cubital fossa/anterior forearm LOs

Question 1

abductor pollicis longus m.

Answer 1

• BL: proximal posterior radius/ulna, interossesous membrane > base of first metacarpal, trapezium
• action: adducts/extends thumb at carpometacarpal joint, abducts hand at wrist (radial deviation)
• innervation: radial nerve
• SC: C6-8

Question 2

brachioradialis m.

Answer 2

• BL: lateral supracondylar ridge of humerus > distal radius lateral to styloid process
• action: flexes elbow
• innervation: radial nerve
• SC: C5-6

Question 3

extensor carpi radialis brevis m.

Answer 3

• BL: lateral epicondyle of humerus > base of 3rd metacarpal
• action: extends and abducts hand at wrist
• innervation: radial nerve
• SC: C6-8

Question 4

extensor carpi radialis longus m.

Answer 4

• BL: lateral supracondylar ridge of humerus > base of 2nd metacarpal
• action: extends and abducts hand at wrist, assists in elbow flexion
• innervation: radial nerve
• SC: C6-8

Question 5

extensor carpi ulnaris m.

Answer 5

• BL: lateral epicondyle of humerus > base of 5th metacarpal
• action: extends and adducts wrist
• innervation: radial nerve
• SC: C6-8

Question 6

extensor digitorum m.

Answer 6

• BL: lateral epicondyle of humerus > extensor expansions of digits 2-5
• action: extends phalanges (at metacarpophalangeal, second at interphalangeal), extends wrist
• innervation: radial nerve
• SC: C6-8

Question 7

extensor digiti minimi m.

Answer 7

• BL: lateral epicondyle of humerus > digitial expansion of 5th digit
• action: extends 5th digit (metacarpophalangeal and interphalangeal)
• innervation: radial nerve
• SC: C7-8

Question 8

extensor indicis m.

Answer 8

• BL: posterior surface of ulna, interosseous membrane > digital expansion of 2nd digit
• action: extends 2nd digit (metacarpophalangeal and interphalangeal)
• innervation: radial nerve
• SC: C7-8

Question 9

extensor pollicis brevis m.

Answer 9

• BL: posterior radial surface, interosseous membrane > base of 1st proximal phalanx
• action: extends thumb (metacarpophalangeal), extends and abducts CMC joint
• innervation: radial nerve
• SC: C6-8

Question 10

extensor pollicis longus m.

Answer 10

• BL: middle 1/3 of posterior ulna, interosseous membrane > base of 1st distal phalanx
• action: extends thumb (CMC, metacarpophalangeal, interphalangeal)
• innervation: radial nerve
• SC: C6-8

Question 11

flexor carpi radialis m.

Answer 11

• BL: medial epicondyle > palmar aspect of base of 2nd metacarpal
• action: flexes and abducts hand at wrist, pronation of forearm, flexion of elbow
• innervation: median nerve
• SC: C6-8

Question 12

flexor carpi ulnaris m.

Answer 12

• BL: medial epicondyle, proximal ulnar shaft > pisiform
• action: flexes and adducts hand at wrist, flexion of elbow
• innervation: ulnar nerve
• SC: C7-T1

Question 13

flexor digitorum profundus m.

Answer 13

• BL: anterior proximal 2/3 of ulna, interosseous membrane > base of distal phalanges of digits 2-5
• action: flexion of digits 2-5 (metacarpophalangeal, distal interphalangeal, proximal interphalangeal), flexion of hand at wrist
• innervation: anterior interosseous of median nerve (digits 2-3), ulnar nerve (digits 4-5)
• SC: C7-T1

Question 14

flexor digitorum superficialis m.

Answer 14

• BL: medial epicondycle > sides of middle phalanges of digits 2-5
• action: flexion of digits (metacarpophalanges, PIP), flexion of hand at wrist
• innervation: median nerve
• SC: C7-T1

Question 15

flexor pollicis longus m.

Answer 15

• BL: anterior surface of radius, interosseous membrane > base of distal phalanx of thumb
• action: flexes thumb (metacarpophalangeal and interphalangeal)
• innervation: anterior interosseous nerve of median n.
• SC: C7-T1

Question 16

palmaris longus m.

Answer 16

• BL: medial epicondyle > palmar aponeurosis
• action: flexes hand at wrist, tenses palmar fascia
• innervation: median nerve
• SC: C7-8

Question 17

pronator quadratus m.

Answer 17

• BL: anterior surface of distal ulna > anterior surface of distal radius
• action: ponates forearm
• innervation: anterior interosseous nerve of median nerve
• SC: C8-T1

Question 18

pronator teres m.

Answer 18

• BL: medial epicondyle, ulnar coronoid process > lateral aspect of radius
• action: pronates and flexes forearm
• innervation: median nerve
• SC: C6-7

Question 19

supinator m.

Answer 19

• BL: lateral epicondyle, radial collateral ligament, supinator crest of ulna > lateral surface of proximal radius
• action: supinates forearm
• innervation: radial nerve
• SC: C5-6

Question 20

humeroulnar joint classification

Answer 20

ginglymus/hinge

Question 21

humeroradial joint classification

Answer 21

radial/gliding

Question 22

proximal radio-ulnar joint classification

Answer 22

pivot/trochoid

Question 23

ulnar collateral ligament

Answer 23

• attachments: medial epicondyle > medial margin of coronoid process, olecranon process
• function: resists excessive cubital valgus

Question 24

radial collateral ligament

Answer 24

• attachments: lateral epicondyle > anular ligament
• function: resists excessive cubital varus

Question 25

annular ligament

Answer 25

• attachments: anterior margin of radial notch > posterior margin of radial notch surrounding head of radius
• function: stabilizes proximal radioulnar joint

Question 26

interosseous membrane

Answer 26

• attachment: interosseous border of radius > interosseous border of ulna

Question 27

collateral circulation around elbow

Answer 27

axillary artery | teres major | brachial artery

• ulnar side:
  
  • superior ulnar collateral <> posterior ulnar recurrent (ulnar a.)
  • inferior ulnar collateral <> anterior ulnar recurrent (ulnar a.)
  • brachial | ulnar | superficial palmar arch
• brachial | common interosseous | anterior interosseous, posterior interosseous (recurrent interosseous)
• radial side:
  
  • profunda brachii | radial collateral, middle collateral
  • radial collateral <> radial recurrent
  • middle collateral <> recurrent interosseous
  • brachial | radial | deep palmar arch

Question 28

location/function of bursae at elbow

Answer 28

• subcutaneous bursa of medial epicondyle
• subcutaneous bursa at leteral epicondyle
• bursa of anconeus
• bursa at origin of extensor carpi radialis brevis
• olecranon bursa (between triceps tendon and olecranon): subtendinous, intratendinous, subcutaneous

Question 29

radial head subluxation

Answer 29

• proximal radial head subluxates from anular ligament on lateral side of elbow due to pulling force
  
  • monkey bars, swinging child by hands
  • radial head not fully ossified in childhood

Question 30

olecranon bursitis

Answer 30

• in posterior elbow joint olecranon bursae
• after repeated, prolonged pressure
• bursae are irritated and compressed, causing fluid buildup

Question 31

fascial compartment of the anterior forearm

Answer 31

• action: flexion and pronation
• contents: superficial, intermediate, deep layers
  
  • superficial layer:
    
    • median nerve: pronator teres, flexor carpi radialis, palmaris longus
    • ulnar nerve: flexor carpi ulnaris
  • intermediate layer:
    
    • median nerve: flexor digitorum superficialis
  • deep layer:
    
    • median and ulnar nerves: flexor digitorum profundus
    • anterior interosseous nerve of median nerve: flexor pollicis longus, pronator quadratus
• innervation: mostly median nerve
• blood supply: ulnar nerve

Question 32

predict nerovascular injuries base on fracture at medial epicondyle of humerus

Answer 32

• brachial artery: inferior/superior ulnar collateral, posterior/anterior ulnar recurrent arteries
• ulnar nerve, median nerve

Question 33

Answer 33

ulna (cross section)

Question 34

Answer 34

radius (cross section)

Question 35

Answer 35

flexor digitorum superficialis (corss section)

Question 36

Answer 36

flexor digitorum profundus (cross section)

Question 37

Answer 37

flexor carpi ulnaris (cross section)

Question 38

Answer 38

extensor indicis (cross section)

Question 39

Answer 39

interosseous membrane (cross section)

Question 40

Answer 40

pronator quadratus (cross section)