Pectoral Region Anatomy

• Pectoral region is on the front of the chest
• Pectoral region consists of structures that connect the upper limb to the anterolateral chest wall
• Mammary gland lies in the pectoral region

Surface Landmarks

• These features of the pectoral region can be seen or felt on the surface of the body

• The clavicle lies horizontally at the root of the neck, separating it from the front of the chest

• The clavicle bone is subcutaneous and palpable throughout its length

• The clavicle articulates medially with the sternum at the sternoclavicular joint, and laterally with the acromion at the acromioclavicular joint

• Both the sternoclavicular and acromioclavicular joints are palpable because of the upward projecting ends of the clavicle

• The sternoclavicular joint may be masked by the sternocleidomastoid muscle

• The jugular notch (interclavicular or suprasternal notch) lies between the medial ends of the clavicles, at the superior border of the manubrium sterni

• The sternal angle (angle of Louis) is felt as a transverse ridge about 5 cm below the jugular notch

• The sternal angle marks the manubriosternal joint

• Laterally, on either side, the second costal cartilage joins the sternum at the level of the sternal angle

• The sternal angle serves as a landmark for identification of the second rib

• Other ribs can be identified by counting downwards from the second rib

• The epigastric fossa (pit of the stomach) is the depression in the infrasternal angle

• The epigastric fossa overlies the xiphoid process, and is bounded on each side by the seventh costal cartilage

• The nipple's position is variable in females

• In males and immature females, the nipple usually lies in the fourth intercostal space just medial to the midclavicular line, or 10 cm from the midsternal line

• The position of the nipple is variable even in males

• The midclavicular line passes vertically through the middle of clavicle, the tip of the ninth costal cartilage and the midinguinal point

• The infraclavicular fossa (deltopectoral triangle) is a triangular depression below the junction of the lateral and middle thirds of the clavicle

• The infraclavicular fossa is bounded medially by the pectoralis major, laterally