WKI Sales Training Feb 2014

3

C H A P T E R

TheThorax

The heart and lungs are fragile organs, and the main func- tion of the thorax is to house and protect them. The protec- tive function of the thoracic wall is combined with mobility to accommodate volume changes during respiration. These two dissimilar functions, protection and flexibility, are ac- complished by the alternating arrangement of the ribs and intercostal muscles. The superficial fascia of the thorax contains the usual elements that are common to superficial fascia in all body regions: blood vessels, lymph vessels, cutaneous nerves, and sweat glands. In addition, the superficial fascia of the anterior thoracic wall in the female contains the mammary glands, which are highly specialized organs unique to the superficial fascia of the thorax. The surface anatomy of the thorax can be studied on a living subject or on the cadaver. Turn the cadaver to the supine position and palpate the following structures (FIG. 3.1) : • Jugular notch (suprasternal notch) • Clavicle • Acromion of the scapula • Manubrium • Sternal angle • Body of the sternum • Xiphoid process • Costal margin • Anterior axillary fold (lateral border of the pectoralis major muscle) SURFACE ANATOMY [G 2; L 160; N 175; C139]

Jugular notch

Clavicle

Acromion

Manubrium

Sternal angle

Anterior axillary fold Body of sternum Xiphisternal joint Xiphoid process

Seventh costal cartilage

Costal margin

FIGURE 3.1 Surface anatomy of the anterior thoracic wall.

SKELETON OF THE THORAX If you have previously dissected the back, review the parts of a thoracic vertebra . If you have not dissected the back, you must study the vertebrae now. Turn to pages 6 to 8, complete that exercise, and return to this page. Refer to a skeleton. Examine a rib from the midthorax level and identify (FIG. 3.2) : [G 15; L 164; N 180; R 197; C 142]

• Head • Neck • Tubercle

• Costal angle • Shaft (body) • Costal groove

ATLAS REFERENCES: G = Grant’s Atlas , 13th ed., page number L = LWW Atlas of Anatomy , 1st ed., page number N = Netter’s Atlas , 5th ed., plate number R = Color Atlas of Anatomy , 7th ed., page number C = Clemente’s Atlas , 6th ed., plate number

On an articulated skeleton, note the following features: • The first rib is the highest, shortest, broadest, and most sharply curved rib.

63

Tank_CH03.indd 63

01/04/12 12:01 AM