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Lab 7: Vertebrate Anatomy: Difference between revisions
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→Digestive, Urogenital, Circulatory and Respiratory Anatomy of the Fetal Pig
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You may need to drain and/or rinse extraneous fluids from the abdominal cavity.<BR> | You may need to drain and/or rinse extraneous fluids from the abdominal cavity.<BR> | ||
In the abdominal cavity the <u>liver</u> is the large, dark organ that dominates the anterior abdomen. It is divided into five lobes, and is the primary site of conversion of glucose into glycogen (a carbohydrate storage molecule) and the reverse of this process, the breakdown of glycogen into glucose. It is also the site of the synthesis of bile, a product that aids in the digestion of fats by emulsifying them. Bile is stored in the <u>gall bladder</u>, a sac located beneath the right central lobe of the liver, from which it exits via a series of ducts to the small intestine.<br><br> | In the abdominal cavity the <u>liver</u> is the large, dark organ that dominates the anterior abdomen. It is divided into five lobes, and is the primary site of conversion of glucose into glycogen (a carbohydrate storage molecule) and the reverse of this process, the breakdown of glycogen into glucose. It is also the site of the synthesis of bile, a product that aids in the digestion of fats by emulsifying them. Bile is stored in the <u>gall bladder</u>, a sac located beneath the right central lobe of the liver, from which it exits via a series of ducts to the small intestine.<br><br> | ||
The <u>stomach</u> lies on the left side of the upper abdomen. The esophagus transports food to the stomach, which is a major site of protein digestion. Caudally, the stomach empties the semi-digested chyme into the <u>small intestine</u>. The most anterior part of the small intestine, the <u>duodenum</u>, receives bile synthesized by the liver and digestive enzymes from the <u>pancreas</u>. The pancreas is a lobulated structure somewhat lighter in color than the neighboring intestines. The main body of the pancreas lies in the loop of the duodenum. Carbohydrates, fats, and proteins are all digested in the small intestine. Although the long narrow <u>spleen</u> is not a digestive organ, its position, wedged between the stomach and the diaphragm, make discussion of it appropriate. In the pig and many other mammals, the spleen is quite muscular and can eject large quantities of blood into the circulation to correct sudden blood loss. The human spleen is not muscular so it cannot contract nor store a large quantity of blood. It functions as an important part of the immune system, but is not an essential organ, meaning humans can live without one if it must be removed due to trauma or disease. <br><br> | The <u>stomach</u> lies on the left side of the upper abdomen. Food enters the mouth, travels through the pharynx, and when swallowed enters the <u>esophagus</u>. The esophagus is an easily compressible tube that lies immediately dorsal to the trachea. The esophagus traverses the thoracic cavity, and then passes through an opening in the diaphragm to enter the abdominal cavity. You will find these organs later in the dissection.<br> | ||
The esophagus transports food to the stomach, which is a major site of protein digestion. Caudally, the stomach empties the semi-digested chyme into the <u>small intestine</u>. The most anterior part of the small intestine, the <u>duodenum</u>, receives bile synthesized by the liver and digestive enzymes from the <u>pancreas</u>. The pancreas is a lobulated structure somewhat lighter in color than the neighboring intestines. The main body of the pancreas lies in the loop of the duodenum. Carbohydrates, fats, and proteins are all digested in the small intestine. Although the long narrow <u>spleen</u> is not a digestive organ, its position, wedged between the stomach and the diaphragm, make discussion of it appropriate. In the pig and many other mammals, the spleen is quite muscular and can eject large quantities of blood into the circulation to correct sudden blood loss. The human spleen is not muscular so it cannot contract nor store a large quantity of blood. It functions as an important part of the immune system, but is not an essential organ, meaning humans can live without one if it must be removed due to trauma or disease. <br><br> | |||
Follow the course of the small intestine, which is supported by a membrane, the <u>mesentery</u>. The end of the small intestine joins the <u>large intestine</u> (colon), which is noticeably larger in cross section. At the juncture a short blind sac, the <u>caecum</u>, is formed. The large intestine is a site of water re-absorption. Follow its course through the posterior abdomen to its terminal portion, the <u>rectum</u>. You will not be able to see the rectum until you remove the pubic bone later in the dissection. Wastes leave the digestive system via the anus directly below the rectum.<br><br> | Follow the course of the small intestine, which is supported by a membrane, the <u>mesentery</u>. The end of the small intestine joins the <u>large intestine</u> (colon), which is noticeably larger in cross section. At the juncture a short blind sac, the <u>caecum</u>, is formed. The large intestine is a site of water re-absorption. Follow its course through the posterior abdomen to its terminal portion, the <u>rectum</u>. You will not be able to see the rectum until you remove the pubic bone later in the dissection. Wastes leave the digestive system via the anus directly below the rectum.<br><br> | ||
