Lab 7: Posterior Forearm and Dorsal Hand Flashcards
Dorsal Venous Arch
Origin of the cephalic and basilic veins
Extensor Retinaculum
Thickening of the antebrachial fascia in the wrist region
Identify the six superficial muscles of the posterior forearm
Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis extensor digitorium extensor minimi extensor carpi ulnaris
Which superficial posterior muscles of the forearm share the common extensor tendon
Extensor carpi radialis brevis
Extensir digitorium
Extensor digiti minimi
Extensor Carpi Ulnaris
Common extensor tendon (location and clinical relevance)
Located on the lateral epicondyle
Irritation (lateral epicondytis) = Tennis Elbow
Which superficial posterior forearm muscle is most often involved in tennis elbow
ECRB
Extensor carpi radialis brevis
Identify the five deep muscles of the posterior forearm
Supinator Abductor Pollicis Longus Extensor Pollicis brevis Extensor Pollicis Longus Extensor Indicis
Supinator Origin and Insertion
Origin: Ulnar (superior to abductor pollicis longus)
Insertion: Radial ( Superior to pronator teres)
Order of attachment (proximal to distal) of deep muscles of posterior forearm on the ulna
- Supinator
- APL (Abductor Pollicis Longus)
- EPL (Extensor Pollicis Longus)
- EI (Extensor Indicis)
Which of the deep muscles of the posterior forearm does not contact the ulna
- EPB (Extensor Pollicis Brevis)
Nerve that comes through the Supinator
- Deep Radial nerve enters the supinator, as it exits it is named the posterior interosseous nerve
Posterior Interosseous nerve
Continuation of Deep Radial Nerve
Emerges from Supinator
Runs along pollicis muscles
Travels with Posterior Interosseous Artery
Anterior Border of anatomical snuff box
Tendon of the extensor pollicis brevis
Indirect:
Tendon of abductor pollicis longus
Posterior Border of anatomical snuff box
Tendon of the extensor Pollisis Longus
Describe the course of neurovasculature in/around the anatomical snuff box
Radial Artery runs through the snuff box
Cephalic vein courses over the top
** think about anatomical position (Cephalic closer to
head)
What forms the floor of the snuff box?
Scaphoid Bone
Trapezium
1st Metacarpal
Dorsal Interossei muscles
“DAB”
- 4 muscles that act on 3 fingers to ABduct them away from finger 3 (midline)
- Feather/Leaf appearance
First Dorsal Interossei Muscle
From Metacarpal 1 to Metacarpal 2
Connects to radial side of 2 @ extensor expansion
Second Dorsal Interossei Muscle
From Metacarpal 2 to 3
Connects radial side of 3 @ extensor expansion
Third Dorsal Interossei Muscle
From Metacarpal 3 to 4
Connects ulnar side of 4 @ extensor Expansion
Fourth Dorsal Interossei Muscle
From Metacarpal 4 to 5
Connects ulnar side of 5 @ extensor expansion
Course of the extensor expansion and impact of joint movement
On palmar side of MP joint (Flexion)
On Dorsal Side of PIP and DIP joints (Extension)
***All about how it crosses the joint
Tendons of extensor digitorum
Extensor digitor gives off 4 tendons that are covered by the exensor expansion (hood) as of comes up from the palmar side
Metacarpals 2-5 (NOTE: No thumb)
Action: extends the wrist and all four fingers
Extensor Expansion (most distal)
Present on dorsum of digits 2-5
Distal attachment of lumbercals and interossi muscles
Action of the exetnsor expansion
Simultaneously flex the metacarpophalangeal joints
*** think about how it crosses these joints
Attachment of Extensor carpi radialis longs
base of metacarpal 1
Attachment of Extensor carbi radialis brevis
base of metacarpal 2
Attachment of Extensor carpi ularis
base of metacarpal 5
Name the extensor carpi muscles (in order from superior to inferior - anatomical position)
Extensor carpi radialis longus (2)
Extensor carpi radialis brevis (3)
Extensor carpi ulnaris (5)
