2.1 Pectoral Region

Question 1

Identify the Cephalic vein. Into what vein does this drain?

Answer 1

Drains into subclavian vein.

Question 2

Identify the Deltopectoral groove

Answer 2

Between deltoid and pectorals muscles

Question 3

Identify the Deltoid muscle, its attachments and function, and neurovasculature.

Answer 3

• Originates from clavicle, acromion, and scapular spine.
• Inserts into deltoid tuberosity of the humerus.
• Main function is to abduct the arm.
• Blood supply from deltoid branch of thoracoacromial artery as well as posterior humeral circumflex, both of which branch from axillary artery.
• Innervated by axillary nerve (C5-C6).

Question 4

Identify the Pectoralis major, its attachments and function, and neurovasculature.

Answer 4

• Origins: medial half of clavicle, sternum and costal cartilages (1-6), anterior layer of the rectus sheath.
• Inserts onto the crest of the greater tuberosity.
• Main functions: Adduct and medially rotate the arm.
• Blood supply from the thoracoacromial artery which branches from axillary artery.
• Innervation: Medial and Lateral pectoral nerves (from brachial plexus C5-T1).

Question 5

Identify the Lateral Pectoral Nerve. From where does this branch?

Answer 5

Comes off brachial plexus (C5-C8)

Question 6

Identify the Pectoralis minor, its attachments/function, and neurovasculature.

Answer 6

• Origin: ribs 305
• Insertion: Coracoid process
• Main function: Draws the scapula forward, medially, and downward
• Blood supply from pectoral branch of the thoracoacromial trunk
• Innervation: medial pectoral nerve
• Median pectoral nerve pierces pec. minor to reach pec. major

Question 7

Identify the Medial pectoral nerve. From where does this branch?

Answer 7

Comes off brachial plexus (C8-T1). Innervates pec. major and minor

Question 8

Identify the Axillary vein and describe its course.

Answer 8

Continuation of sublcavian vein, located in axilla

Question 9

Identify the Axillary artery. From where does it branch? Identify the 3 branches of the axillary artery.

Answer 9

Continuation of subclavian artery

• Superior thoracic artery : anterior portion of thoracic wall
• Thoracoacromial artery: branches off toward deltoid
• Lateral thoracic artery: runs along anterior, lateral portion of thoracic wall