Anatomy 1 - Back/Chest muscles

Question 1

Origin of sternocleidomastoid?

Answer 1

• Superior anterior surface of manubrium
• Superior surface of medial third of clavicle

Question 2

Insertion of sternocleidomastoid?

Answer 2

• Mastoid process of temporal bone (lateral)
• Nuchal line of occipital bone

Question 3

Function of sternocleidomastoid?

Answer 3

• Elevation of clavicle and manubirum of sternum (at sternoclavicular joint)
• F, lateral F, E of neck
• contralateral rotation of the head

Question 4

Origin of subclavius?

Answer 4

Junction of first rib and its cartilage (costal cartilage)

Question 5

Insertion of subclavius?

Answer 5

Posterior inferior surface of middle third of clavicle

Question 6

Function of subclavius?

Answer 6

Depresses clavicle down and forward at the sternoclavicular joint

Question 7

Origin of teres major?

Answer 7

Inferior angle of scapula

Question 8

Insertion of teres major?

Answer 8

Intertubercular groove of the humerus

Question 9

Function of teres major?

Answer 9

• E, ADD, IR, horizontal ABd of the arm (humerus) at the shoulder joint
• Stabilises shoulder/glenohumeral joint

Question 10

Origin of teres minor?

Answer 10

Lateral border of scapula

Question 11

Insertion of teres minor?

Answer 11

Greater tubercle of humerus

Question 12

Function of teres minor?

Answer 12

• ER, ADD, horizontal ABd of arm at shoulder joint
• stabilises shoulder/glenohumeral joint

Question 13

Origin of infraspinatus?

Answer 13

Infraspinous fossa of posterior surface of scapula

Question 14

Insertion of infraspinatus?

Answer 14

Greater tubercle of humerus

Question 15

Function of infraspinatus?

Answer 15

• ER, horizontal ABd of arm at shoulder joint
• Stabilises shoulder/glenohumeral joint

Question 16

Origin of supraspinatus?

Answer 16

Supraspinatous fossa of scapula

Question 17

Insertion of supraspinatus?

Answer 17

Greater tubercle of humerus

Question 18

Function of supraspinatus?

Answer 18

• ABd of arm at shoulder joint
• Stabilises shoulder/glenohumeral joint

Question 19

Origin of serratus anterior?

Answer 19

Ribs 1-9

Question 20

Insertion of serratus anterior?

Answer 20

Medial border of scapula

Question 21

Function of serratus anterior?

Answer 21

• Depression, abduction, upward rotation of the scapula at the scapulothoracic joint
• Elevation of ribs when scapula fixed

Question 22

Origin of subscapularis?

Answer 22

Subscapular fossa of scapula

Question 23

Insertion of subscapularis?

Answer 23

Lesser tubercle of humerus

Question 24

Function of subscapularis?

Answer 24

• IR of arm at shoulder/glenohumeral joint
• Prevents anterior displacement of humerus (stabilises shoulder joint)

Question 25

Origin of levator scapulae?

Answer 25

Transverse processes of vertebrae C1-C4

Question 26

Insertion of levator scapulae?

Answer 26

Superior part of medial border of scapula

Question 27

Function of levator scapulae?

Answer 27

Elevation and downward rotation of scapula at scapulothoracic joint

Question 28

Origin of rhomboid major?

Answer 28

- Spinous processes of vertebrae T2-T5 - Ligamentum nuchae

Question 29

Insertion of rhomboid major?

Answer 29

Medial border of scapula inferior to scapular spine

Question 30

Function of rhomboid major?

Answer 30

- ADD (retraction), downward rotation, elevation of scapula at scapulothoracic joint - Stabilises scapula (like rhomboid minor)

Question 31

Origin of rhomboid minor?

Answer 31

Spinous processes of vertebrae C7-T1

Question 32

Insertion of rhomboid minor?

Answer 32

Medial border of scapula superior to scapular spine (above rhomboid major)

Question 33

Function of rhomboid minor?

Answer 33

- ADD (retraction), downward rotation, elevation of scapula at scapulothoracic joint - Stabilises scapula (like rhomboid major)

Question 34

Origin of trapezius?

Answer 34

- Occipital bone - Ligamentum nuchae - Spinous processes of vertebrae C7-T12

Question 35

Insertion of trapezius?

Answer 35

- Posterior lateral third of clavicle - Acromion - Spine of scapula

Question 36

Function of trapezius?

Answer 36

- Superior fibers: elevation, upward rotation of scapula : E, lateral flexion of neck - Middle fibers: ADD of scapula - Lower fibers: depression and upward rotation of scapula

Question 37

Origin of pectoralis major (clavicular, sternocostal, abdominal part)?

Answer 37

- Anterior surface of medial half of clavicle - Anterior surface of sternum - Anterior layer of rectus sheath

Question 38

Insertion of pectoralis major (clavicular, sternocostal, abdominal part)?

Answer 38

Lateral lip of the intertubercular groove of the humerus

Question 39

Function of pectoralis major (clavicular, sternocostal, abdominal part)?

Answer 39

- Clavicular head (upper part): ADD, IR, F of arm at shoulder joint - Sternocostal head (lower part): E of arm at shoulder joint Depression, downward rotation, ABD of scapula

Question 40

Origin of pectoralis minor?

Answer 40

Ribs 3-5 (costal cartilages)

Question 41

Insertion of pectoralis minor?

Answer 41

Coracoid process of scapula

Question 42

Function of pectoralis minor?

Answer 42

- Depression, downward rotation, ABd of scapula - Elevation of ribs - Stabilises scapula on thoracic wall

Question 43

Origin latissimus dorsi?

Answer 43

- Spinous processes of vertebrae T7-T12 and L1-L5 and sacrum - Thoracolumbar fascia - Ribs 9-12 - Inferior portion of scapula - Posterior third of iliac crest

Question 44

Insertion latissimus dorsi?

Answer 44

Intertubercular groove of humerus (btw pectoralis and teres major)

Question 45

Function latissimus dorsi?

Answer 45

- IR, ADD, E of arm at shoulder joint - Lateral flexion of spine