OINA 1-10

Question 1

What is the proximal and distal attachments of pectoralis major?

Answer 1

Proximal: Clavicular head- anterior surface of medial half of clavicle; Sternocostal head- anterior surface of sternum, superior six costal cartilages, aponeurosis of external oblique muscle

Distal: Lateral lip of intertuberous sulcus of humerus

Question 2

What supplies blood to the pectoralis major?

Answer 2

Pectoral and Clavicular branches of thoracoacromial trunk perforating branches of internal thoracic artery; superior and lateral thoracic arteries

Question 3

What nerve innervates pectoralis major?

Answer 3

Lateral pectoral nerve and medial pectoral nerve

Question 4

What is the action of pectoralis major?

Answer 4

Adducts and medially rotates humerus; acting alone Clavicular head flexes humerus and Sternocostal head extends it from the flexed position

Question 5

What is the proximal and distal attachments of pectoralis minor?

Answer 5

Proximal: 3rd-5th ribs near their costal cartilage

Distal: Medial border and superior surface of coracoid process of scapula

Question 6

What is the blood supply to the pectoralis minor?

Answer 6

Pectoral branch of thoracoacromial trunk; superior and lateral thoracic arteries

Question 7

What nerve innervates pectoralis minor?

Answer 7

Medial pectoral nerve

Question 8

What are the proximal and distal attachments of subclavius?

Answer 8

Proximal: Junction of 1st rib and its costal cartilage

Distal: Inferior surface of middle third of clavicle

Question 9

What is the blood supply to subclavius?

Answer 9

Clavicular branch of thoracoacromial trunk

Question 10

What nerve innervates subclavius?

Answer 10

Nerve to subclavius

Question 11

What is the action of pectoralis minor?

Answer 11

Stabilizes scapula by drawing it inferiorly and anteriorly against the thoracic wall

Question 12

What is the action of subclavius?

Answer 12

Anchors and depresses clavicle

Question 13

What are the proximal and distal attachments of serratus anterior?

Answer 13

Proximal: External surfaces of lateral parts of 1st-8th ribs

Distal: Anterior surface of the medial border of the scapula

Question 14

What is the blood supply to serratus anterior?

Answer 14

Thoracodorsal artery; superior and lateral thoracic arteries

Question 15

What are the proximal and distal attachments of the deltoid?

Answer 15

Proximal: Lateral third of clavicle; acromion and spine of scapula

Distal: Deltoid tuberosity of the humerus

Question 16

What is the blood supply to the deltoid?

Answer 16

Acromial and deltoid branches of the thoracoacromial trunk; anterior and posterior circumflex humeral arteries

Question 17

What nerve innervates the deltoid?

Answer 17

Axillary nerve

Question 18

What is the action of the deltoid?

Answer 18

Clavicular (anterior) part: flexes and medially rotates arm
Acromial (middle) part: abducts arm
Spinal (posterior) part: extends and laterally rotates arm

Question 19

What are the proximal and distal attachments of supraspinatus?

Answer 19

Proximal: Supraspinous fossa of the scapula

Distal: Superior facet of greater tubercle of humerus

Question 20

What is the blood supply to supraspinatus?

Answer 20

Dorsal scapular artery and suprascapular artery

Question 21

What nerve innervates supraspinatus?

Answer 21

Suprascapular nerve

Question 22

What is the action of supraspinatus?

Answer 22

Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles

Question 23

What are the proximal and distal attachments of infraspinatus?

Answer 23

Proximal: Infraspinous fossa of scapula

Distal: Middle facet on greater tubercle of humerus

Question 24

What is the blood supply to infraspinatus?

Answer 24

Suprascapular artery and circumflex scapular artery

Question 25

What nerve innervates infraspinatus?

Answer 25

Suprascapular nerve

Question 26

What is the action of infraspinatus?

Answer 26

Laterally rotates arm and acts with rotator cuff muscles

Question 27

What are the proximal and distal attachments of subscapularis?

Answer 27

Proximal: Subscapular fossa Distal: Lesser tubercle of humerus

Question 28

What is the blood supply to subscapularis?

Answer 28

Subscapular artery

Question 29

What nerve innervates subscapularis?

Answer 29

Upper and lower subscapular nerve

Question 30

What is the action of subscapularis?

Answer 30

Medially rotates arm; as part of the rotator cuff, helps hold head of humerus in glenoid cavity

Question 31

What are the proximal and distal attachments of teres major?

Answer 31

Proximal: Posterior surface of inferior angle of scapula Distal: Medial lip of intertuberous sulcus

Question 32

What is the blood supply to teres major?

Answer 32

Posterior circumflex humeral artery; thoracodorsal artery

Question 33

What nerve innervates teres major?

Answer 33

Lower subscapular nerve

Question 34

What is the action of teres major?

Answer 34

Adducts, extend and medially rotates arm

Question 35

What are the proximal and distal attachments of teres minor?

Answer 35

Proximal: Middle part of lateral border of scapula Distal: Inferior facet on greater tubercle of humerus

Question 36

What is the blood supply to teres minor?

Answer 36

Circumflex scapular artery; posterior circumflex humeral artery

Question 37

What nerve innervates teres minor?

Answer 37

Axillary nerve

Question 38

What is the action of teres minor?

Answer 38

Laterally rotates arm; and acts with rotator cuff muscles

Question 39

What is the action of serratus anterior?

Answer 39

Protracts scapula and holds it against thoracic wall; rotates scapula

Question 40

What nerve innervates serratus anterior?

Answer 40

Long thoracic nerve