Arm

Question 1

ABDUCTOR DIGITI MINIMI (hand)

Answer 1

ORIGIN
Pisiform bone, pisohamate ligament and flexor retinaculum
INSERTION
Ulnar side of base of proximal phalanx of little finger and extensor expansion
ACTION
Abducts little finger at metacarpophalangeal joint
NERVE
Deep branch of ulnar nerve (C8, T1)

Question 2

ABDUCTOR POLLICIS BREVIS

Answer 2

ORIGIN
Tubercle of scaphoid & flexor retinaculum
INSERTION
Radial sesamoid of proximal phalanx of thumb & tendon of extensor pollicis longus
ACTION
Abducts thumb at metacarpophalangeal & carpometacarpal joints
NERVE
Recurrent (muscular) branch of median nerve(C8, T1) occasionally by ulnar nerve

Question 3

ABDUCTOR POLLICIS LONGUS

Answer 3

ORIGIN
Upper posterior surface of ulna and middle third of posterior surface of radius and interosseous membrane between
INSERTION
Over tendons of radial extensors and brachioradialis to base of 1st metacarpal and trapezium
ACTION
Abducts and extends thumb at carpometacarpal joint
NERVE
Posterior interosseous nerve (C6, 7)

Question 4

ADDUCTOR POLLICIS

Answer 4

ORIGIN
Oblique head: base of 2nd and 3rd metacarpals, trapezoid and capitate. Transverse head: palmar border and shaft of 3rd metacarpal
INSERTION
Ulnar sesamoid then ulnar side of base of proximal phalanx and tendon of extensor pollicis longus
ACTION
Adducts carpometacarpal joint of thumb
NERVE
Deep branch of ulnar nerve (T1)

Question 5

ANCONEUS

Answer 5

ORIGIN
Smooth surface at lower extremity of posterior aspect of lateral epicondyle of humerus
INSERTION
Lateral side of olecranon
ACTION
Weak extensor of elbow. Moves (abducts) ulna in pronation
NERVE
Radial nerve (C7, 8)

Question 6

ARTICULARIS CUBITI

Answer 6

ORIGIN
Deep distal surface of medial head of triceps
INSERTION
Posterior capsule of elbow joint
ACTION
Lifts capsule away from joint
NERVE
Radial (C6, 7 , 8)

Question 6

BICEPS BRACHII

Answer 6

ORIGIN
Long head:supraglenoid tubercle of scapula. Short head: coracoid process of scapula with coracobrachialis
INSERTION
posterior border of bicipital tuberosity of radius (over bursa) and bicipital aponeurosis to deep fascia and subcutaneous ulna
ACTION
Supinates forearm, flexes elbow, weakly flexes shoulder
NERVE
Musculocutaneous nerve (C5, 6) (from lateral cord)

Question 7

BRACHIALIS

Answer 7

ORIGIN
Anterior lower half of humerus and medial and lateral intermuscular septa
INSERTION
Coronoid process and tuberosity of ulna
ACTION
Flexes elbow
NERVE
Musculocutaneous nerve (C5, 6) ( from lateral cord). Also small supply from radial nerve (C7)

Question 8

BRACHIORADIALIS

Answer 8

ORIGIN
Upper two thirds of lateral supracondylar ridge of humerus and lateral intermuscular septum
INSERTION
Base of styloid process of radius
ACTION
Flexes arm at elbow and brings forearm into midprone position
NERVE
Radial nerve (C5, 6)

Question 9

CORACOBRACHIALIS

Answer 9

ORIGIN
Coracoid process of scapula with biceps brachii
INSERTION
Upper half medial border of humerus
ACTION
Flexes and weakly adducts arm
NERVE
Musculocutaneous nerve (C5, 6, 7) (from lateral cord)

Question 10

DELTOID

Answer 10

ORIGIN
Lateral third of clavicle, acromion, spine of scapula to deltoid tubercle
INSERTION
Middle of lateral surface of humerus (deltoid tuberosity)
ACTION
Abducts arm, anterior fibers flex and medial rotate, posterior fibers extend and lateral rotate
NERVE
Axillary nerve (C5, 6) (from posterior cord)

Question 11

EXTENSOR CARPI RADIALIS BREVIS

Answer 11

ORIGIN
Common extensor origin on anterior aspect of lateral epicondyle of humerus
INSERTION
Posterior base of 3rd metacarpal
ACTION
Extends and abducts hand at wrist
NERVE
Posterior interosseous nerve (C7, 8)

Question 12

EXTENSOR CARPI RADIALIS LONGUS

Answer 12

ORIGIN
Lower third of lateral supracondylar ridge of humerus and lateral intermuscular septum
INSERTION
Posterior base of 2nd metacarpal
ACTION
Extends and abducts hand at wrist
NERVE
Radial nerve (C6, 7)

Question 13

EXTENSOR CARPI ULNARIS

Answer 13

ORIGIN
Common extensor origin on anterior aspect of lateral epicondyle of humerus
INSERTION
Base of 5th metacarpal via groove by ulnar styloid
ACTION
Extends and adducts hand at wrist
NERVE
Posterior interosseous

Question 14

EXTENSOR DIGITI MINIMI

Answer 14

ORIGIN
Common extensor origin on anterior aspect of lateral epicondyle of humerus
INSERTION
Extensor expansion of little finger-usually two tendons which are joined by a slip from extensor digitorum at metacarpophalangeal joint
ACTION
Extends all joints of little finger
NERVE
Posterior interosseous nerve (C7, 8)

Question 15

EXTENSOR DIGITORUM

Answer 15

ORIGIN
Common extensor origin on anterior aspect of lateral epicondyle of humerus
INSERTION
External expansion to middle and distal phalanges by four tendons. Tendons 3 and 4 usually fuse and little finger just receives a slip
ACTION
Extends all joints of fingers
NERVE
Posterior interosseous nerve (C7, 8)

Question 16

EXTENSOR INDICIS

Answer 16

ORIGIN
Lower posterior shaft of ulna (below extensor pollicis longus) and adjacent interosseous membrane
INSERTION
Extensor expansion of index finger (tendon lies on ulnar side of extensor digitorum tendon)
ACTION
Extends all joints of index finger
NERVE
Posterior interosseous nerve (C7, 8)

Question 17

EXTENSOR POLLICIS BREVIS

Answer 17

ORIGIN
Lower third of posterior shaft of radius and adjacent interosseous membrane
INSERTION
Over tendons of radial extensors and brachioradialis to base of proximal phalanx of thumb
ACTION
Extends metacarpophalangeal joint of thumb
NERVE
Posterior interosseous nerve (C7, 8)

Question 18

EXTENSOR POLLICIS LONGUS

Answer 18

ORIGIN
Middle third of posterior ulna (below abductor pollicis longus) and adjacent interosseous membrane
INSERTION
Base of distal phalanx of thumb via Lister’s tubercle (dorsal tubercle of radius).
ACTION
Extends interphalangeal and metacarpophalangeal joints of thumb
NERVE
Posterior interosseous nerve (C7 , 8 )

Question 19

FLEXOR CARPI RADIALIS

Answer 19

ORIGIN
Common flexor origin of medial epicondyle of humerus
INSERTION
Bases of 2nd and 3rd metacarpals via groove in trapezium and slip to scaphoid
ACTION
Flexes and abducts wrist
NERVE
Median nerve (from medial and lateral cords)

Question 20

FLEXOR CARPI ULNARIS

Answer 20

ORIGIN
Humeral head: common flexor origin of medial epicondyle. Ulnar head: aponeurosis from medial olecranon and upper three quarters subcutaneous border of ulna
INSERTION
Pisiform, hook of hamate, base of 5th metacarpal via pisohamate and pisometacarpal ligaments
ACTION
Flexes and adducts wrist. Fixes pisiform during action of hypothenar muscles
NERVE
Ulnar nerve (C8, T1) (with some C7 by communication from lateral cord)

Question 21

FLEXOR DIGITI MINIMI BREVIS

Answer 21

ORIGIN
Flexor retinaculum and hook of hamate
INSERTION
Ulnar side of base of proximal phalanx of little finger
ACTION
Flexes metacarpophalangeal joint of little finger
NERVE
Deep branch of ulnar nerve (C8, T1)

Question 22

FLEXOR DIGITORUM PROFUNDUS

Answer 22

ORIGIN
Medial olecranon, upper three quarters of anterior and medial surface of ulna as far round as subcutaneous border and narrow strip of interosseous membrane
INSERTION
Distal phalanges of medial four fingers. Tendon to index finger separates early
ACTION
Flexes distal interphalangeal joints, then secondarily flexes proximal interphalangeal and metacarpophalangeal joints and wrist
NERVE
Median nerve (anterior interosseous) and ulnar nerve

Question 23

FLEXOR DIGITORUM SUPERFICIALIS

Answer 23

ORIGIN
Humeral head: common flexor origin of medial epicondyle humerus, medial ligament of elbow. Ulnar head: medial border of coronoid process and fibrous arch. Radial head: whole length of anterior oblique line
INSERTION
Tendons split to insert onto sides of middle phalanges of medial four fingers
ACTION
Flexes proximal interphalangeal joints and secondarily metacarpophalangeal joints and wrist
NERVE
Median nerve (C7, 8) (from medial and lateral cords)

Question 24

FLEXOR POLLICIS BREVIS

Answer 24

ORIGIN Flexor retinaculum and tubercle of trapezium INSERTION Base of proximal phalanx of thumb (via radial sesamoid) ACTION Flexes metacarpophalangeal joint of thumb NERVE Recurrent (muscular) branch of median nerve (C8, T1) (may also be from deep branch of ulnar nerve (T1))

Question 25

FLEXOR POLLICIS LONGUS

Answer 25

ORIGIN Anterior surface of radius below anterior oblique line and adjacent interosseous membrane INSERTION Base of distal phalanx of thumb ACTION Flexes distal phalanx of thumb NERVE Anterior interosseous nerve (C7, 8)

Question 26

INFRASPINATUS

Answer 26

ORIGIN Medial three quarters of infraspinous fossa of scapula and fibrous intermuscular septa INSERTION Middle facet of greater tuberosity of humerus and capsule of shoulder joint ACTION Laterally rotates arm and stabilizes shoulder joint NERVE Suprascapular nerve (C5, 6 ) (from upper trunk)

Question 27

DORSAL INTEROSSEI

Answer 27

ORIGIN Bipennate from inner aspects of shafts of all metacarpals INSERTION Proximal phalanges and dorsal extensor expansion on radial side of index and middle fingers and ulnar side of middle and ring fingers ACTION Abduct from axis of middle finger. Flex metacarpophalangeal joint while extending interphalangeal joints NERVE Deep branch of ulnar nerve (T1)

Question 28

PALMAR INTEROSSEI

Answer 28

ORIGIN Anteriorshafts of 2, 4, 5 metacarpals (unipennate) INSERTION Proximal phalanges and dorsal extensor expansion on ulnar side of index and radial side of ring and little fingers and to ulnar sesamoid of thumb ACTION Adduct to axis of middle finger. Flex metacarpophalangeal joint while extending interphalangeal joints NERVE Deep branch of ulnar nerve (T1)

Question 29

LATISSIMUS DORSI

Answer 29

ORIGIN Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac crest, last four ribs (interdigitating with external oblique abdominis) and inferior angle of scapula INSERTION Floor of bicipital groove of humerus after spiraling around teres major ACTION Extends, adducts and medially rotates arm. Costal attachment helps with deep inspiration and forced expiration NERVE Thoracodorsal nerve (C6, 7, 8) (from posterior cord)

Question 30

LUMBRICALS

Answer 30

ORIGIN Four tendons of flexor digitorum profundus. Radial 2: radial side only (unipennate). Ulnar 2: cleft between tendons ( bipennate) INSERTION Extensor expansion (dorsum of proximal phalanx ) of fingers 2-5 radial side ACTION Flex metacarpophalangeal joints and extend interphalangeal joints of fingers NERVE Lateral 2: median nerve (C8, T1). medial 2: deep branch of ulnar nerve (C8, T1)

Question 31

OPPONEN DIGITI MINIMI HAND

Answer 31

ORIGIN Flexor retinaculum and hook of hamate INSERTION Ulnar border of shaft of 5th metacarpal ACTION Opposes (flexes and laterally rotates) carpometacarpal and metacarpophalangeal joints of little finger NERVE Deep branch of ulnar nerve (C8, T1)

Question 32

OPPONEN POLLICIS

Answer 32

ORIGIN Flexor retinaculum and tubercle of trapezium INSERTION Whole of radial border of 1st metacarpal ACTION Opposes (medially rotates and flexes ) carpometacarpal and metacarpophalangeal joints of thumb NERVE Recurrent (muscular) branch of median nerve (C8,T1) (may also be from deep branch of ulnar nerve (T1))

Question 33

PALMARIS BREVIS

Answer 33

ORIGIN Flexor retinaculum and palmar aponeurosis INSERTION Skin of palm into dermis ACTION Steadies and corrugates skin of palm to help with grip NERVE Superficial branch of ulnar nerve (C8, T1)

Question 34

PALMARIS LONGUS

Answer 34

ORIGIN Common flexor origin of medial epicondyle of humerus INSERTION Flexor retinaculum and palmar aponeurosis ACTION Flexes wrist and tenses palmar aponeurosis NERVE Median nerve (C7, 8) (from medial and lateral cords)

Question 35

PECTORALIS MAJOR

Answer 35

ORIGIN Clavicular head-medial half clavicle. Sternocostal head-lateral manubrium and sternum, six upper costal cartilages and external oblique aponeurosis INSERTION Lateral lip of bicipital groove of humerus and anterior lip of deltoid tuberosity ACTION Clavicular head:flexes and adducts arm. Sternal head: adducts and medially rotates arm . Accessory for inspiration NERVE Medial pectoral nerve (from medial cord) and lateral pectoral nerve (from lateral cord) (C6, 7, 8)