Forearm

Question 1

What are the boundaries of the cubital fossa?

Answer 1

CF: a trianglular area between the pronator teres, brachioradialis, and a line joining the humeral epicondyles. Floor: brachialis & supinator muscle Roof: bicipital aponeurosis & deep fascia of forearm

Question 2

What are the contents of the cubital fossa?

Answer 2

-Brachial artery, vein & median n (lie media to biceps tendon) -Lateral cutaneous n. (lie lateral to the biceps tendon) -Radia n. dividing into deep & superficial radial ns. Lie deep to the brachialis.

Question 3

What structures contact the roof of the CF but not technically within it?

Answer 3

Cephalic vein Median cubital bein Basillic vein

Question 4

Extrinsic vs Intrinsic muscles of the hand (definitions)

Answer 4

-Extrinsic-those that arise on the forearm and insert into the fingers. For strength/power/grip -Intrinsic-those that arise within the hand (bones) for fine movement and precision

Question 5

Prime movers for: -Ulnar deviation (adduction) -Radial deviation (abduction)

Answer 5

Adduction: Flexor and extensr carpi ulnaris Abduction: Flexor + extensor carpi radialis and snuffbox muscles

Question 6

Muscles of the superficial flexor compartment of the forearm

Answer 6

-Pronator teres (two heads:origin on the medial epicondyle, one from the coronoid process of the ulna) -Fexor carpi radialis (medial epicondyle –> base of 2nd metacarpal) -Palmaris longus (medial epicondyle –> ligament that spread across the palm) -Flexor carpi ulnaris (medial epicondyle –> the ulnar side of the hand -at base-ish)

Question 7

Muscles of the intermediate flexor group

Answer 7

One muscle-Flexor digitorum superficialis, kind of rectangle shape-originates from the medial epicondyle, the proximal ulna and attach to the base of the phalangial of all but the thumb -this compartment also contains the median n that runs under the flexor digitorum superficialis. Also has the ulnar nerve that runs deep to the FDS.

Question 8

Muscles of the deep flexor group

Answer 8

-Flexor pollicis longus-ant surface of radius & interosseous membrane –> base of distal phalanx of thumb -Flexor digitorum profundus - ant ulna & interosseous membrane –> distal phalanges 4 digits -Pronator quadratus - distal 1/4 ulna –> distal 1/4 radius -Median n. also runs through here but at the cubital fossa area it gives off the anterior interosseus branch that run along the surface of the interosseus membrane. -Ulnar n. runs on the surface of the flexor digitorum profundus

Question 9

What is the prime mover of flexion at the interphalangeal (IP) joints?

Answer 9

Flexor digitorum superficial (FDS) and flexor digitorum profundus (FDP). FDP attaches to the distal phalanx and is the only one that flexes the DIP joint.

Question 10

Innervation of the flexor compartment

Answer 10

Median nerve innervates all except flexor carpi ulnaris and the ulnar two tendons of the flexor digitorum profundus (tendons to the ring and small finger)

Question 11

Anterior interosseus nerve

Answer 11

Branch of the median nerve. Supplies most of the deep muscles of forearm flexors (except for the two tendons of the flexor digitorum profundus. In other words, it supplies the pronator quadratus, flexor pollicis longus, and radial two tendons of the flexor digitorum profundus.

Question 12

Extensor compartment:

Mobile Wad (muscles that pass along the radial border)

Answer 12

Brachioradialis

Extensor carpi radialis longus

Extensor carpi radialis brevis

Question 13

Extensor compartment:

Long extensors (muscles that pass along the posterior surface of the forearm)

Answer 13

Extensor digitorum communis

Extensor digiti minimi (quinti)

Extensor carpi ulnaris

Question 14

How do you test for damage to the anterior interosseus nerve?

Answer 14

This innervates muscles that allows you to make an O with the thumb and index finger. FDP and FPL (flexor pollicis longus)

Question 15

What are the muscles of the mobile wad?

Answer 15

(muscles that pass along the radial border)

Brachioradialis

Extensor carpi radialis longus

Extensor carpi radialis brevis

Question 16

What are the long extensors of the forearm?

Answer 16

These are muscles that pass along the posterior surface of the forearm

Extensor digitorum communis

Extensor digiti minimi (quinti)

Extensor carpi ulnaris

Question 17

What are the short extensors of the forearm?

Answer 17

Called short because they arise not from the lateral epicondyle but rather from the radius, interosseus membrane and ulna. These muscles have no actions at the elbows but serves the thumb and forefinger.

Three for the thumb:

Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicis longus

and one for the forefinger: Extensor indicis proprius

Question 18

What are the other two extensors of the forearm?

Answer 18

Aconeus and supinator muscle

Question 19

Outline the path of the radial nerve

Answer 19

After leaving the extensor compartment of the arm (where it innervates the triceps), the radial nerve dives into the extensor compartment of the forearm where it innervates the mobile wad (brachioradialis, extensor carpi radialis longus, and extensor carpo radialis brevis) before giving off two branches:

1. Deep radial nerver-innervates the rest of the muscles
2. Superficial radial nerve - does not innervate muscles but supplies cutaneous innervation to much of the radial side of the dorsum of the hand

Question 20

Answer 20

Left to Right

Pronator teres

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

Question 21

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

Answer 25

Question 26

Answer 26

Question 27

Answer 27

Question 28

Answer 28

Question 29

Answer 29

Question 30

What are the attachment points for the retinaculum forming the carpal tunnel?

Answer 30

Pisiform and hook of hamate on the ulnar side Tubercles of scaphoid and trapezium on the radial side

Question 31

What goes through the carpal tunnel?

Answer 31

4 tendons of the flexor digitorum superficialis 4 tendons of the flexor digitorum profundus Tendon of the flexor pollicis longus The median nerve (not the palmar branch because that originates in the forearm)

Question 32

What structures in the forearm do NOT go through the carpal tunnel?

Answer 32

Ulnar n Radial and ulnar artery wrist flexor muscles Flexor carpi radialis looks like it goes through but it has its own compartment

Question 33

Muscles in the thenar group What innervates them

Answer 33

Opponens pollicis Flexor pollicis brevis Abductor pollicis brevis The thenar group is innervated by recurrent branch of median n

Question 34

Muscles of the hypothenar group What innervates them

Answer 34

Opponens digiti minimi Flexor digiti minimi brevis Abductor digiti minimi All muscles in the hand except the thenar group and first two lumbricals are innervaed by ulnar n.

Question 35

Muscles of the central group (of the hand)

Answer 35

Adductor pollicis Lumbricals Interosseus (palmar & dorsal)

Question 36

Cutaneous innervation of the hand

Answer 36

Medial, radial and ulnar n. Ulnar covers the pinky + ulnar half of the ring finger on both dorsal and palmar side Median covers the thumb through radial half of ring finger on the palmar side Radial covers thumb through radial half of finger on the dorsal side Innervations to the palms usually arise in the forear, so injuries at the wrist wont affect them. Only sensation in the digits will be affected. Carpal tunnel-radial half or so of the palm is spared

Question 37

Innervation of the hand muscles

Answer 37

All of the hand muscles are innervated by the ulnar n. except the thenar muscles and the first two lumbricals. Those are inervated by the recurrent branch of median n. Another exception is the deep head of the flexor pollicis brevis is innervated by the ulnar n. So in the end, the ulnar nerve divides into two branches, the deep one supplies hypothenar, interossei, ulnar two lumbricals and the deep head of flexor pollicis brevis

Question 38

Motion of the finger joints: Flexion at MCP PIP DIP

Answer 38

MCP-lumbricals and interossei PIP-flextor digitorum superficialis DIP-flexor digitorum profundus

Question 39

Motion at the finger joint: Extension at MCP PIP DIP

Answer 39

MCP: extensor digitorum communis PIP: central slip of lumbricals and interossei DIP: terminal slip of lumbricals and interossei

Question 40

Motion at finger joint: Abduction at MCP joint Adduction of MCP joint

Answer 40

Dorsal interossei (ab) Palmar interossei (add)

Question 41

Motion of the thumb joint Flexion at CMC MCP IP

Answer 41

CMC-none MCP-Flexor pollicis brevis IP-Flexor pollicis longus

Question 42

Motion of the thumb joint Extension at CMC MCP IP

Answer 42

CMC-none MCP-extensor pollicis brevis IP-extensor pollicis longus

Question 43

Motion of the thumb joint Adduction at CMC MCP IP

Answer 43

CMC-none MCP-Adductor pollicis IP-none

Question 44

Motion of the thumb joint Abduction at CMC MCP IP

Answer 44

CMC-abductor pollicis longus MCP-abductor pollicis brevis IP-none

Question 45

Motion of the thumb joint Opposition at CMC MCP IP

Answer 45

CMC-Opponens pollicis MCP-none IP-none

Question 46

What are the cutaneous innervation of hte hand by Median Ulnar Radial

Answer 46

Question 47

Outline the path of the ulnar nerve

Answer 47

C8-T1, goes through the axilla, down the media side of arm, into cubital fossa, run down through Guyon canal-separate from Carpal tunnel. Innervates all of the intrinsic muscles of the hand except the thenar muscles and first two lumbricals (which are innervated by the median nerve)

Question 48

What muscles elevate the scapula

Answer 48

Levator scapule Upper trapezius

Question 49

What muscles depress scapula

Answer 49

Lower trapezius Serratus anterior (lower fibers) Pect minor (indirectly-pec major and latissimus dorsi)

Question 50

What muscles protract scapula

Answer 50

Pect minor (and major) Serratus anterior

Question 51

What muscles retract scapula

Answer 51

Middle trapezius Rhomboids

Question 52

What muscles rotate scapula upward

Answer 52

Upper and lower trapezius serratus anterior

Question 53

What muscles flex arm

Answer 53

Biceps Anterior deltoid Coracobrachialis Pect major-clavicular head

Question 54

What muscles extend arm (and their origin/insertion)

Answer 54

Triceps (3 heads: long-medial humerus to infraglenoid tubercle, medial-