Pectoral Region Anatomy Overview

Pectoral Region Overview

• The pectoral region encompasses the anterior chest wall, including the breast (in females) and associated muscles and structures.
• It's crucial for upper limb movement, respiration, and supporting the breast tissue.
• This region provides attachment sites for various muscles that facilitate arm movement.

Muscles of the Pectoral Region

• Pectoralis major: A large, fan-shaped muscle that covers most of the anterior chest wall.
  • It has three functional parts: clavicular, sternocostal, and abdominal.
  • Functions primarily in flexion, adduction, and medial rotation of the humerus.
• Pectoralis minor: A thin, triangular muscle lying beneath the pectoralis major.
  • Originates from the ribs and inserts on the scapula.
  • Assists in scapular protraction, downward rotation, and upward tilt.
• Subclavius: A small muscle located inferiorly and medially to the clavicle.
  • Stabilizes the clavicle.
  • Its primary function is to prevent the clavicle from being displaced superiorly.
• Serratus anterior: Though primarily associated with the scapula, portions of this muscle reside in the pectoral region.
  • Located on the lateral anterior chest wall.
  • Its action is crucial for scapular protraction and upward rotation.

Blood Supply and Innervation

• Blood supply primarily arises from the branches of the axillary artery, including the pectoral branches.
• Innervation: The muscles of the pectoral region are innervated by branches of the brachial plexus, particularly the medial and lateral pectoral nerves.

Breast Anatomy (Female)

• Cooper's ligaments: Dense connective tissue bands that support the breast tissue and maintain its shape.
• Lactiferous ducts: These ducts carry milk from the alveoli to the nipple during lactation.
• Lobules: These structures are the functional units of the breast, producing milk.
• Areola: The pigmented area surrounding the nipple.
• Nipple: The central projection of the breast, containing the openings of the lactiferous ducts.

Important Clinical Considerations

• Breast cancer: A common malignancy arising from the breast tissue.
• Pectoral muscle injuries: These injuries can occur through trauma or overuse, resulting in pain and functional impairments.
• Pectoral region anatomical variations: These variations can influence surgical approaches and outcomes.

Landmarks

• Clavicle: The anterior and medial border is visible on the surface of the thoracic region. It forms part of the connection between the upper limb and trunk.
• Sternum: The bony structure in the central anterior chest.
• Ribs: The bony structures of the thorax that articulate with the sternum and vertebral column.
• Nipple: Important dermatological landmark, often used for breast examinations.

Functional Significance

• Movement of the arm and shoulder girdle.
• Breathing mechanics (indirectly through muscle attachments).
• Support for the breast tissue.
• Protection of underlying thoracic organs.

Clinical Applications

• Breast palpation is vital during health checkups.
• Musculoskeletal injuries (e.g. fractures of the clavicle or ribs) can impact this region.
• Understanding pectoral anatomy is necessary for proper surgical procedures (breast surgeries, shoulder surgeries).
• Physiotherapeutic interventions for musculoskeletal conditions in this region.