What is the pancreas?
The pancreas is a large, long, flat gland located transversely at the top and back of the abdominal cavity.
In young subjects it reaches a weight of about 80-100 grams, which tends to decrease with advancing age; the overall length is around 15 centimeters.
Anatomy
The head represents its thickest and thickest part and makes contact with the duodenal loop.
The body, slightly oblique from bottom to top, represents the intermediate segment and is placed frontally with respect to the aorta and the vena cava.
Finally, the tail of the pancreas takes on a relationship with the hilum of the spleen and represents the thinned section with which this glandular organ ends.
Functions of the Pancreas
The pancreas has a dual function, endocrine on the one hand and exocrine on the other. The first term refers to its ability to secrete the hormones it synthesizes into the bloodstream, while the exocrine function consists in the production of digestive enzymes to be introduced into the bloodstream. digestive tract.
Exocrine pancreas
The pancreatic acini represent the anatomical areas responsible for exocrine secretion; within them we find particular cells, called acinar, which produce digestive enzymes in an inactive form, and then pour them, under the influence of certain physiological stimuli, into the duodenum.
Once here, after traveling through a tree of converging channels in the main pancreatic duct (Wirsung's duct) and accessory pancreatic (Santorini's duct), these enzymes are activated by other proteins and can finally carry out their chemical action.
The various digestive enzymes produced by the pancreas can be classified, based on their activity, in different categories, which together give rise to the so-called pancreatic juice:
- AMYLASE: they transform food starch into a mixture of simple sugars (disaccharides, maltose, glucose) which will then be absorbed in the intestinal mucosa.
- CHIMOTRIPSIN, TRIPSIN, CARBOXYPEPTIDASE: hydrolyze the peptide bonds present inside the protein structures, fragmenting them into the individual amino acids that compose them.
- LIPASE: assisted by bile and colipase enzymes, they catalyze the hydrolysis of triglycerides by breaking them down into their most elementary components (glycerol and fatty acids).
- RIBONUCLEASE and DEOXYRIBONUCLEASE: break down ribonucleic (RNA) and deoxyribonucleic (DNA) acids, respectively.
In addition to these digestive enzymes, pancreatic juice is rich in bicarbonate ions essential to buffer the acidity of the chyme coming from the stomach and ensure a slightly alkaline environment favorable to the activity of the digestive enzymes themselves.
Endocrine pancreas
The endocrine secretion of the pancreas is carried out by the islets of Langerhans, which play a leading role in controlling the metabolism of sugars, fats and proteins.
The endocrine portion of the pancreas produces two hormones that are very important to regulate the level of glucose in the blood:
- insulin: it is produced by beta cells which quantitatively represent about 3/4 of the islets of the Langehrans;
- glucagon: produced by alpha cells (20% of the total mass of the Langehrans islets).
A third, called somatostatin, and a fourth, the pancreatic polypepetis, are associated with these pancreatic hormones.
As mentioned in the introductory part, the hormones produced by the endocrine portion of the pancreas are released directly into the blood capillaries surrounding the islets.
To learn more about the individual functions of these hormones, click on the link of your interest:
- insulin,
- glucagon,
- somatostatin,
- carbohydrate metabolism.
Diseases of the Pancreas
Among the diseases that can affect the pancreas or that depend on its malfunction, we remember:
Diabetes Type 1 diabetes Cystic fibrosis Insulinoma Pancreatitis Malabsorption syndrome Zollinger-Ellison syndrome Pancreatic cancer
