Forearm/Hand anatomy Flashcards
medial boundary of cubital fossa
Mass of medial flexor muslces arising from common flexor attachement on medial epicondyle - mainly pronator teres
lateral boundary of cubital fossa
mass of extensor forearm muscles from lateral epicondyle - mainly brachioradialis
Floor of cubital fossa
brachialis and supinator
Roof of cubital fossa
The continuity of the brachial and antebrachial deep fascia - reinforced by the bicipital aponeurosis, subcutaneous tissue and skin
Contents of cubital fossa
Brachial artery lying between the biceps tendon and the median nerve. The beginning of the radial and ulnar arteries.
Deep accompanying veins of the arteries.
Biceps brachii tendon.
Median nerve.
Radial nerve - deep between brachioradialis and brachialis - it divides into its superficial and deep branches here.
Superficial cubital fossa
Median cubital vein.
Cephalic and Basilic veins.
Median and lateral cutaneous nerves of forearm.
Superficial flexor/pronator muscles
Pronator teres, FCR, PL, FLU. The superficial muscles cross the elbow joint.
Intermediate layer of flexor/pronator muscles
FDS, Does cross the elbow joint
Deep layer of flexor/pronator muscles
FDP, FPL, Pronator quadratus. The deep muscles do not cross the elbow joint.
How is brachioradialis a mojor exception to the rule?
It is a flexor of the forearm but is located in the posteriolateral extensor compartment and it is supplied by the radial nerve.
The long flexors of the digits; FDP and FDS also flex which joints?
MCPJs and wrist
FDS attaches to ___ and flexes ___ joints.
Middle phalanges and PIPJs
FDP attaches to ___ and flexes ___ joints
Distal phalanges and DIPJs
The most lateral superficial forearm flexor
PT
FRC’s distal course and attachment
Passes through a canal in the lateral part of the flexor retinaculum and through a vertical groove in the trapezium in its own synovial tendinous sheath of the FCR
radial arter lies ____ to FCR
Lateral
PL is absent in ___ % of people
14% usually on the left side
ulnar nerve relation to FCU
Ulnar nerve enters the forearm by passing between the humeral and ulnar heads of proximal FCU
FCU innervation
Ulnar nerve
Relationship of ulnar nerve and artery to FCU tendon
Ulnar nerve and artery lie lateral to FCU tendon at wrist
FDS is the largest superficial flexor of forearm True or False
True
Which nerve and artery passes between the proximal attachments of the FDS.
Median nerve and Ulnar artery
What are the two proximal attachements of FDS?
Radial head and humeroulnar head
How many and which tendons are enclosed in the common flexor sheath?
4 tendons from FDS and 4 from FDP
Can FDS flex each finger independently?
Yes
Where is the neurovascular plane in the anterior forearm?
It is the fascial plane that lies between the intermediate and deep layers of muscle.
The only muscle able to flex the DIPJs is….
FDP
The tendons of FDP are ___ to the tendons of FDS in the Carpal Tunnel
Posterior
Which DIPJs are able to be flexed independently
Only the index finger DIPj due to the part of FDP supplying this digit branching off from the rest of FDP early in the forearm. c/w FDS which can flex all the PIPjs independently.
FPL muslce lies ___ to FDP in the forearm. And distal to the ____ muscle
Lateral to FDP and distal to Supinator
FPL overlies the ___ bone in the forearm while FDP overlies the ___ bone
FPL - radius. FDP - ulnar
The FPL tendon course in the wrist….
Passes through the carpal tunnel enclosed in its own tendinous sheath
What landmarks demarcate the anterior and posterior compartments of the forearm
The radial artery laterally and the sharp, subcutaneous posterior boarder of the ulnar medially
The structures that pass through the carpal tunnel are…
9 tendons - FPL, 4 from FDP and 4 from FDS
1 nerve - median nerve
the FPL tendon pass through the carpal tunnel on the ___ side of the FDS and FDP tendons
Lateral
Which is the only muscle able to flex the IPJ of the thumb
FPL - median n
The deepest muscle in the anterior forearm is…
Pronator Quadratus
The muscle that is most important for pronation is ___ due to its role in initiating the movment
Pronator Quadratus. Pronator Teres assists when more speed and power is required.
Structures holding the radius and ulnar together distally during force transmitted through the wrist…
interosseus membrane. Pronator Quadratus
The common flexor attachment is…
Medical epicondyle and supracondylar ridge of humerus.
Muscles that extend and abduct or adduct the hand at the wrist joint (Extensor group 1)
ECRL, ECRB, ECU
Muscles that extend the medial 4 fingers (Extensor group 2)
Extensor Digitorum, Extensor Indicies, Extensor digiti minimi
Muscles that extend or abduct the thumb (Extensor group 3)
Abductor Pollicus Longus
Extensor Pollicus Brevis
Extensor Pollicus Longus
The extensor tendons are held in place at the wrist by ….
the extensor retinaculum.