Gross Anatomy 2:Superficial Back

Kulesza

Readings:Snell, Clinical Anatomy by Regions (8th edition)• The Superficial Part of the Back and the Scapular

Region: p. 454 –458; table 9-2• Page 63; table 2-1 [serratus posterior muscles]

Objectives:1. Identify the superficial landmarks associated with the

back.2. Describe the structure, function and support of the

superficial muscles of the back (arterial supply, venous drainage and innervation).

3. Identify the borders and functional significance of the triangle of auscultation and the lumbar triangle.

Superficial Landmarks

• Median Vertebral Furrow• Erector Spinae• External occipital protuberance• Spinous Processes, vertebra

prominens (C7)• Cervical border of trapezius• Acromion• Deltoid• Scapula and its spine• Posterior axillary fold• Iliac crest

Dermatomes

Sternoclavicular and Scapulothoracic

Articulations

An 18-year-old male presents following a mountain biking accident. History reveals he was thrown from the bike and landed on the side of his head (he was wearing a helmet). Physical exam reveals a fracture clavicle.

On a follow-up visit, the fracture has healed but he has weakness in shrugging his shoulder and in retracting the scapula. Physical exam reveals atrophy of the trapezius.

What nerve was most likely damaged in the accident? ---Spinal accessory nerve

Trapezius

Proximal attachment: superior nuccal ligament

Distal attachment:

Action:

Innervation: CN XI (& contributions from CN’s II, III, IV)

Latissimus Dorsi

Proximal attachment:

Distal attachment:

Action:

Innervation:

Trapezius & Latissimus Dorsi

Trapezius & Latissimus Dorsi

Innervation of the Trapezius

Innervation of the Trapezius

2nd Layer of Superficial Back Muscles

Levator Scapulae

Proximal attachment:

Distal attachment:

Action:

Innervation:

Rhomboids

Proximal attachment:

Distal attachment:

Action:

Innervation:

Superficial Back Triangles

Triangle of Auscultation:

Lumbar Triangle:

• Inferior Lumbar Hernia (Petit’s Hernia)

Superior Lumbar Hernia (Grynfeltt’s Hernia)

Intermediate Back Muscles*respiratory muscles*Serratus Posterior Superior:Proximal attachment:

Distal attachment:

Action:

Innervation:

Serratus Posterior Inferior:Proximal attachment:

Distal attachment:

Action:

Innervation:

Common Variations of the Transverse/Superficial Cervical Artery

Common Variations of the Transverse/Superficial Cervical Artery