Superficial Extrinsic Back Muscles
<answer>
<strong>(1st Layer)</strong>
Trapezius
Latissimus Dorsi

<strong>(2nd Layer)</strong>
Levator Scapulae
Rhomboid Minor
Rhomboid Major
</answer>

Superficial extrinsic back muscles attach to the...
Upper Limb - appendicular skeleton

Intermediate Extrinsic Back Muscles
Serratus Posterior Superior
Serratus Posterior Inferior

Intermediate extrinsic back muscles attach to the...
Ribs

Trapezius: Attachments
<answer>
External Occipital Protuberance 
Medial 1/3 Superior Nuchal Line 
Nuchal Ligament (to C7)
Spinous Processes C7-T12

Spine of the Scapula
Acromion (medial edge)
Lateral 1/3 of clavicle
</answer>

Trapezius: Innervation & Blood Supply
<answer>
Spinal Accessory Nerve (CN XI) for motor. 
C3, C4 spinal nerves for pain (sensory) and procioceptive fibers

Transverse Cervical A. (superficial branch)

(additional contributions from acromial branch of suprascapular a. and dorsal branches of posterior intercostal arteries)
</answer>

Trapezius: Action
<answer>
Descending elevates scapula
Middle retracts scapula
Ascending depresses scapula

Descending and Ascending combined rotates glenoid cavity superiorly
</answer>

Latissimus Dorsi: Attachments
<answer>
T7 - T12 spinous processes 
Thoracolumbar fascia
Iliac crest
Ribs 9 - 12 (inferior 3 or 4 ribs)

Floor of intertubercular sulcus (bicipital groove) of humerus medial to the insertion of pectoralis major
</answer>

Latissimus Dorsi: Innervation & Blood Supply
<answer>
Thoracodorsal N. (<strong>C6, C7</strong>, C8)
(originates from posterior cord of brachial plexus, sometimes called middle scapular nerve)

Thoracodorsal A. 
(branch of subscapular a.)
</answer>

Latissimus Dorsi: Action
<answer>
Extends, adducts, and medially rotates humerus. 

Raises body toward arms during climbing.
</answer>

Rhomboid Minor: Attachments
<answer>
Spinous processes of C7 - T1

Root of scapular spine (medial end)
</answer>

Rhomboid Minor: Innervation and Blood supply
<answer>
Dorsal Scapular nerve (C4, C5)

Transverse Cervical A. (deep branch)

Note: sometimes called dorsal scapular a. but not very accurate
</answer>

Rhomboid Minor: Actions
<answer>
Retracts scapula
Elevates scapula

With other muscles it rotates scapula to depress gleniod cavity.
</answer>

Rhomboid Major: Attachments
<answer>
Spinous processes of T2-T5 vertebrae

Medial border of scapula (inferior to root of scapular spine)
</answer>

Rhomboid Major: Innervation & Blood Supply
<answer>
Dorsal Scapular nerve (C4, C5)

Transverse Cervical A. (deep branch)

Note: sometimes called dorsal scapular a. but not very accurate
</answer>

Rhomboid Major: Actions
<answer>
Retracts scapula
Elevates scapula

With other muscles it rotates scapula to depress gleniod cavity.
</answer>

Levator Scapulae: Attachments
<answer>
C1 - C4 transverse processes (posterior tubercles)

Medial border of scapula (superior to root of scapular spine)
</answer>

Levator Scapulae: Innervation & Blood Supply
<answer>
Anterior Rami (C3, C4) 
Dorsal Scapular N. (C4, <strong>C5</strong>)

Transverse Cervical A. (deep branch)
</answer>

Levator Scapulae: Actions
<answer>
Elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

Extends or laterally flexes neck when scapula are fixed
</answer>

Serratus Posterior Superior: Attachments
<answer>
Lower part of ligamentum nuchae
C7 - T3 spinous processes

Ribs 2 - 4 (superior border)
</answer>

Serratus Posterior Superior: Innervation & Blood Supply
<answer>
Anterior Rami!!! 
(T2 - T5 intercostal nerves)

Intercostal arteries
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Serratus Posterior Superior: Actions
Proprioreception
Elevate upper ribs (forced respiration)

Serratus Posterior Inferior: Attachments
<answer>
T11 - L2 spinous processes

Ribs 8 - 12 (inferior border)
</answer>

Serratus Posterior Inferior: Innervation & Blood Supply
<answer>
Anterior Rami!!! 
(T9 - T11 intercostal nerves; T12 subcostal n.)

Intercostal arteries
</answer>

Serratus Posterior Inferior: Actions
Proprioreception
Stabilize lower ribs against diaphragm contraction