This is the first of a series of articles documenting the roles that various organs play in the human body and what can go wrong with those organs. I have chosen to begin with the pancreas because it performs many, many important functions in the human body.
The pancreas is both an exocrine and endocrine organ. Endocrine glands release hormones into the blood in order to cause an effect in some part of the body. For example, the pancreas releases insulin in response to high blood sugar and the adrenal glands that sit atop the kidney secrete adrenalin, the “fight or flight” hormone. Exocrine glands release enzymes through ducts and include mammary glands, salivary glands, sweat glands, and glands that secrete digestive enzymes into your stomach and intestine. A main difference is that the exocrine glands release fluids that will exit the body, either through the digestive tract, the skin, the nipple or the mouth, whereas endocrine glands are an internal messaging system.
Where is the pancreas? It is located behind the liver and mostly on the right hand side of your body.
What hormones and enzymes do the pancreas secrete and what roles do they play in the human body? The pancreas make two competing endocrine hormones that play an important role in diabetes, hypo and hyperglycemia. Hypo refers to a low level, “glyc” refers to glucose and “emia” always refers to blood. So hypoglycemia literally means low sugar in the blood. Hyperglycemia is high blood sugar. I think of hyper kids to remember an excess of something. Both hypo and hyper can be used to describe the state of many organs in the body. Hypo and hyperthyroidism, hypo and hypercalcemia (low or high blood calcium), hyperhidrosis (excess sweating).
The pancreas makes insulin, the hormone responsible for controlling the amount of glucose in the blood. If you eat a caramel apple, your blood will temporarily be high in glucose until the insulin facilitates metabolism. The pancreas also make glucagon (I think of glucose being gone from the blood to remember this). Glucagon is released when your blood sugar drops too low and stimulates your liver to convert stored glycogen to glucose for the blood to take to cells in your body. Remember that the glycogen was stored by the liver when our body produced insulin in response to eating a food high in sugar. Both of these hormones come from the endocrine part of the pancreas known as the islets of Langerhans. These islets are made up of alpha and beta cells. Alpha cells secrete glucagon and beta cells secrete insulin.
The exocrine structures in the pancreas are called Pancreatic acini. There are four digestive enzymes that are secreted from these acini into the digestive tract: pancreatic lipase helps in the digestion of fats (lipase stems from lipid and anything with “ase” at the end will be some sort of enzyme – that goes for the whole body). Specifically, pancreatic lipase emulsifies fat (a fancy word to describe making the fat globules smaller so that the fat can be taken up by the blood). Pancreatic amylase breaks down starch into sugar; starches are simply long chains of sugars. Trypsin breaks down proteins into peptide chains and Chymotrypsin breaks down peptide chains into amino acids.
Knowing all of this, you can see why having a problem with you pancreas can quickly become deadly. What can go wrong? Diabetes is a condition where insulin is either non existant or inadequate in supply. Type 1 diabetes, the beta cells in the pancreas have been destroyed and you are no longer able to make insulin. Daily injections of insulin are necessary to digest sugar and sugar intake must be monitored closely. Type 2 diabetes is a condition that usually develops later in life and is characterized by low insulin levels and high blood sugar. This disease develops as a result of both a genetic predisposition, and lifestyle factors that contribute to the body building up a tolerance to insulin so that higher and higher levels are needed to maintain a normal blood sugar. Eventually the pancreas can’t keep up with demand and unless a significant change in lifestyle is made. Sometimes Type 2 diabetics will need to manage the disease with insulin injections.
Pancreatitis is literally an inflammation of the pancreas; the term “itis” refers to something that is inflammed. It can either be acute or chronic. Acute pancreatitis has a sudden onset and needs immediate medical intervention. It is most often caused by alcoholism and gallstones. Chronic pancreatitis is usually caused by long term alcohol abuse. A quarter of cases have no known cause.
Adenocarcinomas are the most common form of pancreatic cancer. They are neoplasms of the glandular tissue; the tissue responsible for secreting digestive enzymes. This is a particularly deadly form of cancer. Less than 5% of individuals are alive after 5 years and remission is extremely rare.
Cystic fibrosis, in addition to all of the other nasty effects it has on the body, causes cysts to form in the pancreas, resulting in permanent damage and painful, chronic inflammation.
There are other things that can go wrong with your pancreas; I have just touched on the main problems. I don’t want to contribute to hyperchondria!