Muscles Of Thorax And Back

Question 1

List 4 superficial muscles

Answer 1

Pectoralis Major, Subclavius, Pectoralis minor, Serratus anterior

Question 2

Which superficial muscle originates at the medial half of clavicle and anterior surface of sternum

Answer 2

Pectoralis Major

Question 3

Where does the Pectoralis major muscle originate?

Answer 3

Medial half of clavicle, anterior surface of sternum, first seven costal cartilages, aponeurosis of external oblique

Question 4

Where does the Pectoralis major insert?

Answer 4

Lateral lip of Inter tubercular sulcus of humerus

Question 5

Action of Pectoralis major muscle

Answer 5

Adduction, Medial rotation, flexión of the humerus at the shoulder joint

Question 6

Innervation of the Pectoralis major muscle

Answer 6

Medial and lateral pectoral nerve

Question 7

Origin of subclavius

Answer 7

Rib I junction between rib and costal cartilage

Question 8

Insertion of subclavius muscle

Answer 8

Groove on inferior surface of middle third of clavicle

Question 9

Action of subclavius muscle

Answer 9

Pulls clavicle medially to stabilise sternoclavicular joint, depresses tip of shoulder joint

Question 10

Innervation of subclavius muscle

Answer 10

Nerve to subclavius

Question 11

Origin of Pectoralis minor muscle

Answer 11

Anterior surface of third, fourth and fifth ribs, and deep fascia overlying the related intercostal spaces

Question 12

Insertion of Pectoralis minor muscle

Answer 12

Coracoid process of scapula

Question 13

Action of Pectoralis minor

Answer 13

Depresses tip of shoulder , protracts scapula

Question 14

Innervation of Pectoralis minor muscle

Answer 14

Medial pectoral nerves

Question 15

Origin of serratus anterior

Answer 15

Anterior portions of first 8 ribs

Question 16

Insertion of serratus anterior

Answer 16

Internal surface of medial border of scapula

Question 17

Action of serratus anterior muscle

Answer 17

Holds scapula against rib cage to prevent winging of inferior angle of scapula

Question 18

Innervation of serratus anterior

Answer 18

Long thoracic nerve

Question 19

List the superficial back muscles

Answer 19

Trapezius, Latissimus Dorsi, Levator scapulae, Rhomboid major, Rhomboid mimor

Question 20

Origin of Trapezius muscle

Answer 20

Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of CVII to TXII

Question 21

Insertion of trapezius muscle

Answer 21

Lateral one third of clavicle , acromion, spine of scapula

Question 22

Innervation of trapezius muscle

Answer 22

Motor accessory nerve (XI) proprioception C3 and C4

Question 23

Function of trapezius muscle

Answer 23

Assists in rotating the scapula during abduction of humerus above horizontal , upper fibres elevates, middle fibres adduction, lower fibres depress scapula

Question 24

Origin of Latissimus dorsi

Answer 24

Spinous process of TVII to LV and sacrum, iliac crest, ribs X to XII

Question 25

Insertion of Latissimus dorsi

Answer 25

Floor of Inter tubercular sulcus of humerus

Question 26

Innervation of Latissimus dorsi

Answer 26

Thoracodorsal nerve (C6- C8)

Question 27

Action of Latissimus Dorsi

Answer 27

Extends, Adducts, Medially rotates humerus

Question 28

Origin of Levator scapulae

Answer 28

Transverse process of CI to CIV

Question 29

Insertion of Levator scapulae

Answer 29

Upper portion medial border of scapula

Question 30

Innervation of Levator scapulae

Answer 30

C3 to C4 and dorsal scapular nerve (C4 & C5)

Question 31

Function of Levator scapulae

Answer 31

Elevates scapula

Question 32

Origin of rhomboid major

Answer 32

Spinous process of TII to TV

Question 33

Insertion of rhomboid major

Answer 33

Medial border of scapula between spine and inferior angle

Question 34

Innervation of rhomboid major

Answer 34

Dorsal scapular nerve (C4& C5)

Question 35

Function of rhomboid major

Answer 35

Retracts ( adducts) and elevates scapula

Question 36

Origin of rhomboid minor

Answer 36

Lower portion of ligamentum nuchae, spinous processes of CVII and TI

Question 37

Insertion of rhomboid minor

Answer 37

Medial border of scapula between spine and inferior angle

Question 38

Innervation of rhomboid minor

Answer 38

Dorsal scapular nerve (C4 &C5)

Question 39

Function of rhomboid minor

Answer 39

Retracts (adducts) and elevates scapula

Question 40

Name the two intermediate group of back muscles

Answer 40

Serratus posterior superior, serratus posterior inferior,

Question 41

Origin of Serratus posterior superior

Answer 41

Lower portion of ligamentum nuchae, spinous process of C7 to T3 and supraspinous ligaments

Question 42

Insertion of Serratus posterior superior

Answer 42

Upper border of ribs 2 to 5 just lateral to their angles

Question 43

Innervation of serratus posterior superior

Answer 43

Intercostal nerves / Anterior rami of upper thoracic nerve (T2 to T5)

Question 44

Function of serratus posterior superior

Answer 44

Elevates ribs 2 to 5

Question 45

Origin of Serratus posterior inferior

Answer 45

Spinous processes of T11 to L3 and supraspinous ligaments

Question 46

Insertion of serratus posterior inferior

Answer 46

Lower border of ribs 9 to 12 just lateral to their angles

Question 47

Innervation of serratus posterior inferior

Answer 47

Intercostal Nevres / Anterior rami of lower thoracic nerves (T9 to T12)

Question 48

Function of serratus posterior inferior

Answer 48

Depresses ribs 9 to 12 and may prevent ribs from being elevated when the diaphragm contracts

Question 49

List two groups of deep back muscles

Answer 49

Spinotransversales Erector spinae

Question 50

Name the two spinotransversales muscles

Answer 50

Splenius capitis, Splenius cervicis

Question 51

Origin of Splenius capitis

Answer 51

Lower aspect of ligamentum nuchae, and spinous processes of C7 to T3/4 vertebrae

Question 52

Insertion of splenius capitis

Answer 52

Mastoid process and the occipital bone

Question 53

Action of splenius capitis

Answer 53

Rotate head the same side

Question 54

Innervation of splenius capitis

Answer 54

Posterior rami of spinal nerves C3 and C4