Chapter 21: The Thorax and Abdomen

OBJECTIVES

When you finish this chapter you will be able to:

• Describe the anatomy of the thorax and abdomen.

• Identify the location and function of the heart and lungs.

• Indicate the location and function of the abdominal viscera.

• Explain the techniques for assessing thoracic and abdominal injuries.

• Differentiate between various injuries to the structures of the thorax.

• Recognize various injuries and conditions in structures of the abdomen.

INTRODUCTION

This chapter covers injuries to the thorax and abdomen. In an athletic environment, injuries to the thorax and abdomen have a lower incidence than injuries to the extremities and the spine. However, unlike the musculoskeletal injuries to the extremities discussed to this point, injuries to the heart, lungs, and abdominal viscera can be potentially serious and even life threatening if not recognized and managed appropriately.² It is essential to be familiar with anatomy and the more common injuries seen in the abdomen and thorax (Figure 21–1).

ANATOMY OF THE THORAX

The thorax is that portion of the body commonly known as the chest, which lies between the base of the neck and the diaphragm. It is contained within the thoracic vertebrae and the twelve pairs of ribs that give it its shape (Figure 21–2). Its main function is to protect the vital respiratory and circulatory organs and to assist the lungs in inspiration and expiration during the breathing process.²⁷

The ribs are flat bones that are attached to the thoracic vertebrae in the back and to the sternum in the front. The upper seven ribs are called sternal, or true, ribs, and each rib is joined to the sternum by a separate costal cartilage. The eighth, ninth, and tenth ribs (false ribs) have cartilages that join each other and the seventh rib before uniting with the sternum. The eleventh and twelfth ribs (floating ribs) remain unattached to the sternum but do have muscle attachments. The intercostal muscles, which lie between the ribs, and the diaphragm muscle, which separates the thoracic cavity from the abdominal cavity, function in inspiration and expiration²⁷ (Figure 21–3) (Table 21–1).