muscle details of upper body

Question 1

biceps brachii (origin/insertion/innervation/blood supply/function)

Answer 1

• Origin:
  Short head -> Apex of the Coracoid process
  Long head -> Supraglenoid tubercle of the scapula
• Insertion
  Radial tuberosity
  bicipital aponeurosis
• Innervation:
  Musculocutaneous nerve (C5- C6)
• Blood supply:
  Branches of brachial artery
• Function:
  Flexion and supination of the forearm at the elbow joint, weak flexor of the arm at the glenohumeral joint

Question 2

Coracobrachialis muscle
(origin/insertion/innervation/blood supply/function)

Answer 2

• Origin
  Coracoid process of the scapula
• Insertion
  Anteromedial surface of the humeral shaft
• Action
  Adduction and flexion of the arm at the shoulder joint
• innervation
  Musculocutaneous nerve (C5- C7)
• Blood supply
  Muscular branches of brachial artery

Question 3

Brachialis (origin/insertion/innervation/blood supply/function)

Answer 3

• Origin
  Distal half of anterior surface of humerus
• Insertion
  Coronoid process of the ulna
• Innervation
  Musculocutaneous nerve (C5,C6); Radial nerve (C7)
• Blood supply
  Brachial artery, radial recurrent artery
• Functions
  Strong flexion of forearm at the elbow joint

Question 4

Triceps brachii (origin/insertion/innervation/blood supply/function)

Answer 4

• Origins
  Long head - infraglenoid tubercle of the scapula
  Medial head - posterior of the humerus (inf)
  Lateral head - posterior of the humerus (sup)
• Insertion
  Olecranon of ulna and fascia of forearm
• Action
  Elbow joint: extension of the forearm
  Shoulder joint: extension and adduction of the arm
• Innervation
  Radial nerve (C6-C8)
• Blood supply
  Deep brachial artery, superior ulnar collateral artery

Question 5

anconeus muscle (origin/insertion/innervation/blood supply/function)

Answer 5

• Origin
  Lateral epicondyle of humerus
• Insertion
  Lateral surface of olecranon
• Action
  Assists in forearm extension at the elbow
  Stabilization of elbow joint
• Innervation
  Radial nerve (C7-C8)
• Blood supply
  Posterior interosseous recurrent artery

Question 6

deltoid
(origin/insertion/innervation/blood supply/function)

Answer 6

• Origins:
  Lateral 1/3 of Clavicle
  Acromion
  Spine of Scapula
• Insertion
  Deltoid tuberosity of humerus
• Innervation
  Axillary nerve (C5, C6)
• Blood supply
  thoracoacromial artery, subscapular artery, anterior and posterior circumflex humeral arteries, deltoid branch of deep brachial artery
• Function
  Clavicular part: flexion and internal rotation
  Acromial part: abduction of the arm
  Spinal part: extension and external rotation

Question 7

subscapularis
(origin/insertion/innervation/blood supply/function)

Answer 7

• Origin
  Subscapular fossa of scapula
• Insertion
  Lesser tubercle of humerus
• Action
  Arm internal rotation
  Stabilizes humeral head in glenoid cavity
• Innervation
  Upper and lower subscapular nerves
• Blood supply
  Suprascapular artery, axillary artery, subscapular artery

Question 8

infraspinatus
(origin/insertion/innervation/blood supply/function)

Answer 8

• Origin
  Infraspinous fossa of scapula
• Insertion
  Greater tubercle of humerus
• Action
  Arm external rotation;
  Stabilizes humeral head in glenoid cavity
• Innervation
  Suprascapular nerve
• Blood supply
  Suprascapular artery, circumflex scapular arteries

Question 9

supraspinatus
(origin/insertion/innervation/blood supply/function)

Answer 9

• Origin
  Supraspinous fossa of scapula
• Insertion
  Greater tubercle of humerus
• Action
  abduction of arm, stabilization of the humeral head in the glenoid cavity
• Innervation
  Suprascapular nerve (C5, C6)
• Blood supply
  Suprascapular artery

Question 10

teres minor
(origin/insertion/innervation/blood supply/function)

Answer 10

• Origin
  Lateral border of scapula
• Insertion
  Greater tubercle of humerus
• Action
  Arm external rotation, arm adduction;
  Stabilizes humeral head in glenoid cavity
• Innervation
  Axillary nerve (C5, C6)
• Blood supply
  Suprascapular artery, dorsal scapular artery

Question 11

teres major
(origin/insertion/innervation/blood supply/function)

Answer 11

• Origins
  Inferior angle and the lateral border of the scapula
• Insertions
  crest of the lesser tubercle of the humerus
• Innervation
  Lower subscapular nerve (C5-C7)
• Blood supply
  Thoracodorsal branch of subscapular artery and posterior circumflex humeral artery
• Function
  Extension and internal rotation of the arm, adduction

Question 12

pectoralis major
(origin/insertion/innervation/blood supply/function)

Answer 12

• Origin
  Clavicular part: medial half of clavicle
  Sternocostal part: anterior surface of sternum
  Costal cartilages of ribs 1-6
  Abdominal part: Anterior layer of rectus sheath
• Insertion
  crest of greater tubercle of humerus
• Action
  Shoulder joint: Arm adduction, Arm internal rotation
  thorax: helps inspiration(rib cage elevation)
• Innervation
  Lateral and medial pectoral nerves (C5-T1)
• Blood supply
  Pectoral branches of thoracoacromial artery, perforating branches of internal thoracic artery

Question 13

pectoralis minor
(origin/insertion/innervation/blood supply/function)

Answer 13

• Origin
  costal cartilages of ribs 3-5
• Insertion
  coracoid process
• Innervation
  Medial and lateral pectoral nerves (C5-T1)
• Blood supply
  Thoracoacromial a. (pectoral and deltoid branches), superior thoracic a., lateral thoracic a.
• Function
  shoulder joint: protraction scapula
  thorax: help inspiration

Question 14

extensor carpi radialis longus

Answer 14

• Origin
  Lateral supracondylar ridge of humerus, lateral intermuscular septum of arm
• Insertion
  Posterior aspect of base of metacarpal bone 2
• Actions
  Wrist joints: Hand extension, hand abduction
• Innervation
  Radial nerve (C5-C8)
• Blood supply
  Radial recurrent artery, radial collateral artery, radial artery

Question 15

extensor carpi radialis brevi

Answer 15

• Origin
  Lateral epicondyle of humerus (common extensor tendon)
• Insertion
  Posterior aspect of base of metacarpal bone 3
• Action
  Wrist joints: Hand extension, hand abduction
• Innervation
  Radial nerve (C5- C6)
• Blood supply
  Radial recurrent artery, radial artery, deep brachial artery

Question 16

Extensor digitorum muscle

Answer 16

• Origin
  Lateral epicondyle of humerus (common extensor tendon)
• Insertion
  Extensor expansions of digits 2-5
• Action
  Finger extension
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Posterior interosseous artery, radial recurrent artery, anterior interosseous artery

Question 17

extensor digiti minimi
(origin/insertion/innervation/blood supply/action)

Answer 17

• Origin
  Lateral epicondyle of humerus (common extensor tendon)
• Insertion
  Extensor expansion of digit 5
• Action
  Finger extension
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Radial recurrent artery, anterior interosseous artery, posterior interosseous artery

Question 18

extensor carpi ulnaris
(origin/insertion/action/innervation/blood supply)

Answer 18

• Origin
  Lateral epicondyle of humerus, posterior border of ulna
• Insertion
  Base of metacarpal bone 5
• Action
  Hand extension and adduction
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Radial recurrent artery, posterior interosseous artery

Question 19

Abductor pollicis longus muscle
(origin/insertion/innervation/blood supply/action)

Answer 19

• Origin
  Posterior surface of proximal half of radius, ulna and interosseus membrane
• Insertion
  Base of metacarpal bone 1(trapezium)
• Action
  Hand extension;
  Thumb abduction and extension
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Anterior interosseous artery, posterior interosseous artery

Question 20

extensor pollicis brevis

Answer 20

• Origin
  Posterior surface of distal third of radius and interosseus membrane
• Insertion
  Posterior aspect of base of proximal phalanx of thumb
• Action
  Thumb extension
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Posterior interosseous artery, anterior interosseous artery

Question 21

Extensor pollicis longus muscle

Answer 21

• Origin
  Posterior surface of middle third of ulna and interosseus membrane
• Insertion
  Posterior aspect of base of distal phalanx of thumb
• Action
  Weak hand extension
  Thumb extension
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Posterior interosseous artery, anterior interosseous artery

Question 22

extensor indicis
(Origin/inserition/innervation/blood supply/action)

Answer 22

• Origin
  Posterior surface of distal ulna
• Insertion
  extensor cap of index finger
• Action
  Weak hand extension
  Finger extension
• Innervation
  Posterior interosseous nerve (radial)
• Blood supply
  Posterior and anterior interosseous artery

Question 23

supinator

Answer 23

• Origin
  Lateral epicondyle of humerus, radial collateral ligament, annular ligament, supinator crest of ulna
• Insertion
  proximal third of radius
• Action
  Forearm supination
• Innervation
  Posterior interosseous nerve (C7, C8)
• Blood supply
  Radial recurrent artery, posterior interosseous artery, posterior interosseous recurrent artery

Question 24

Flexor carpi ulnaris muscle

Answer 24

• Origin
  Medial epicondyle of humerus, olecranon and posterior border of ulna
• Insertion
  Pisiform bone, hamate bone, base of metacarpal bone 5
• Action
  Wrist flexion, wrist adduction
• Innervation
  Ulnar nerve (C7-T1)
• Blood Supply
  Posterior ulnar recurrent artery, ulnar artery

Question 25

palmaris longus

Answer 25

• Origin
  Medial epicondyle of humerus
• Insertion
  Flexor retinaculum, palmar aponeurosis
• Action
  Wrist flexion;Tenses palmar aponeurosis
• Innervation
  Median nerve (C7, C8)
• Blood supply
  Anterior ulnar recurrent artery, median artery

Question 26

flexor carpi radialis

Answer 26

• Origin
  Medial epicondyle of humerus
• Insertion
  Bases of metacarpal bones 2-3
• Action
  Wrist flexion, wrist abduction
• Innervation
  Median nerve (C6, C7)
• Blood supply
  Anterior/posterior recurrent ulnar artery, radial artery

Question 27

pronator teres
(origin/insertion/innervation/blood supply/action)

Answer 27

• Origin
  Humeral head: medial supracondylar
  Ulnar head: Coronoid process of ulna
• Insertion
  Lateral surface of radius
• Action
  Pronation of forearm at the proximal radioulnar joint, flexion of the forearm at the elbow joint
• Innervation
  Median nerve (C6, C7)
• Blood supply
  Branches of brachial, radial and ulnar arteries

Question 28

Flexor digitorum superficialis muscle

Answer 28

• Origin
  Humeroulnar head: Medial epicondyle of humerus, coronoid process of ulna
  Radial head: Proximal half of anterior border of radius
• Insertion
  Sides of middle phalanges of digits 2-5
• Action
  Finger flexion
• Innervation
  Median nerve (C8, T1)
• Blood supply
  Ulnar artery, radial artery, median artery

Question 29

flexor digitorum profundus

Answer 29

• Origin
  Proximal half of anterior surface of ulna, interosseous membrane
• Insertion
  Palmar surfaces of distal phalanges of digits 2-5
• Action
  Finger flexion
• Innervation
  Digits 2-3: Median nerve
  Digits 4-5: Ulnar nerve
• Blood supply
  Ulnar, common interosseous, ulnar collateral, ulnar recurrent, anterior interosseous, median arteries

Question 30

flexor pollicis longus

Answer 30

• Origin
  Anterior surface of radius and interosseous membrane
• Insertion
  Palmar surface of distal phalanx of thumb
• Action
  Thumb flexion
• Innervation
  Median nerve (anterior interosseous nerve C7, C8)
• Blood supply
  anterior interosseous artery (ulnar artery); radial artery

Question 31

pronator quadratus
(origin/insertion/innervation/blood supply/action)

Answer 31

• Origins
  Distal anterior surface of ulna
• Insertion
  Distal anterior surface of radius
• Actions
  forearm pronation
• Innervation
  Median nerve (anterior interosseous nerve, C7, C8)
• Blood supply
  Anterior interosseous artery