The Abdominal Organs
1. The coelom is the body cavity within which the viscera (internal organs) are located. The cavity is covered by a membrane called the peritoneum, which is very thin and web-like, you may need to use forceps to remove some of this membrane to see the organs clearly.
2. Locate the liver, which is a dark colored organ suspended just under the diaphragm. The liver has many functions, one of which is to produce bile, which aids in digesting fat. The liver also transforms wastes into less harmful substances. Rats do not have a gall bladder, which is used for storing bile in other animals. There are four parts to the liver:
3. The esophagus pierces the diaphragm at a spot called the hiatus and moves food from the mouth to the stomach. It is easiest to locate where it enters the stomach.
4. Locate the stomach on the left side just under the diaphragm. The functions of the stomach include food storage, physical breakdown of food, and the digestion of protein.
The outer margin of the curved stomach is called the greater curvature, the inner margin is called the lesser curvature. You can make a slit in the stomach and see what is inside it. Most of the contents should be partly digested rat food.
At each end of the stomach (on the inside) is muscular valve. The opening between the esophagus and the stomach is called the cardiac sphincter. The opening between the stomach and the intestine is called the pyloric sphincter.
5. The spleen is about the same color as the liver and is attached to the greater curvature of the stomach. It is associated with the circulatory system and functions in the destruction of blood cells and blood storage. A person can live without a spleen, but they're more likely to get sick as it helps the immune system function.
6. The pancreas is a brownish, flattened gland found in the tissue between the stomach and small intestine. The pancreas produces digestive enzymes that are sent to the intestine via small ducts (the pancreatic duct). The pancreas also secretes insulin, which is important in the regulation of glucose metabolism.
7. The small intestine is a slender coiled tube that receives partially digested food from the stomach (via the pyloric sphincter). The coils of the small intestine are held together by a membrand called the mesentery.
The small intestine has three sections: duodenum, jejunum and ileum, (Listed in order from the stomach to the large intestine.) The duodenum is recognizable as the first stretch of the intestine leading from the stomach, it is mostly straight. The jejunum and ileum are both curly parts of the intestine, with the ileum being the last section before the small intestine becomes the large intestine.
8. Locate the colon, which is the large greenish tube that extends from the small intestine and leads to the anus. The colon is also known as the large intestine. Food entering the colon from the small intestine is controlled by the ileocecal valve. The colon is where the finals stages of digestion and water absorption occurs and it contains a variety of bacteria to aid in digestion. The colon consists of five sections:
cecum - large sac where the small and large intestine meet (the ileocecal valve regulates passage of materials)
ascending colon – food travels upward.
transverse colon – a short section that is parallel to the diaphragm
descending colon – the section of the large intestine that travels back down toward the rectum.
rectum - the short, terminal section of the colon that leads to the anus. The rectum temporarily stores feces before they are expelled from the body.
Remove the intestine from below the stomach to the anus and break the mesentery to lie the intestine out in a line and measure.
2. Locate the liver, which is a dark colored organ suspended just under the diaphragm. The liver has many functions, one of which is to produce bile, which aids in digesting fat. The liver also transforms wastes into less harmful substances. Rats do not have a gall bladder, which is used for storing bile in other animals. There are four parts to the liver:
3. The esophagus pierces the diaphragm at a spot called the hiatus and moves food from the mouth to the stomach. It is easiest to locate where it enters the stomach.
4. Locate the stomach on the left side just under the diaphragm. The functions of the stomach include food storage, physical breakdown of food, and the digestion of protein.
The outer margin of the curved stomach is called the greater curvature, the inner margin is called the lesser curvature. You can make a slit in the stomach and see what is inside it. Most of the contents should be partly digested rat food.
At each end of the stomach (on the inside) is muscular valve. The opening between the esophagus and the stomach is called the cardiac sphincter. The opening between the stomach and the intestine is called the pyloric sphincter.
5. The spleen is about the same color as the liver and is attached to the greater curvature of the stomach. It is associated with the circulatory system and functions in the destruction of blood cells and blood storage. A person can live without a spleen, but they're more likely to get sick as it helps the immune system function.
6. The pancreas is a brownish, flattened gland found in the tissue between the stomach and small intestine. The pancreas produces digestive enzymes that are sent to the intestine via small ducts (the pancreatic duct). The pancreas also secretes insulin, which is important in the regulation of glucose metabolism.
7. The small intestine is a slender coiled tube that receives partially digested food from the stomach (via the pyloric sphincter). The coils of the small intestine are held together by a membrand called the mesentery.
The small intestine has three sections: duodenum, jejunum and ileum, (Listed in order from the stomach to the large intestine.) The duodenum is recognizable as the first stretch of the intestine leading from the stomach, it is mostly straight. The jejunum and ileum are both curly parts of the intestine, with the ileum being the last section before the small intestine becomes the large intestine.
8. Locate the colon, which is the large greenish tube that extends from the small intestine and leads to the anus. The colon is also known as the large intestine. Food entering the colon from the small intestine is controlled by the ileocecal valve. The colon is where the finals stages of digestion and water absorption occurs and it contains a variety of bacteria to aid in digestion. The colon consists of five sections:
cecum - large sac where the small and large intestine meet (the ileocecal valve regulates passage of materials)
ascending colon – food travels upward.
transverse colon – a short section that is parallel to the diaphragm
descending colon – the section of the large intestine that travels back down toward the rectum.
rectum - the short, terminal section of the colon that leads to the anus. The rectum temporarily stores feces before they are expelled from the body.
Remove the intestine from below the stomach to the anus and break the mesentery to lie the intestine out in a line and measure.