Differences Between the Small and Large Intestine- External Differences--Internal Differences-Liver Trauma-Liver Biopsy-Subphrenic Spaces-

Differences Between the Small and Large Intestine
  External Differences

■■ The small intestine has no fatty tags attached to its wall. The large intestine has fatty tags, called the appendices epiploicae.

■■ The small intestine is mobile( but not the duodenum), whereas the ascending and descending parts of the colon are fixed.

■■ The caliber of the full small intestine is smaller than that of the filled large intestine.

■■ The small intestine (with the exception of the duodenum) has a mesentery that passes downward across the midline into the right iliac fossa.

■■ The longitudinal muscle of the small intestine forms a continuous layer around the gut. In the large intestine (with the exception of the appendix), the longitudinal muscle is collected into three bands, the teniae coli

■■ The wall of the small intestine is smooth, whereas that of the large intestine is sacculated

Internal Differences

■■ The mucous membrane of the small intestine has permanent folds, called plicae circulares, which are absent in the large intestine.

■■ The mucous membrane of the small intestine has villi, which are absent in the large intestine.

■■ Aggregations of lymphoid tissue called Peyer’s patches are found in the mucous membrane of the small intestine; these are absent in the large intestine.

Liver Trauma

 Because The liver is a soft organ, it is a friable structure enclosed in a fibrous capsule. Fractures of the lower ribs or penetrating wounds of the thorax or upper abdomen are common causes of liver injury  because Its close relationship to the lower ribs must be emphasized.. Blunt traumatic injuries from automobile accidents are also common, and severe hemorrhage accompanies tears of this organ. Because anatomic research has shown that the bile ducts, hepatic arteries, and portal vein are distributed in a segmental manner, appropriate ligation of these structures allows the surgeon to remove large portions of the liver in patients with severe traumatic lacerations of the liver or with a liver tumor. (Even large, localized carcinomatous metastatic tumors have been successfully removed.)

 

Liver Biopsy

Liver biopsy is a common diagnostic procedure.  And to reduce the size of the costodiaphragmatic recess and the likelihood of damage to the lung the patient must  holding his or her breath in full expiration—a needle is inserted through the right 8th or 9th intercostal space in the midaxillary line. The needle passes through the diaphragm into the liver, and a small specimen of liver tissue is removed for microscopic examination.

 

Subphrenic Spaces

The important subphrenic spaces and their relationship to the liver are described on page 163. Under normal conditions, these are potential spaces only, and the peritoneal surfaces are in contact. An abnormal accumulation of gas or fluid is necessary for separation of the peritoneal surfaces. The anterior surface of the liver is normally dull on percussion. Perforation of a gastric ulcer is often accompanied by a loss of liver dullness caused by the accumulation of gas over the anterior surface of the liver and in the subphrenic spaces.

Surface Landmarks of the Abdominal Viscera-Gallbladder-Spleen-Liver-Pancreas-Kidneys-Stomach-Aorta

Surface Landmarks of the Abdominal Viscera

Gallbladder

The gallbladder is a pear-shaped sac,The fundus of the gallbladder lies opposite the tip of the right ninth costal cartilage—that is, where the lateral edge of the right rectus abdominis muscle crosses the costal margin

 

Spleen

It lies in the left upper quadrant and lies under cover of the 9th, 10th, and 11th ribs. Its long axis corresponds to that of the 10th rib, and in the adult it does not normally project forward in front of the midaxillary line. In infants, the lower pole of the spleen may just be felt

Liver

The liver is a large organ that occupies the upper part of the abdominal cavity is covered under  the lower ribs, and most of its bulk lies on the right side.
In infants, until about the end of the third year, the lower margin of the liver extends one or two fingerbreadths below the costal margin. In the adult who is obese or has a welldeveloped right rectus abdominis muscle, the liver is not palpable. In a thin adult, the lower edge of the liver may be felt a fingerbreadth below the costal margin. It is most easily felt when the patient inspires deeply and the diaphragm contracts and pushes down the liver.

 

Pancreas

The pancreas lies across the transpyloric plane. The head lies below and to the right, the neck lies on the plane, and the body and tail lie above and to the left.

 

Kidneys

the left kidney lies at a slightly  higher level than The right kidney (because of the bulk of the right lobe of the liver), and the lower pole can be palpated in the right lumbar region at the end of deep inspiration in a person with poorly developed abdominal muscles. Each kidney moves about 1 in. (2.5 cm) in a vertical direction during full respiratory movement of the diaphragm. The normal left kidney, which is higher than the right kidney, is not palpable. On the anterior abdominal wall, the hilum of each kidney lies on the transpyloric plane, about three fingerbreadths from the midline. On the back, the kidneys extend from the 12th thoracic spine to the 3rd lumbar spine, and the hili are opposite the 1st lumbar vertebra

Stomach

The stomach is a dilated part of the alimentary canal between the esophagus and the small intestine ,The cardioesophageal junction lies about three fingerbreadths below and to the left of the xiphisternal junction (the esophagus pierces the diaphragm at the level of the10th thoracic vertebra).

The pylorus lies on the transpyloric plane just to the right of the midline. The lesser curvature lies on a curved line joining the cardioesophageal junction and the pylorus. The greater curvature has an extremely variable position in the umbilical region or below.

Aorta

The aorta lies in the midline of the abdomen and bifurcates below into the right and left common iliac arteries opposite the 4th lumbar vertebra—that is, on the intercristal plane. The pulsations of the aorta can be easily palpated through the upper part of the anterior abdominal wall just to the left of the midline.