Surface anatomy and surface markings-The Thorax

The experienced clinician spends much of his working life relating the

surface anatomy of his patients to their deep structures

The following bony prominences (BULGES) can usually be palpated (EXAMINED BY TOUCH) in the living subject (matching vertebral levels are given in brackets):

•◊◊superior angle of the scapula (SHOULDER BLADE) (T2);

•◊◊upper border of the manubrium sterni(BROAD UPPER STRENUM), the suprasternal notch (fig 1.2)(DIP IN THE STERNUM)(T2/3);

•◊◊spine of the scapula (T3);

•◊◊sternal angle (of Louis)— the transverse ridge at the manubrio-sternal

Junction(BUMP AT STERNAL JUNCTION) (T4/5);

•◊◊inferior angle of scapula (T8);

•◊◊xiphisternal joint (LOWEST JOINT IN STERNUM)(T9);

•◊◊lowest part of costal margin—10th rib (the subcostal line passes through

L3).

Note from Fig. 1 that the manubrium(BROAD UPPER STERNUM) corresponds to the 3rd and 4th

Thoracic (PART OF BODY BETWEEN HEAD AND ABDOMEN) vertebrae and overlies the aortic arch, and that the sternum corresponds to the 5th to 8th vertebrae and neatly overlies the heart.

Since the 1st and 12th ribs are difficult to feel, the ribs should be enumerated (COUNTED)

from the 2nd costal cartilage (CONNECTS STERNUM AND RIBS), which articulates with the sternum at the angle of Louis.

The spinous processes (LUMPY BITS) of all the thoracic vertebrae can be palpated in

the midline posteriorly (FROM THE BACK TO THE FRONT), but it should be remembered that the first spinous process that can be felt is that of C7 (the vertebra prominens).

The position of the nipple varies considerably in the female, but in the male it usually lies in the 4th intercostal space (BETWEEN THE RIBS) about  10cm from the midline. The apex beat (BEAT OF HEART FELT OVER APEX), which marks the lowest and outermost point at which the cardiac impulse can be palpated, is normally in the 5th intercostal space 9cm from the midline (just below and medial (TO THE CENTRE) to the nipple).

The trachea (WINDPIPE) is palpable in the suprasternal notch (fig. 1.2) midway between the heads of the two clavicles.

Fig. 1.2 the suprasternal notch-the dip imbetween the two clavicles and top of the sternum