Anatomy And Physiology

Anatomy Physiology

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The pancreas in humans is an indispensable  organ which which without it we cannot survive due to its important function in maintaining homeostasis in the body and in particular its role in sugar metabolism and in the digestion process in the small intestine.  The pancreas is a unique organ in the body because it is an endocrine as well as an exocrine organ. 

The exocrine pancreas function by secreting enzymes into the duodenum that participate in the digestion process of proteins and carbohydrates in addition to digesting lipids.  proteins digesting enzymes are called peptidases and function by digesting the proteins to amino acids.  In addition to this important function the stomach also helps in the digestion process by secreting the enzyme pepsin.  Thus partial digestion of proteins occur in the stomach in addition to itsm main site of digestion the intestine.

The second type of molecules that are digested with the help of pancreatic secretion is the carbohydrates.  These carbohydrates are digested with the help of the enzyme amylase which is specific for carbohydrates that are digested to its sugar units including glucose.  The degradation of carbohydrates in the small intestine is partially compensated by the digestion of food in the mouth through the secretion of amylase by the salivary glands which aid in the digestion process.  Chewing also helps in the digestion process.

The third type of enzymes that the pancreas secrete is the lipase enzyme.  This enzyme is specific for lipids digestion and in particular the trigylcerides molecules that are degraded to glycerol and fatty acids.  Lipase enzyme is a unique enzyme that is secreted only by the pancreatic tissue cells. 

In the case of pancreatic failure in which secretion of these enzymes is impaired the degradation of lipids is stopped in the small intestine.  As a result lipids start to appear in the feces or stool.  A sign that lipids are in the stool is to see a floating stool on the water surface.  In addition to the presence of fat in the stool there is also a constipation accompanying this disorder in many cases.  This is due to maldigestion of food in the intestine.

The treatment to pancreatic failure is to correct the cause such as opening a blocked canal of the pancreas or by administration of supplementary amount of enzymes such as the commercially available drug that is called pancreatin.  Blockage of the head of the pancreas can occur in pancreatic cancer of the head of the pancreas. 

The opening in which the secretion of the pancreas in addition to bile from the gallbladder is called the ampulla of vater.  This opening can be blocked due to an inflammation of the head of the pancreas or due to a cancer of the pancreas which can lead to the development of jaundice and pancreatic failure.  The blockage also can cause a retention of the pancreatic enzymes and subsequent autodigestion leading to pancreatitis.  One of the symptoms of pancreatitis and cancer of the pancreas in the development of jaundice or yellowing of the skin color.

The endocrine pancreas is specialized in secreting several hormones the most important of which is insulin and glucagon.  These two hormones are important due to the regulation of the levels of the sugar glucose in the blood.  Insulin is being secreted in the case of hyperglycemia and glucagon is secreted in the case of hypoglycemia. 

Tumours of the islets cells of the pancreas can oversecrete either one of these two hormones depending on the type of cells that is involved in the tumour.  Insulinoma is a tumour of the endocrine pancreas in which it oversecretes the hormone insulin with a result of the development of hypoglycemia. 

Glucagonoma is another type of tumour that also affect the islet cells of the pancreas that are specialized in secreting the hormone glucagon.  It oversecretes this hormone thus leading to diabetes and hyperglycemia. 

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