Anatomy: Posterior Forearm + Dorsum of Hand Flashcards
Observe that the flexor tendons of the hand have their origin on the ______ side , while the extensor tendons have their origin on the _______ side.
Flexors – medial, ulnar
Extensors – lateral, radial
a thickening of the antebrachial fascia in the distal forearm that binds down the extensor tendons as they pass onto the dorsum of the hand
extensor retinaculum
The superficial branch of the radial nerve passes from below the _______ muscle and over the ________ to supply cutaneous innervation to the dorsum of the hand.
The superficial branch of the radial nerve passes from below the brachioradialis muscle and over the extensor retinaculum to supply cutaneous innervation to the dorsum of the hand.
Sensory
What muscles does Radial nerve innervate in the hand?
NONE
The anatomical snuff box is located between the tendon of the ______ and the closely associated tendons of the _____ and _______. The ___________ passes through the anatomical snuff box.
The anatomical snuff box is located between the tendon of the EPL and the closely associated tendons of the EPB and APL. The radial artery passes through the anatomical snuff box.
The ABL takes origin from the proximal halves of the _____, _____ and ______, and attaches distally to the base of the ________.
The ABL takes origin from the proximal halves of the radius, ulna and interosseous membrane, and attaches distally to the base of the first metacarpal.
The EPB takes origin from the _________ and _____, and attaches distally to the ____________.
The EPB takes origin from the posterior distal third of the ulna and adjacent interosseous membrane, and attaches distally to the base of the proximal phalanx of the thumb.
The EPL takes origin from the ____________ and _____________, and attaches distally to the ______________.
The EPL takes origin from the posterior middle third of the ulna and adjacent interosseous membrane, and attaches distally to the base of the distal phalanx of the thumb.
The _____ takes origin from the lateral supracondylar ridge distal to the origin of the brachioradialis and inserts distally into the 2nd metacarpal.
The ECRL takes origin from the lateral supracondylar ridge distal to the origin of the brachioradialis and inserts distally into the 2nd metacarpal.
Extensor carpi radialis longus
The ______ takes origin from the lateral epicondyle (common extensor origin) and inserts distally into the 3rd metacarpal.
The ECRB takes origin from the lateral epicondyle (common extensor origin) and inserts distally into the 3rd metacarpal.
Extensor carpi radialis brevis
The _________ takes origin from the common extensor area (lateral epicondyle) and inserts into the extensor hood or expansion of the medial four fingers.
Extensor digitorum
The Extensor digitorum function
It primarily extends the fingers at the MP joint.
The _________ takes origin from the common extensor origin and inserts into the extensor expansion of the 5th finger.
The EDM takes origin from the common extensor origin and inserts into the extensor expansion of the 5th finger.
extensor digiti minimi
The ________ takes origin from the lateral epicondyle and posterior border of the ulna, and inserts into the dorsal side of the base of the 5th metacarpal. It extends and adducts the hand.
The ECU takes origin from the lateral epicondyle and posterior border of the ulna, and inserts into the dorsal side of the base of the 5th metacarpal. It extends and adducts the hand.
Extensor carpi ulnaris
The ______ takes origin from the distal third of the ulna and adjacent interosseous membrane, and inserts into the extensor expansion of the 2nd finger.
The extensor indicis takes origin from the distal third of the ulna and adjacent interosseous membrane, and inserts into the extensor expansion of the 2nd finger.
The ________ takes origin from the lateral epicondyle, posterior ulna, and adjacent ligaments associated with the radius, and inserts on the posterior lateral and anterior surfaces of the proximal radius.
Function?
The supinator muscle takes origin from the lateral epicondyle, posterior ulna, and adjacent ligaments associated with the radius, and inserts on the posterior lateral and anterior surfaces of the proximal radius.
It supinates the forearm and hand.
Superficial group of extensors of forearm
Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris
Deep Group of forearm extensors
Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis Supinator
Outcropping muscles
Outcropping muscles are the APL and EPB.
The ________ is a continuation of the deep branch of the ______ nerve and supplies all of the extensor muscles in the forearm.
The posterior interosseous nerve is a continuation of the deep branch of the radial nerve and supplies all of the extensor muscles in the forearm.
The Posterior Interosseous artery is a branch of the ________
Ulnar artery from anterior side
Carpal bones
S - Scaphoid L - Lunate T - Triquetrum P - Pisiform H - Hamate C - Capitate T - Trapezoid T - Trapezium
The four dorsal interossei are all _________ of the digits (DABs) – they ______ the 2nd, 3rd and 4th.
abductors!
The ________ insert into the base of the proximal phalanx and the extensor hood.
The dorsal interossei insert into the base of the proximal phalanx and the extensor hood.
All interossei muscles are innvervated by the ___________ nerve.
Ulnar
extensor hood includes the insertion of the _____, ______, and ______.
Extensor hood includes the insertion of the extensor tendons of the digits, the lumbricales, and the interossei muscles (anterior and posterior)
The tendon of the _____________ splits over the proximal phalanx, with a middle component going to insert on the base of the middle phalanx, and two lateral component going laterally around the PIP joint and coming back together to insert into the base of the distal phalanx.
The tendon of the extensor digitorum splits over the proximal phalanx, with a middle component going to insert on the base of the middle phalanx, and two lateral component going laterally around the PIP joint and coming back together to insert into the base of the distal phalanx.
Both the Lumbricals and the Interossei ______ the MP joint and ______ the distal phalanges
Both the Lumbricals and the Interossei flex the MP joint and extend the distal phalanges
The ________ insert into the proximal phalanx of the digit and into the extensor hood
The interossei insert into the proximal phalanx of the digit and into the extensor hood
__________ of the elbow attaches the radius to the humerus and is continuous with the ___________ that encircles the head of the radius
radial collateral ligament of the elbow attaches the radius to the humerus and is continuous with the anular ligament that encircles the head of the radius
The __________ of the elbow is located on the medial side of the elbow and attaches _______ to the humerus.
The ulnar collateral ligament of the elbow is located on the medial side of the elbow and attaches the ulna to the humerus
Median nerve palsy (proximal)
Atrophy of thenar eminence (recurrent branch of median nerve)
Thumb is laterally rotated and adducted (unopposed action of radial/ulnar nerves)
Loss of thumb flexion (flexor pollicis longus)
Loss of flexion at 2nd and 3rd PIP joints (FDS)
Loss of flexion at 2nd and 3rd DIP joints (FDP)
Weakened flexion of 2nd and 3rd MP joints (1st and 2nd lumbricals)
Median Nerve Injury (distal)
Paresthesia in the lateral three and a half fingers , No loss or abnormal sensation in the palm of the hand
Loss of coordination and strength in the thumb - weakness of thenar muscles
Difficulty in utilizing the thumb in gripping things
Weakened flexion of 2nd and 3rd MP joints - 1st and 2nd lumbricals
Phalen test positive - compression of median nerve in carpal tunnel
Phalen test
compression of the median nerve in the carpal tunnel produces abnormal sensations in the lateral three and one-half digits
Atrophy of thenar eminence
Thumb is laterally rotated and adducted
Loss of thumb flexion
Loss of flexion at 2nd and 3rd PIP joints
Loss of flexion at 2nd and 3rd DIP joints
Weakened flexion of 2nd and 3rd MP joints
Median Nerve Palsy (proximal)
Paresthesia in the lateral three and a half fingers
No loss or abnormal sensation in the palm of the hand
Loss of coordination and strength in the thumb
Difficulty in utilizing the thumb in gripping things
Weakened flexion of 2nd and 3rd MP joints
Median Nerve Injury (distal)
Loss of flexion at 4th and 5th DIP joints
Loss of flexion at 4th and 5th MP joint (hyperextension of joint)
Inability to extend the IP joints when attempting to straighten the fingers
Hypoesthesia and paresthesia in little finger and ulnar half of ring finger
Atrophy of the interossei muscles
Weakness of thumb adduction
Radial deviation of hand
Ulnar nerve palsy (proximal)
Ulnar Nerve Palsy (proximal)
Loss of flexion at 4th and 5th DIP joints - FDP
Loss of flexion at 4th and 5th MP joint (hyperextension of joint) - 3rd/4th lumbricals
Inability to extend the IP joints when attempting to straighten the fingers - 3rd/4th lumbricals/interossei
Hypoesthesia and paresthesia in little finger and ulnar half of ring finger
Atrophy of the interossei muscles
Weakness of thumb adduction - adductor pollicis
Radial deviation of hand (d/t no competition from flexor carpi ulnaris)
No loss of flexion at 4th and 5th DIP joints
Loss of flexion at 4th and 5th MP joint (hyperextension of joint)
Inability to extend the IP joints when attempting to straighten the fingers
Hypoesthesia and paresthesia in little finger and ulnar half of ring finger
Atrophy of the interossei muscles
Weakness of thumb adduction
Ability to flex unaffected; no radial deviation of hand
Ulnar nerve palsy (distal)
Ulnar nerve palsy (distal)
No loss of flexion at 4th and 5th DIP joints (FDP ok)
Loss of flexion at 4th and 5th MP joint (hyperextension of joint) (3rd/4th lumbricals)
Inability to extend the IP joints when attempting to straighten the fingers (3rd/4th lumbricals/interossei)
Hypoesthesia and paresthesia in little finger and ulnar half of ring finger
Atrophy of the interossei muscles
Weakness of thumb adduction - adductor pollicis
Ability to flex unaffected; no radial deviation of hand
Radial Nerve injury
Inability to extend the wrist and fingers at the MP joint
Wrist partially flexed
If higher up - triceps atrophy
Inability to extend the wrist and fingers at the MP joint
Wrist partially flexed
Radial nerve injury
