arms

Question 1

flexor muscles of elbow

Answer 1

1. brachialis
2. brachioradialis
3. biceps brachii

Question 2

accessory flexor muscles

Answer 2

1. extensor carpi radialis longus
2. pronator teres

Question 3

brachialis

Answer 3

origin: distal half of the anterior surface of the humerus

insertion: coronoid process and tuberosity of the ulna

function:
primary flexor of the elbow joint
(it flexes the forearm in all positions because it inserts on the ulna, which does not rotate)

innervation: musculocutaneous nerve (C5-C6)

Question 4

brachioradialis

Answer 4

origin: lateral supracondylar ridge of humerus

insertion: lateral surface of the distal radius

function:
1. flexes the forearm at the elbow
(especially when the forearm is in a mid-pronated (neutral) position (like when you’re doing a hammer curl)
2. helps in stabilizing the elbow joint during rapid flexion and extension

innervation: radial nerve (C5–C6)

Question 5

biceps brachii (at shoulder level)

Answer 5

origin:
1. long head –> supraglenoid tubercle of the scapula
2. short head –> coracoid process of the scapula

insertion (same for both heads): radial tuberosity of radius

function:
1. weak shoulder flexion
2. assists in abduction
3. assists in shoulder stabilization
4. helps resist dislocation of the shoulder (especially the long head)

innervation: musculocutaneous nerve (C5-C6)

Question 6

extensor carpi radialis longus

Answer 6

origin: lateral supracondylar ridge of the humerus

insertion: base of the 2nd metacarpal bone (dorsal side)

function:
1. wrist extension
2. wrist abduction
3. assists in stabilizing the wrist during finger flexion

innervation: radial nerve (C6-C7)

Question 7

pronator teres

Answer 7

origin:
1. humeral head: medial epicondyle of the humerus
2. ulnar head: coronoid process of the ulna

insertion: lateral surface of the radius (midshaft)

function:
1. pronation of the forearm (turning the palm down)
2. assists with elbow flexion

innervation: median nerve (C6–C7)

Question 8

triceps brachii

Answer 8

origin:
1. long head: infraglenoid tubercle of the scapula
2. lateral head: posterior surface of the humerus, superior to the radial groove
3. medial head: posterior surface of the humerus, inferior to the radial groove

insertion: olecranon of the ulna

function:
1. extension of the forearm at the elbow
(long head only: assists in extension and adduction of the arm at the shoulder)

innervation: radial nerve (C6–C8)

Question 9

anconeus

Answer 9

origin: lateral epicondyle of the humerus

insertion: lateral surface of the olecranon and proximal part of the posterior ulna

function:
1. assists triceps brachii in extending the forearm at the elbow
2. stabilizes the elbow joint

innervation: radial nerve (C7–T1)

Question 10

joints involved in pronation and supination of forearm

Answer 10

superior radio-ulnar joint
inferior radio-ulnar joint

Question 11

superior radio-ulnar joint

Answer 11

synovial pivot joint

allows for the rotation of the forearm

bones involved:
1. head of the radius
2. radial notch of the ulna

annular ligament:
- forms a ring around the head of the radius
- holds the radial head tightly against the ulna (allowing it to rotate in place during pronation/supination)

joint capsule: continuous with that of the elbow joint

Question 12

supination muscles

Answer 12

supinator muscle
biceps brachii

Question 13

pronator muscles

Answer 13

pronator quadratus
pronator teres

Question 14

supinator muscle

Answer 14

location: posterior compartment of the forearm (deep layer)

origin: lateral epicondyle of the humerus and the supinator crest of the ulna

insertion: lateral surface of the proximal radius

innervation: deep branch of the radial nerve

function: supinates the forearm, especially during slow, unresisted movements

Question 15

pronator teres

Answer 15

location: superficial anterior forearm

origin:
1. humeral head: medial epicondyle of the humerus
2. ulnar head: coronoid process of the ulna

insertion: lateral surface of the radius (mid-shaft)

innervation: median nerve

function: pronates the forearm and assists in elbow flexion

Question 16

pronator quadratus

Answer 16

location: deep layer of the anterior forearm (distal end)

origin: distal anterior surface of the ulna

insertion: distal anterior surface of the radius

innervation: anterior interosseous nerve (branch of the median nerve)

function: primary muscle for pronation, especially during slow, unresisted movements

Question 17

joints in wrist

Answer 17

radio-carpal joint
mid carpal joint

Question 18

radio-carpal joint

Answer 18

joint type: synovial, ellipsoid (condyloid) joint

location: btw distal epiphysis of radius and first row of carpal bones

Question 19

mid carpal joint

Answer 19

joint type: synovial, plane and condyloid types (mixed)

location: btw first row of carpal bones and second row of carpal bones

Question 20

carpal bones

Answer 20

proximal row:
1. scaphoid
2. lunate
3. triquetrum
4. pisiform

distal row:
5. trapezium
6. trapezoid
7. capitate
8. hamate

Question 21

scaphoid

Answer 21

most lateral
articulates with radius

most commonly fractured

Question 22

lunate

Answer 22

articulates with radius

most commonly dislocated

Question 23

triquetrum

Answer 23

medial to lunate

Question 24

pisiform

Answer 24

sits on top of triquetrum (palmar view only)

Question 25

trapezium

Answer 25

articulates with 1st metacarpal (thumb)

Question 26

trapezoid

Answer 26

smallest in distal row articulates with 2nd metacarpal

Question 27

capitate

Answer 27

largest carpal bone articulates with 3rd metacarpal

Question 28

hamate

Answer 28

medial has a hook (hamulus) on palmar side ulnar nerve passes nearby → injury = ulnar nerve compression

Question 29

ligaments of the wrist

Answer 29

collateral ligaments 1. lateral 2. medial anterior ligaments 1. palmar radiocarpal 2. palmar ulnocarpal posterior ligaments 1. dorsal radiocarpal 2. dorsal intercarpal

Question 30

collateral ligaments of wrist

Answer 30

LATERAL (attached to styloid process of radius and scaphoid bone) --> divided into: 1. posterior band (from styloid to below lateral aspect of proximal articular surface of scaphoid) 2. anterior band (from anterior edge of radial styloid to scaphoid tubercle) MEDIAL (attached to styloid process of ulna and pisiform and triquetrum bones --> divided into: 1. posterior band (inserted in triquetrum) 2. anterior band (inserted in pisiform)

Question 31

anterior ligaments of wrist

Answer 31

stretched in extension attached to anterior edge of distal surface of radius/ulna and neck of capitate PALMAR RADIOCARPAL LIGAMENT divided into: 1. radio capitate band (btw radius and capitate bone) 2. radio-triquetral band (btw radius and triquetrum) PALMAR ULNOCARPAL LIGAMENT (connects the distal ulna to carpal bones on the ulnar side) 1. ulno-lunate band 2. ulno-triquetral band

Question 32

posterior ligaments of wrist

Answer 32

stretched in flexion DORSAL RADIOCARPAL LIGAMENT (stabilizes the wrist posteriorly and connects the distal radius to carpal bones) 1. radio-lunate band (from distal radius to dorsal surface of lunate) 2. radio-triquetral band (from distal radius to dorsal surface of the triquetrum) DORSAL INTERCARPAL LIGAMENT (from dorsal side of triquetrum to dorsal surfaces of scaphoid, lunate and radius)

Question 33

what do the muscles of the forearm do and how many are there?

Answer 33

there are 17 anterior = flexors and pronators posterior = extensors and supinators

Question 34

how are the flexor muscles in forearm arranged?

Answer 34

in 3 layers 1. superficial anterior layer (muscles attached proximally by common flexor tendon TO medial epicondyle of humerus; common flexor attachment) 2. intermediate layer 3. deep layer

Question 35

forearm flexor muscles

Answer 35

1. superficial anterior layer - pronator teres - flexor carpi radialis - palmaris longus - flexor carpi ulnaris 2. intermediate layer - flexor digitorum superficialis 3. deep layer - flexor digitorum profundos - flexor pollicis longus - pronator quadratura

Question 36

flexor carpi radialis

Answer 36

origin: medial epicondyle of humerus insertion: base of II MC bone function: flexion and abduction of hand at level of wrist innervation: median nerve

Question 37

palmaris longus

Answer 37

origin: medial epicondyle of the humerus insertion: palmar aponeurosis and flexor retinaculum of the hand function: flexion of wrist (weak) and tenses palmar aponeurosis innervation: median nerve

Question 38

flexor carpi ulnaris

Answer 38

origin: medial epicondyle of humerus, olecranon and ulnar posterior border insertion: pisiform, hamate and base of V MC function: flexes and abducts hand innervation: ulnar nerve

Question 39

flexor digitorum superficialis

Answer 39

origin: medial epicondyle insertion: middle phalanges of medial four digits function: flexes middle phalanges at proximal interphalangeal joints of middle four digits innervation: median nerve

Question 40

flexor digitorum profundus