Muscles (Thorax & Back)

Question 1

Pectoralis Major origin, insertion, innervation, actions

Answer 1

Question 2

Pectoralis minor

origin, insertion, innervation, actions

Answer 2

Axillary artery branches- superior thoracic, thoracoacromial, lateral thoracic (screw the lawyers)

Question 3

Serratus Anterior origin, insertion, innervation, actions

Answer 3

Question 4

Subclavius

origin, insertion, innervation, actions

Answer 4

Question 5

External, Internal, and innermost intercostals

origin, insertion, innervation, actions

Answer 5

External-forced inspiration,
Internal- forced expiration,
Innermost- deepest, elevates ribs

Ext & Innermost don’t go all the way to sternum, Internal does. None go all the way to vertebrae

Question 6

Transversus thoracis origin, insertion, innervation, actions

Answer 6

Question 7

Rhomboid major & minor origin, insertion, innervation, actions

Answer 7

Question 8

Levator Scapulae origin, insertion, innervation, actions

Answer 8

Question 9

Latissimus Dorsi origin, insertion, innervation, actions

Answer 9

Triangle of auscultation- trapezius, latissimus dorsi, medial border of scapula

Question 10

Serratus posterior (sup & inf) origin, insertion, innervation, actions

Answer 10

Question 11

True/False: Extrinsic back muscles (trap, lat, levator, rhomboids, serratus post) are true back muscles.

Answer 11

False, not innervated by dorsal rami

Question 12

Trapezius origin, insertion, innervation, actions

Answer 12

Ligamentum nuchae/Nuchal ligament extends from external occipital protuberance to spinous process of C7. Trapezius attaches superiorly to ligamentum nuchae.

Question 13

Splenius capitis & cervicis origin, insertion, innervation, actions

Answer 13

Question 14

Erector spinae origin, insertion, innervation, actions

Answer 14

I Love Spaghetti (iliocostalis, longissimus, spinalis). Innervated by dorsal rami.

Question 15

What does transversospinalis consist of?

Answer 15

Multifidus (most developed in lumbar region)
Rotatores (brevis spans 1 vertebra, longus spans 2 vertebrae, most developed in thoracic region)

Question 16

Semispinalis (capitis)

origin, insertion, innervation, actions

Answer 16

Deep to the splenius muscle

Question 17

Levatores costarum origin, insertion, innervation, actions

Answer 17

Question 18

Suboccipital triangle

origin, insertion, innervation, actions

Answer 18

rectus capitis major & minor, obliquus capitis superior & inferior innervated by suboccipital nerve C1 (motor only)

Question 19

Sternocleidomastoid origin, insertion, innervation, actions

Answer 19

Innervated by accessory nerve XI. assists in forced inspiration.

Question 20

Deltoid

origin, insertion, innervation, actions

Answer 20

Innervated by axillary nerve.

Actions: Flexion, Extension at shoulder, abduction