wrist toward little finger
Finkelstein test
EXTENSOR POLLICIS LONGUS Origin:
posterior surface of the ulna & adjacent interosseous membrane
EXTENSOR POLLICIS LONGUS Insertion:
long tendon into the dorsal surface of distal phalanx of the thumb