1. Esophagus. 2. Stomach. 3. Liver raised, showing the under surface. 4. Duodenum. 5. Small intestines, consisting of—6. Jejunum and ilium. 7. Colon. 8. Urinary bladder. 9. Gall bladder. 10. Abdominal muscles divided and reflected.] 662. The first portion of the small intestine is termed the duodenum (fig. CLXVII. 3). It is about twelve inches in length, and, unlike the stomach, which is capable of considerable motion, it is closely tied down to the back by the peritoneum, which imperfectly covers it. The rest of the small intestine is divided into two portions—the upper two-fifths of which are termed jejunum, and the three lower ilium. 663. The duodenum, the chamber which receives the chyme from the pylorus, is a second stomach, which carries on the process commenced in the first. It is assisted in the performance of its function by two organs of considerable magnitude, the pancreas and the liver. 664. The pancreas is a conglomerate gland (fig. CLXXII. 5), of an elongated form, placed in the epigastric region, lying transversely across it, immediately behind the stomach (fig. CLXXII. 1), and resting upon the spinal column (fig. CLXXII. 5). Its right extremity is attached to the duodenum (fig. CLXXII. 9), and its left to the spleen (fig. CLXXII. 4). In external appearance it resembles the salivary glands, but it is of much larger size, and its weight, from four to six ounces, is three times greater than that of all the salivary glands together. It secretes a peculiar fluid called the pancreatic juice, which is carried into the duodenum by a tube named the pancreatic duct (fig. CLXVII. 7), which opens into the duodenum about four or five inches from its pyloric end (fig. CLXVII. 2). [Illustration: Fig. CLXXII. 1. Stomach raised. 2. Under surface of liver. 3. Gall bladder. 4. Spleen. 5. Pancreas. 6. Kidneys. 7. Ureters. 8. Urinary bladder. 9. Portion of intestine called duodenum. 10. Portion of intestine called rectum. 11. Aorta.] 665. The liver, the largest and heaviest gland in the body, weighing about four pounds, is placed chiefly in the right hypochondriac region (fig. CLXXI. 3); but a portion of it extends transversely across the epigastric, into the left hypochondriac region (figs. CV. and CVII. 3). Its upper surface is in contact with the diaphragm (fig. LX. 6, b); its under surface with the pyloric extremity of the stomach (fig. LX. 7), and its margin can be felt under the edges of the ribs of the right side.