Spleen-Relations-Splenic Enlargement-Trauma to the Spleen

Spleen

The spleen is the largest single mass of lymphoid tissue in the body. It is oval shaped and is reddish and has a notched anterior border.
 It lies just beneath the left half of the diaphragm close to the 9th, 10th, and 11th ribs. The long axis lies along the shaft of the 10th rib, and its lower pole extends forward only as far as the midaxillary line and cannot be palpated on clinical examination .
 The spleen is surrounded by peritoneum, which passes from it at the hilum as the gastrosplenic omentum (ligament) to the greater curvature of the stomach(carrying the short gastric and left gastroepiploic vessels). The peritoneum also passes to the left kidney as the splenicorenal ligament (carrying the splenic vessels and the tail of the pancreas).

 

Relations

■■ Anteriorly: The stomach, tail of the pancreas, and left colic flexure. The left kidney lies along its medial border.

■■ Posteriorly: The diaphragm; left pleura (left costodiaphragmatic recess); left lung; and 9th, 10th, and 11th ribs.

 

Splenic Enlargement

An enlarged spleen extends downward and medially. direct downward enlargement of the organ is prevented by The left colic flexure and the phrenicocolic ligament . As the enlarged spleen projects below the left costal margin, its notched anterior border can be recognized by palpation through the anterior abdominal wall.

The spleen is situated at the beginning of the splenic vein, and in cases of portal hypertension it often enlarges from venous congestion.

Trauma to the Spleen

Although anatomically the spleen gives the appearance of being well protected, automobile accidents of the crushing or run-over type commonly produce laceration of the spleen. Penetrating wounds of the lower left thorax can also damage the spleen.

Rib and Costal Cartilage Identification- Pleural Reflections- Position and Enlargement of the Heart

Rib and Costal Cartilage Identification

When one is examining the chest from in front, the sternal angle is an important landmark. Its position can easily be felt and often be seen by the presence of a transverse ridge. The finger moved to the right or to the left passes directly onto the second costal cartilage and then the 2nd rib. All other ribs can be counted from this point. The 12th rib can usually be felt from behind, but in some obese persons this may prove difficult

Pleural Reflections

It is hardly necessary to emphasize the importance of knowing the surface markings of thepleural reflections and the lobes of the lungs. When listening to the breath sounds of the respiratory tract, it should be possible to have a mental image of the structures that lie beneath the stethoscope. The cervical dome of the pleura and the apex of the lungs extend up into the neck so that at their highest point they lie about 1 in. (2.5 cm) above the clavicle. Consequently, they are vulnerable to stab wounds in the root of the neck or to damage by an anesthetist’s needle when a nerve block of the lower trunk of the brachial plexus is being performed.

Remember also that the lower limit of the pleural reflection, as seen from the back, may be damaged during a nephrectomy. The pleura crosses the 12th rib and may be damaged during removal of the kidney through an incision in the loin

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Position and Enlargement of the Heart

The surface markings of the heart and the position of the apex beat may enable a physician to determine whether the heart has shifted its position in relation to the chest wall or whether the heart is enlarged by disease. The apex beat can often be seen and almost always can be felt. The position of the margins of the heart can be determined by percussion.