What is the sternal angle and why is it clinically important?

The sternal angle (Angle of Louis) is a palpable bony landmark about 5 cm below the suprasternal notch. It corresponds to the T4–T5 disc level and marks where the 2nd ribs articulate with the sternum, making it a key reference point for counting ribs during physical examination.

How do you locate the apex beat of the heart on the chest?

The apex beat of the heart is typically found in the left 5th intercostal space. It lies approximately 9 cm from the midsternal line or just medial to the midclavicular line, making it an important landmark for cardiac auscultation.

What vertebral levels correspond to key thoracic surface landmarks?

Several thoracic landmarks align with specific vertebral levels: Suprasternal notch at T2 lower border, sternal angle at T4–T5 disc, xiphisternal joint at T9 upper border, and costal margin lowest point opposite L3. These correlations help in clinical orientation and examination.

What are the main vertical lines used to describe locations on the thorax?

Clinicians use several orientation lines to precisely describe thoracic locations: midsternal line down the middle of the sternum, midclavicular line from clavicle midpoint to midinguinal point, anterior, midaxillary and posterior axillary lines from respective axillary folds, and scapular line through the inferior angle of the scapula.

How can you identify the 7th cervical vertebra on the back?

The spine of C7 is the first prominent vertebral spine you can feel at the end of the nuchal furrow (the depression at the back of the neck). This makes it a reliable starting point for counting thoracic vertebrae during examination.

What structures form the costal margin and where is it located?

The costal margin is formed by the costal cartilages of the 7th through 10th ribs plus the free ends of the 11th and 12th ribs. Its lowest point is at the level of the 10th rib, which corresponds to the L3 vertebra.

Where is the nipple typically located in males?

In males, the nipple usually lies in the 4th intercostal space, approximately 10 cm from the midsternal line. In females, the location is more variable due to breast tissue.

Thorax Surface Anatomy – Key Landmarks for Examination

❓ Frequently Asked Questions