Superficial Back

Question 1

Are the Superficial Muscles of Back Extrinsic or Intrinsic? What are their innervation (posterior or anterior rami)?

Answer 1

• Extrinsic Muscles (move UL)
• Innervation: ANTERIOR rami of cervical spinal nerves

Question 2

Answer 2

-Cutaneous branches of posterior (dorsal) rami

Question 3

Answer 3

Trapezius Muscle

Origin:

• Descending Part: Occipital Bone; C1-C7 Spinous Process
• Transverse Part: T1-T4 Aponeurosis
• Ascending Part: T5-T12 Spinous Process

Insertion (See Image):

• Descending Part: Clavicle
• Transverse Part: Acromion
• Ascending Part: Scapular Spine

Innervation: Accessory CN XI

Action:

• Retracts scapula
• Elevates, retracts and depresses scapula

Blood Supply:

• Transverse Cervical Artery

Question 4

Answer 4

Nuchal Ligament

• Part of the proximal attachment of trapezius

Question 5

Answer 5

Latissimus Dorsi

Origin:

• T7-T12 Spinous Process
• Thoracolumbar Fascia
• (inferior angle of scapular; iliac crest)

Insertion:

• Intertubercular sulcus of humerus

Innervation:

• Thoracodorsal nerve (Middle Subscapular n. C6-C8)

Action:

• Extends, ADducts, Medially Rotates Humerus

Blood Supply:

• Thoracodorsal a.

Question 6

Answer 6

Thoracolumbar Fascia

• Part of the proximal attachment of the latissimus dorsi

Question 7

Answer 7

Lumbar Triangle

• Bound by Latissimus Dorsi, the iliac crest, and posterior border of external oblique
• Location of lumbar hernias (fewer muscle layers)

Question 8

Answer 8

Transverse Cervical Artery

• Deep to Trapezius

Question 9

Answer 9

Levator Scapulae

Origin:

• Transverse Processes of C1-C4

Insertion:

• Superior Angle of Scapula

Innervation:

• Dorsal Scapular Nerve (Brachial Plexus; C5 Root)

Action:

• Elevates Scapula

Blood Supply:

• Dorsal Scapular Artery/Transverse Cervical Artery

Question 10

Answer 10

Rhomboid Minor

Origin:

• Spinous Processes C6 & C7

Insertion:

• Medial border of scapula (at scapular spine)

Innervation:

• Dorsal Scapular Nerve (Brachial Plexus; C5)

Action:

• Elevate, Retract, and Inferiorly Rotate Scapula

Blood Supply:

• Dorsal Scapular a./Transverse cervical a.

Question 11

Answer 11

Rhomboid Major

Origin:

• Spinous process of T1-T4

Insertion:

• Medial border of scapula (below scapular spine)

Innervation:

• Dorsal Scapular Nerve (Brachial Plexus; C5)

Action:

• Elevate, Retract and Inferiorly Rotate Scapula

Bloody Supply:

• Dorsal scapular a./Transverse cervical a.

Question 12

Answer 12

Triangle of Ausculation

Borders:

• Trapezius
• Latissimus Dorsi
• Rhomboid Major

Clinical Relevance:

• Listen to respiratory sounds (fewer mm. covering spot)

Question 13

Dorsal Scapular Nerve

Answer 13

Deep to Rhomboid mm.

Runs with branches of dorsal scapular artery

• Innervates:
  
  • Levator Scapulae
  • Rhomboid Minor
  • Rhomboid Major