Skip to Main Content


Big Picture


The clavicle and parts of the thoracic cage provide prominent surface landmarks. Directional terms are used to help orient the reader to the thorax. The cutaneous innervation of the anterior portion of the thoracic wall is from lateral and anterior cutaneous nerves via ventral rami, forming a segmental dermatomal pattern.


Bony Landmarks


Palpable bony landmarks and reference lines are important to use for anatomic orientation as well as a guide to locate deep structures. You should become familiar with the following structures of the anterior portion of the thoracic wall (Figure 2-1A; Table 2-1):


  • Clavicles. Course transversely along the superior portion of the chest wall from the manubrium to the acromion of the scapula and, therefore, are easily palpable. However, the clavicle, overly rib 1, which makes rib 1 impalpable.
  • Jugular notch of the sternum. Located between the medial ends of the clavicles.
  • Sternal angle (of Louis). Articulation between the manubrium and sternal body. The sternal angle serves as the location for the articulation of rib 2 with the sternum at the T4–T5 vertebral level. The sternal angle is often visible and palpable and serves as an important surface landmark for several underlying structures.
  • Xiphoid process. An inferior pointed projection of the sternal body. The xiphoid process lies at the level of the T9 vertebral body.
  • Costal margins. Formed by costal cartilages 7–10.

Figure 2-1
Graphic Jump Location

A. Surface anatomy of the anterior thoracic wall demonstrating bony landmarks and directional terms. B. Cutaneous nerves revealing dermatomal pattern of the thorax.

Table Graphic Jump Location
Table 2-1. Important Vertebral Landmarks of the Thorax

Directional Terms


The following imaginary vertical lines provide anatomic and clinical descriptions for orientation (Figure 2-1A):


  • Midsternal line. Dropped through the center of the sternum. It is a component of the median plane.
  • Midclavicular line. Dropped through the middle of the clavicle, just medial to the nipple.
  • Anterior axillary line. Dropped through the anterior axillary fold formed by the pectoralis major muscle.
  • Midaxillary line. Dropped through the middle of the axilla, along the lateral border of the thoracic wall. The midaxillary line is bounded by the anterior axillary fold ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.