Upper Extremities: Muscles, Innervations, & Blood Supply

Question 1

Pectoralis Major M.

Answer 1

Innervation: Medial & Lateral Pectoral Nerves

Blood Supply: Pectoral Branch of the Thoracoacromial Trunk

Action:
Medially rotate humeral head
Protract scapula
depress scapula

Question 2

Pectoralis Minor M.

Answer 2

Innervation: Medial Pectoral Nerve

Blood Supply: Pectoral Branch of the Thoracoacromial Trunk

Action:
stabilize the scapula by depression and protraction

Question 3

Serratus Anterior M.

Answer 3

Innervation: Long thoracic Nerve

Blood Supply: Lateral Thoracic Artery

Action:
protract scapula
rotate glenoid cavity superiorly because serratus anterior binds to the medial border of the scapula

Question 4

Subclavius M.

Answer 4

Innervation: Subclavian Nerve

Blood Supply: Acromial Branch of the Thoracoacromial Trunk

Action: Stabilize clavicle and depress clavicle

Question 5

Supraspinatus M.

Answer 5

Innervation: Suprascapular Nerve

Blood Supply: Supracscapular Artery of the Thyrocervical Trunk

Action:
Abduct humerus because it is attached to medial portion of the humerus (greater tubercle)
Hold humeral head in the glenoid fossa of the scapula

Question 6

Infraspinatus M.

Answer 6

Innervation: Suprascapular Nerve

Blood Supply: Suprascapular Artery of Thyrocervical Trunk

Action:
laterally rotate humerus as it is attached to the posterior aspect of humerus
Holds the humeral head in the glenoid cavity

Question 7

Teres Major M.

Answer 7

Innervation: Subscapular Nerve

Blood Supply: Circumflex Scapular Artery

Action: adducts the humerus closer to the body
medially rotates the humerus

Question 8

Teres Minor M. *

Answer 8

Innervation: Axillary Nerve

Blood Supply: Posterior Circumflex Humeral Artery

Action: laterally rotate the humerus
holds humeral head in glenoid cavity

Question 9

Deltoid M. *

Answer 9

Innervation: Axillary Nerve

Blood Supply: Posterior Circumflex Humeral Artery

Action: helps flex the shoulders above the head

Question 10

Coracobrachialis M.

Answer 10

Innervation: Musculocutaneous Nerve

Blood Supply: Brachial Artery

Action: Adducts humerus
Flex humerus

Question 11

Brachialis M.

Answer 11

Innervation: Musculocutaneous Nerve

Blood Supply: Brachial Artery

Action: Flexes the forearm because its insertion is on the ulnar tuberosity

Question 12

Longhead of Biceps Brachii M.

Answer 12

Innervation: Musculocutaneous Nerve

Blood Supply: Brachial Artery

Action: Flex humerus
Flex supine forearm
Supinate forearm

Question 13

Short Head of Biceps Brachii M.

Answer 13

Innervation: Musculocutaneous Nerve

Blood Supply: Brachial Artery

Action: Flex humerus
Flex supine forearm
Supinate forearm

Question 14

Longhead of Triceps Brachii M.

Answer 14

Innervation: Radial Nerve

Blood Supply: Deep Brachial Artery

Action: Resist shoulder dislocation (attached to lateral
border of scapula)
Extend elbow

Question 15

Medial Head fo Triceps Brachii M.

Answer 15

Innervation: Radial nerve

Blood Supply: Deep Brachial Artery

Action: Resist shoulder dislocation
Extend elbow

Question 16

Lateral Head of Triceps Brachii M.

Answer 16

Innervation: Radial nerve

Blood Supply: Deep Brachial Artery

Action: Resist shoulder dislocation
Extend Elbow

Question 17

Aconeus M.

Answer 17

Innervation: Radial Nerve

Blood Supply: Middle Collateral Branch of Deep Brachial Artery

Action: Extend Elbow with Triceps brachii muscle
Stabilizes elbow joint

Question 18

Flexor Carpii Radialis M.

Answer 18

Innervation: Median Nerve

Blood Supply: Ulnar Artery

Action: Abduct hand at wrist

Inserts at medial epicondyle–> base of 2nd metacarpal bone

Question 19

Palmaris Longus M.

Answer 19

Innervation: Median Nerve

Blood Supply: Ulnar Artery

Action: Flex hand at wrist
Inserts at medial epicondyle and attaches to palmar aponeurosis

Question 20

Flexor Carpii Ulnaris M.*

Answer 20

Innervation: Ulnar Nerve

Blood Supply: Ulnar Artery

Action: Adduct hand at wrist

Inserts at medial epicondyle and attaches at the pisiform bone

Question 21

Pronator Teres M.

Answer 21

Innervation: Median Nerve

Blood Supply: Ulnar Artery

Action: Pronates forearm
flexes forearm

Inserts at the medial epicondyle and attaches at the lateral aspect of the radius

Question 22

Flexor Digitorium Superficialis M.*

Answer 22

Innervation: Ulnar Nerve

Blood Supply: Ulnar Artery

Action: Flexes the metacarpophalangeal joints at the wrist
Flexes forearm
Flexes hand at wrist

Inserts at medial epicondyle and attaches at the phalanges 2-5

Question 23

Flexor Digitorum Profundus M.

___

Answer 23

Innervation: Anterior Interosseous Nerve of Median Nerve

Blood Supply: Anterior Interosseous Artery

Action: Flexes the hand at the wrist
Inserts at medial epicondyle and extends all the way to the tips of all the fingers 2-5

Question 24

Flexor Pollicus Longus M. **

Answer 24

Innervation: Anterior Interosseous Nerve of Median Nerve

Blood Supply: Anterior Interosseous Artery

Action: flexes the first carpometacarpal joint
flexes the wrist at the hand
flexes the 1st metacarpophalangeal joint

Inserts in the interosseous membrane and the anterior aspect of radius –> phalanx of the pollex

Question 25

Pronator Quadratus M. **

Answer 25

Innervation: Anterior Interosseous Nerve of Median Nerve Blood Supply: Anterior Interosseous Artery Action: Pronate the forearm Insert at distal ulnar end to the distal radius end

Question 26

Brachioradialis M.

Answer 26

Innervation: Radial Nerve Blood Supply: Radial Recurrent Artery Action: Flex forearm Inserts at supracondylar ridge of the humerus to the lateral distal aspect of the radius

Question 27

Extensor Carpi Radialis Longus M.

Answer 27

Innervation: Radial Nerve Blood Supply: Radial Artery Action: Extend the hand at the wrist Attaches to the 2nd metacarpal from the supracondylar ridge of the humerus

Question 28

Extensor Carpi Radialis Brevis M.

Answer 28

Innervation: Deep Radial Nerve Blood Supply: Radial Artery Action: Extend the hand at the wrist Attaches to the lateral epicondyle of the humerus to the 3rd metacarpal bone

Question 29

Extensor Digitorum M.

Answer 29

Innervation: Posterior Interosseous Nerve Blood Supply : Interosseous Recurrent and Posterior Interosseous artery Action: extend the hand at the wrist Attaches to the lateral epicondyle and extends all the way down to digits 2-5

Question 30

Extensor Digiti Minimi M.

Answer 30

Innervation: Posterior Interosseous Nerve Blood Supply: Interosseous Recurrent Artery Action: extend hand at wrist Attaches to the lateral epicondyle of the humerus and extends all the way to the 5th digit insertion

Question 31

Extensor Carpi Ulnaris Muscle

Answer 31

Innervation: Posterior Interosseous Nerve Blood Supply: Ulnar Artery Action: extends hand at wrist Attaches to the lateral epicondyle to the 5th digit on posterior side

Question 32

Extensor Indicis Muscle

Answer 32

Innervation: Posterior interosseous nerve Blood Supply: Posterior Interosseous Artery Action: extend hand at wrist Attaches to the posterior aspect of the distal ulna and attaches to the 2nd digit via aponeurosis till the tip

Question 33

Abductor Pollicis Longus (Outcropping muscle) M.

Answer 33

Innervation: posterior interosseous nerve Blood Supply: Posterior Interosseous Artery Action: abduct the pollex (thumb) Attaches from the distal end of the radius all the way to the base of the 1st metacarpal of the pollex

Question 34

Extensor Pollicis Brevis M. (Outcropping Muscle)

Answer 34

Innervation: Posterior Interosseous Nerve Blood Supply: Posterior Interosseous Artery Action: Extend the pollex (thumb) Attaches from the posterior end of the radius all the way to the base of the 1st proximal phalanx

Question 35

Extensor Pollicis Longus M. (Outcropping Muscle)

Answer 35

Innervation: posterior interosseous Nerve Blood Supply: Posterior Interosseous Artery Action: Extend the pollex (thumb) Attaches from the posterior end of the radius to the 1st distal phalynx of the pollex (thumb)