Forearm Flashcards
(38 cards)
radius
- head location
- articulates with
- other important landmarks
head located proximally in discoid shaped
articulates with capitulum and radial notch of ulna
neck
radial tuberosity
medial facing sharpened edge on body
-attachment of interosseus membrane
anterior and posterior oblique lines
ulnar notch; distal radioulnar joint
styloid process; articulation with carpal bones
dorsal tubercle
ulna
-important landmarks
olecranon coronoid process -lateral side has a radial notch -supinator fossa and supinator crest -tuberosity on anterior surface for insertion of brachialis trochlear notch lateral sharpened interosseus border head (distal) -styloid process -convex articular surface laterally for articulation with radius
functions of pronator quadratus and pronator teres in pronation
quadratus
-prime mover
-responsible for initiation
-can act as only pronator during slow unopposed pronation
teres
-increases strength and speed of pronation
radial and ulnar deviation of the hand and wrist require…
pair of muscles radial deviation -flexor carpi radialis -extensor carpi radialis longus -extensor carpi radialis brevis ulnar deviation -flexor carpi ulnaris -extensor carpi ulnaris
lateral epicondyle relation to muscles
common extensor origin of a large number of superficial muscles of posterior surface of forearm
primary movers of supination
biceps brachii is a strong supinator used in forceful movements
supinator is prime mover in non-forceful situations
interosseus membrane
-function
anchors the radius ulna together
serves as an origin for some of the muscles of the forearm
relative strength of radius and ulna’s articulation with humerus
-why is one stronger?
ulna has stronger articulation -olecranon -coronoid process -trochlear notch -all 3 form a strong hinge-type joint radius -articulation with capitulum is only anchored by annular ring surrounding head of radius
distal articulation of forearm
-formed by
radius articulating with
- scaphoid
- lunate
- maybe triquetral and triquetrum
styloid processes (radius and ulna) length comparison
radius styloid process extends more distally
colles fracture
- what is it?
- most common mechanism of injury (MOI)
- how will it present?
- what else may be damaged
what -fracture of styloid process of radius -displacement of styloid process proximally MOI -falling on outstretched hand (forearm extended) presentation -styloid processes at same level may also damage scaphoid bone
ulnar nerve
- path at the distal humerus
- level of protection
swings around the medial epicondyle of the humerus
relative unprotected
nerves of the forearm
median
ulnar
radial
median nerve
-function
innervates all muscles of the anterior (flexor) compartment except
-brachioradialis
-flexor carpi ulmaris
-medial part of flexor digitorum profundus
carries sensory components to the skin of the forearm, hand, elbow, and wrist joints
brachioradialis
- innervation
- functions
- usually listed as occupying what compartment
- -why?
radial nerve
flexor of forearm at the elbow
usually listed as occupying the posterior compartment of the forearm
-due to origin near the common origin of the extensors of the forearm
flexor carpi ulnaris and medial part of flexor digitorum profundus
-innervation
ulnar nerve
anterior interosseus nerve
- what is it?
- function
what
-named muscular branch of the median nerve
-arises near apex of cubital fossa
-courses along anterior surface of the interosseus membrane
innervates
-other 1/2 of flexor digitorum profundus (digits 2, 3)
-flexor pollicis longus
-pronator quadratus
palmar cutaneous branch of median nerve
articular branches of the wrist
ulnar nerve
-location from elbow to wrist
posterior to medial epicondyle
deep to flexor carpi ulnaris along flexor digitorum profundus
medial to ulnar artery
ulnar nerve function
articular branches to elbow muscular branches to -flexor carpi ulnaris -flexor digitorum profundus palmar cutaneous branch to -medial 1/2 of palmar surface of hand (little and ring finger) dorsal cutaneous branch to -medial 1/2 of dorsal surface of hand (little and ring finger)
radial nerve
- enters forearm…
- branches into…
enters on
-anterior side of lateral epicondyle between brachialis and brachioradialis
branches into superficial and deep branch
radial nerve superficial branch
-function
entirely cutaneous skin of -dorsum of wrist -hand -thumb -dorsum of digits 2,3
radial nerve deep branch
- function
- location
entirely muscular and articular innervates -supinator -extensor carpi radialis brevis sweeps around lateral side of radius to extensor compartment
posterior interosseus nerve of radial nerve
- function
- location
innervates
-muscles of the deep extensor compartment
travels with posterior interosseus artery (branch of ulnar artery)
