The pancreas is a recondite and unknown gland but essential for life, due to its endocrine and exocrine function. A review of its parts and functions.
The pancreas is a multifaceted organ like few others, as it has both digestive and hormonal functions, both essential for the physiological balance of the body. When we think of hormonal substances, the thyroid or pituitary usually comes to mind, structures with clear endocrine functions.
Even so, and although it may not seem like it, many other areas of the body are responsible for controlling certain metabolic processes by releasing hormones in minute amounts. This is the case, for example, of the pancreas and the adrenal glands (located above the kidneys). Of course, no matter how low their production, these molecules of a hormonal nature are essential to maintain the vital processes of the organism.
So, today we bring you the parts and functions of the pancreas, a structure of both endocrine and exocrine glandular nature. If you want to know everything about her, continue reading.
- We recommend you read: “Pancreas: what it is, parts, functions and diseases that affect it”
What is the pancreas?
The pancreas is a pear-shaped organ/gland thatmeasures approximately 15 centimeters (with a thickness of 2-3 cm) in length and weighs about 100 grams, located behind the stomach, between the spleen and the duodenum, at the level of the first and second lumbar vertebra.
Its strategic location is not a coincidence, because its proximity to the liver and appearance in the back of the abdomen allow it to be in contact with vital vascular structures, which will transport the hormones synthesized here to the different parts of the body on which they act.
It should be noted that 85% of the total tissue of this gland is exocrine (digestive slope), 10-15% represents the extracellular matrix and the blood vessels contained and only 2% corresponds to endocrine function (production and release of hormones). Despite this percentage mismatch, both functions are equally important.
Parts of the pancreas
Next, we tell you in a brief way the parts of the pancreas, in addition to the tissue nature of this gland and the liquids and hormones secreted by it. We are facing an association of glandular tissues quite simple to describe because, according to most portals consulted, 3 main parts are distinguished: head, body and tail, in addition to certain accessory structures.
1. Head
The headis the widest and thickest partof this gland on the right, placed behind the liver and partially surrounding the duodenum, the first portion of the small intestine. Therefore, it is considered to be within the cluster called “duodenal loop”.
2. Unciform process
The part of the gland that bends back to and below the head of the pancreas. It is posterior to the superior mesenteric vessels, that is, the set of vessels that flow into the second odd branch of the aorta artery.
3. Neck
It is simply thearea of connection between the body and the head. It is anterior to the superior mesenteric vessels already named and after it the portal vein is created.
4. Body
The body is located behind the liver and small intestine. It is the central part of the pancreas, and has a characteristic prismatic shape of 3 faces. It continues posterior to the stomach and develops to the left, ascending slightly compared to the head.
5. Tail
The prolongation of the body extending to the spleen. It draws attention with respect to the rest of the dissected structures, since it is the only part of the intraperitoneal pancreas, that is, it is located within the peritoneal cavity delimited by the membranes of the peritoneum. It is the narrowest part of the pancreas and is in direct contact with the back of the stomach and spleen.
6. Wirsung Conduit
Following the characteristic physiology of this gland, arising from the tail of the pancreas we find the Wirsung duct, which crosses the body and head to reach the duodenum, meeting with the common bile duct of the gallbladder. The function of this channel is clearly exocrine, as it is responsible for gathering and releasing pancreatic juices to the duodenum to perform their digestive function.
7. Histological section
Although it is not a part in itself of the pancreas, to understand its functionality it is necessary to distinguish the various cell types present here.
7.1. Exocrine portion
As we have said, 80-85% of this gland is composed of cells of exocrine nature, that is, those that synthesize the pancreatic juices, which will be collected by the Wirsung duct and will flow into the duodenum. The histological unit with this functionality is the pancreatic acinus, a set of cells responsible for producing this fluid, composed mainly of water, enzymes, bicarbonate and minerals.
We can distinguish two main cell types in this section: acinar cells and centroacinar cells. The first are responsible for synthesizing the most important enzymes with digestive function per se, among which are amylase and lipase. The function of these is to chemically break down ingested fats and proteins into small portions that can be absorbed by the intestine. On the other hand, centroacinar cells synthesize a buffer rich in bicarbonate, which allows the action of the enzymes described.
7.2. Endocrine portion
On the other side of the coin, the endocrine portion of the pancreas accounts for a tiny 2% of its total mass. Despite this, its functionality is practically unfathomable. Next, we make a brief tour of the cell types included here:
- Alpha cells: synthesize and release glucagon, a hormone that stimulates glucose production and the glycemic index of the individual.
- Beta cells: they produce and release the famous hormone insulin, which is essentially involved in the metabolism of circulating carbohydrates.
- Delta cells: release somatostatin, a hormone essential for the process of intestinal motility and regulation in nutrient metabolism.
- Epsilon cells: produce ghrelin, a hormone involved in the sensation of hunger and other gastric processes.
- PP cells: release pancreatic peptide, a substance that modulates the exocrine portion of the pancreas.
The functional unit of this entire cellular conglomerate is the islet of Langerhans, an accumulation of the cells already named with a specific function and typology. Thus, we can conclude that these cell bodies are not distributed by the endocrine tissue homogeneously, but are grouped according to specialty in each of these islets.
8. Pancreatic juice
Again, we are not facing a part as such, but we can not leave this space without at least referring to pancreatic juice, product of the exocrine activity of the pancreas and the PP modulating cells mentioned above.
As we have already said, this liquid contains an enzymatic portion of vital importance, because it includes the enzymes amylase, lipase and othersthat are included in 4 different groups: lipolytic, proteolytic, glycolytic and nucleolytic. The final “lytic” part of these terms is not anecdotal, since the function of each of these enzymes is to shell proteins, lipids, carbohydrates and nuclear elements so that the basic molecules that make them up can be absorbed by the intestine.
The pancreas secretes, daily, about 1,500 – 3,000 milliliters of this fluid, which flows into the duodenum. Among the most important functions of the pancreas, we find the following:
- Neutralize and alkalize the chyle coming from the stomach, providing the optimal pH so that the enzymes in the duodenum can act. This is done by the centroacinar cells, which produce the buffer described above.
- Provide the enzymes necessary for the digestion of fats, releasing simple fatty acids and glycerol to the intestinal lumen.
- Provide enzymes that metabolize proteins, thus giving rise to the free amino acids that compose them.
- The digestion of complex carbohydrates (such as starch or glycogen), releasing glucose, which is a nutrient source of energy essential for life.
- Provide the enzymes necessary for the digestion of nucleic acids present in the nucleus of cells, thus releasing nucleotides.
As you may have seen, the functionality of this fluid goes far beyond a simple facilitation of the task to the small intestine.
Summary
In short, we can say thatthe pancreas is an organ of a very simple glandular nature at the anatomical level, but whose functionality is almost unfathomable in afew lines. Yes, the exocrine part is quite direct, because its purpose is to perform part of the digestion, but the hormonal portion of this gland performs a huge amount of functions.
Undoubtedly, spaces like this make it clear that no body tissue is useless in human physiology, however small and unimportant it may seem in the first instance. In the human body, every cell counts.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.