Anatomy Exam #1 Thorax + Back Muscles

Pectoralis Major Action

adducts, medially rotates humerus

Pectoralis Major Innervation

medial/lateral pectoral nerves

Pectoralis Major Proximal Attatchment (origin)

clavicle, sternum, costal cartilage

Pectoralis Major Distal Attatchment (insertion)

humerus

Pectoralis Minor action

pulls scapula anteriorly

Pectoralis Minor innervation

medial pectoral nerve

Pectoralis Minor Proximal Attatchment (origin)

ribs 3-6

Pectoralis Minor Dorsal Attatchment (insertion)

coracoid process of scapula

Deltoid Action

abducts, flexes, extends humerus

Deltoid innervation

axillary nerve

Deltoid Proximal Attatchment (origin)

claivcle, acromion and spine of scapula

Deltoid Distal Attatchment (insertion)

humerus

Serratus Anterior Action

protracts scapula and holds it against thoracic wall

Serratus Anterior innervation

long thoracic nerve

Serratus Anterior Proximal Attatchment (origin)

Ribs 1-8

Serratus Anterior Distal Attatchment (insertion)

medial border of scapula

Lattisimus Dorsi action

adducts, extends, and internally rotates the humerus at the shoulder

Lattisimus Dorsi Innervation

thoracodorsal nerve

Latissimus Dorsi Proximal Attatchment

thoracolumbar fascia

Latissimus Dorsi Distal Attatchment (insertion)

humerus

Transversus Thoracis action

depresses ribs

Transversus Thoracis innervation

intercostal nerves

Transversus Thoracis Proximal Attatchment (origin)

internal surface of ribs 2-7

Transversus Thoracis distal attatchment (insertion)

Internal surface sternum and costal cartilages

External Intercostal muscles action

Move ribs superiorly 

External intercostals innervation

intercostal nerves

external intercostal proximal attatchment (origin)

inferior border of ribs

external intercostal distal attatchment (insertion)

superior border of ribs

internal intercostal muscles action

move ribs inferiorly

internal intercostals innervation

intercostal nerves

Internal intercostal proximal attatchment (origin)

inferior border of ribs

internal intercostal proximal attatchment

inferior border of ribs

internal intercostal distal attatchment

superior border of ribs

trapezius action

rotation, retraction, elevation, and depression of scapula

trapezius innervation

cranial nerve 11, spinal nerves C3-C4

trapezius proximal attatchment

external occipital protuberance, spinous processes

trapezius distal attatchment

clavicle, acromion process, spine of scapula

rhomboid major action

retracts scapula and rotates it to depress glenoid cavity

rhomboid major innervation

Dorsal Scapular Nerve (C4 and C5)

rhomboid major proximal attatchment

spinous processes T2-T5

rhomboid major distal attatchment

medial border of scapula, inferior to insertion of rhomboid minor

rhomboid minor action

retracts and rotates scapula, fixes scapula to thoracic wall

rhomboid minor innervation

dorsal scapular (C4-C5)

rhomboid minor proximal attatchment

spinous processes of C7-T1

rhomboid minor distal attatchment

medial border of scapula, superior to insertion of rhomboid major

levator scapulae action

elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

levator scapulae innervation

cervical nerves C3-C4, dorsal scapular nerve C5

levator scapulae proximal attatchment

posterior tubercles of transverse processes of C1-C4

levator scapulae distal attatchment

superior part of medial border of scapula

Serratus posterior superior action

elevates ribs which aids in inspiration

serratus posterior superior innervation

intercostal nerves 2-5

serratus posterior superior proximal attatchment

spinous processes of vertebrae C7-T3

serratus posterior superior distal attatchment

upper borders of ribs 2-5

what 3 muscles make up the erector spinae?

iliocostalis, longissimus, and spinalis

action of all three components of erector spinae

unilaterally: flex head and neck to the same side

bilaterally: extend the vertebral column

erector spinae innervation

posterior branch of spinal nerve

iliocostalis proximal attatchment

sacrum, iliac crest, spinous process of lower lumbar and thoracic vertebrae

iliocostalis distal attatchment

ribs

longissimus proximal attatchment

transverse process

longissimus distal attatchment

transverse process

spinalis proximal attatchment

thoracis: spinous process of upper lumbar and lower thoracic vertebrae

cervicis: nuchal ligament and spinous process of C7

spinalis distal attatchment

thoracis: spinous process of upper thoracic vertebrae

cervicis: spinous process of cervical vertebrae except atlas