Anatomy: Posterior Forearm + Dorsum of Hand

Question 1

Observe that the flexor tendons of the hand have their origin on the ______ side , while the extensor tendons have their origin on the _______ side.

Answer 1

Flexors – medial, ulnar

Extensors – lateral, radial

Question 2

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

Answer 2

extensor retinaculum

Question 3

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.

Answer 3

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

Question 4

What muscles does Radial nerve innervate in the hand?

Answer 4

NONE

Question 5

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.

Answer 5

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.

Question 6

The ABL takes origin from the proximal halves of the _____, _____ and ______, and attaches distally to the base of the ________.

Answer 6

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.

Question 7

The EPB takes origin from the _________ and _____, and attaches distally to the ____________.

Answer 7

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.

Question 8

The EPL takes origin from the ____________ and _____________, and attaches distally to the ______________.

Answer 8

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.

Question 9

The _____ takes origin from the lateral supracondylar ridge distal to the origin of the brachioradialis and inserts distally into the 2nd metacarpal.

Answer 9

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

Question 10

The ______ takes origin from the lateral epicondyle (common extensor origin) and inserts distally into the 3rd metacarpal.

Answer 10

The ECRB takes origin from the lateral epicondyle (common extensor origin) and inserts distally into the 3rd metacarpal.

Extensor carpi radialis brevis

Question 11

The _________ takes origin from the common extensor area (lateral epicondyle) and inserts into the extensor hood or expansion of the medial four fingers.

Answer 11

Extensor digitorum

Question 12

The Extensor digitorum function

Answer 12

It primarily extends the fingers at the MP joint.

Question 13

The _________ takes origin from the common extensor origin and inserts into the extensor expansion of the 5th finger.

Answer 13

The EDM takes origin from the common extensor origin and inserts into the extensor expansion of the 5th finger.

extensor digiti minimi

Question 14

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.

Answer 14

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

Question 15

The ______ takes origin from the distal third of the ulna and adjacent interosseous membrane, and inserts into the extensor expansion of the 2nd finger.

Answer 15

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.

Question 16

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?

Answer 16

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.

Question 17

Superficial group of extensors of forearm

Answer 17

Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris

Question 18

Deep Group of forearm extensors

Answer 18

Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis
Supinator

Question 19

Outcropping muscles

Answer 19

Outcropping muscles are the APL and EPB.

Question 20

The ________ is a continuation of the deep branch of the ______ nerve and supplies all of the extensor muscles in the forearm.

Answer 20

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.

Question 21

The Posterior Interosseous artery is a branch of the ________

Answer 21

Ulnar artery from anterior side

Question 22

Carpal bones

Answer 22

S - Scaphoid
L - Lunate
T - Triquetrum
P - Pisiform
H - Hamate
C - Capitate
T - Trapezoid 
T - Trapezium

Question 23

The four dorsal interossei are all _________ of the digits (DABs) – they ______ the 2nd, 3rd and 4th.

Answer 23

abductors!

Question 24

The ________ insert into the base of the proximal phalanx and the extensor hood.

Answer 24

The dorsal interossei insert into the base of the proximal phalanx and the extensor hood.

Question 25

All interossei muscles are innvervated by the ___________ nerve.

Answer 25

Ulnar

Question 26

extensor hood includes the insertion of the _____, ______, and ______.

Answer 26

Extensor hood includes the insertion of the extensor tendons of the digits, the lumbricales, and the interossei muscles (anterior and posterior)

Question 27

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.

Answer 27

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.

Question 28

Both the Lumbricals and the Interossei ______ the MP joint and ______ the distal phalanges

Answer 28

Both the Lumbricals and the Interossei flex the MP joint and extend the distal phalanges

Question 29

The ________ insert into the proximal phalanx of the digit and into the extensor hood

Answer 29

The interossei insert into the proximal phalanx of the digit and into the extensor hood

Question 30

__________ of the elbow attaches the radius to the humerus and is continuous with the ___________ that encircles the head of the radius

Answer 30

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

Question 31

The __________ of the elbow is located on the medial side of the elbow and attaches _______ to the humerus.

Answer 31

The ulnar collateral ligament of the elbow is located on the medial side of the elbow and attaches the ulna to the humerus

Question 32

Median nerve palsy (proximal)

Answer 32

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)

Question 33

Median Nerve Injury (distal)

Answer 33

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

Question 34

Phalen test

Answer 34

compression of the median nerve in the carpal tunnel produces abnormal sensations in the lateral three and one-half digits

Question 35

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

Answer 35

Median Nerve Palsy (proximal)

Question 36

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

Answer 36

Median Nerve Injury (distal)

Question 37

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

Answer 37

Ulnar nerve palsy (proximal)

Question 38

Ulnar Nerve Palsy (proximal)

Answer 38

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)

Question 39

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

Answer 39

Ulnar nerve palsy (distal)

Question 40

Ulnar nerve palsy (distal)

Answer 40

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

Question 41

Radial Nerve injury

Answer 41

Inability to extend the wrist and fingers at the MP joint

Wrist partially flexed

If higher up - triceps atrophy

Question 42

Inability to extend the wrist and fingers at the MP joint

Wrist partially flexed

Answer 42

Radial nerve injury