What is Pancreas?
What is Pancreas?The pancreas is a complex organ made up of both exocrine and endocrine regions, with the endocrine part being made up of discrete islets of Langerhans that secrete several hormones.
- The involvement of cells in diabetes has increased over the years in studies of Langerhans Island.
- Islets, which consist of several thousand endocrine cells, make up about 2% of the total pancreatic mass.
- The main function of the endocrine region of the pancreas is to aid digestion by releasing hormones that help metabolize various biomolecules.
- The pancreas is a soft, tadpole-shaped organ that sits behind the abdomen. It has been postulated that the pancreas developed as a protuberance of the epithelial lining of the gastrointestinal tract.
- Insulin and glucagon are two important hormones secreted by the cells of the islet of Langerhans. However, the endocrine region secretes at least three other hormones.
- The endocrine zone of the pancreas begins to form around ten weeks of gestation through the proliferation and differentiation of an immature epithelial duct.
- The cellular composition and size of the cells on Langerhans Island depend mainly on the species.
Structure of Pancreas
- The proportion of islets of Langerhans in the pancreas is usually around 2%, with the total number of islets in humans ranging from 3.2 to 14.8 million.
- The cellular composition of islets varies in different species, and islets of different species have also been studied to have functional differences.
- The islets of Langerhans in humans contain four different cell types; α-cells, β-cells, cells and / or PP (pancreatic polypeptide-producing) cells.
- These four different cell types of the islets are randomly arranged by the gland.
- The size of the islets in the pancreas suggests variation as most of the islets follow the mantle-core pattern.
- Pancreatic β cells make up about 60% of the total islet mass, followed by α cells which make up 30% of the mass. The remaining 10% are covered by PP cells.
- The blood and nerve supply to the gland is facilitated by a neuromuscular bundle that penetrates the central nucleus of the β-cells.
- Four different cells on the islets secrete four different hormones that affect the body’s metabolism.
Hormones of Pancreas
There are four different types of cells in the pancreas that secrete four different hormones (insulin, glucagon, somatostatin, and pancreatic polypeptide).
Insulin is secreted by the β cells of the islets of Langerhans as a polypeptide made up of around 50 amino acids.
The main function of insulin is to lower the levels of nutrients in the blood, mainly glucose, but it can also contain amino acids and fatty acids.
The action of insulin is called anabolic because it makes it easier for the body to store nutrients.
Insulin is synthesized as part of a larger polypeptide unit called proinsulin, which is then clipped to release insulin.
Insulin works through one of three mechanisms; It improves the transport of glucose to various cells in the body and also prevents the breakdown of glycogen in glucose. It also prevents amino acids or fats from being converted into glucose.
Glucagon is secreted by the α-cells of the pancreas, which works on a mechanism opposite to that of insulin.
Glucagon is a polypeptide made up of 29 amino acids linked together to form a long polypeptide.
Glucagon is an extremely powerful hyperglycemic agent that causes glucose to be released into the blood.
The target organ for the glucagon hormone is the liver, where it promotes the breakdown of glycogen in glucose so that it raises blood sugar levels.
The hormone also activates the synthesis of glucose from lactic acid and non-carbohydrate molecules.
A decrease in the level of amino acids in the blood has a secondary effect as a result of an increase in blood sugar levels.
The release of glucagon by α-cells is induced by the stimulation of the sympathetic nervous system as well as by a drop in blood sugar level due to increased amino acid levels.
What are the function of the pancreas?
Below are some of the functions of the pancreas;
- The endocrine part of the gland releases various hormones that help maintain blood nutrient levels in the body.
- Insulin, secreted by the α-cells in the islets of Langerhans, is responsible for lowering blood sugar levels in humans.
- The pancreas also secretes glucagon, which increases blood sugar levels when levels go below normal.
- Cells in the islets of Langerhans release the hormone somatostatin, which inhibits the secretion of insulin and glucagon and at the same time inhibits the secretion of growth hormone by the pituitary gland.
Diseases and disorders of the pancreas
The following is one of the disorders and diseases associated with the pancreas;
- Diabetes mellitus is a disease that results from hyposecretion or hypoactivity of insulin.
- There are two types of diabetes mellitus; Type 1 diabetes mellitus results from the hyposecretion of insulin, while type 2 diabetes mellitus results from the hypoactivity of the released insulin.
- Due to the lack of insulin in the body, blood sugar levels rise, causing additional loss of glucose through the urine.
- Type 1 diabetes mellitus is common in children and is characterized by symptoms appearing immediately.
- Type 2 diabetes, on the other hand, is more common in adults and often results in the onset of symptoms late.
- Diabetes mellitus can be life-threatening in some situations, leading to kidney failure and other serious illnesses. In most cases, however, the condition is chronic and does not result in death.
- Diabetes mellitus is treated with insulin injections, which help maintain insulin levels in the body.
What is Pancreas? Structure, What are the function of the pancreas?