Islets of Langerhans

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Introduction

Irregularly shaped patches of endocrine tissue which are located within the pancreas of many vertebrates are called Islets of Langerhans. They were first described in 1869 and named after the famous German physician named Paul Langerhans. One million Islets of Langerhans are present in one human pancreas. Important hormones are secreted from alpha, beta, and delta cells. Alpha, beta, delta are three distinct cell types present in the Islets of Langerhans. The fourth cell present here is the C cell which has no special function in our body. For the proper endocrine function of the pancreas, the islets of Langerhans are important.


The Function of Distinct Cells

The major hormone for the regulation of carbohydrate, fat, and protein metabolism is insulin. This insulin is secreted from the b cell.in several metabolic processes, insulin is crucial. It promotes the intake and metabolic rate of glucose by the body's cells. The secretion of glucose by the liver is also prevented by it. It helps the muscles to absorb amino acids and proteins as well. The breakdown and release of fat are also promoted by it. The release of insulin from the beta cell is promoted by growth hormone. Insulin helps to counter an increased level of glucose in the blood immediately after food is given to a body.


Islets of Langerhans Function

The main cell in the endocrine tissue is the islets of Langerhans in the pancreas. These cells in the pancreas remain clotted and produce a lot of hormones. The three cells that work better in the pancreas are alpha cells, beta cells, and delta cells. Alpha cells produce glucagon or glucose and their work is to increase blood sugar level. The beta-cell secrete insulin that opposes the increased blood sugar level. The delts cell produces somatostatin hormone. The fourth cell is also present but it has no specific function. In today’s world, a conversation on the usage of beta cells is ongoing. Doctors have decided to replenish the insulin secreted by the beta cell to treat diabetes.


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Islets of Langerhans Secrete

Islet of Langerhan secretes many hormones and maintains our body properly. There are four types of cells present in it. They are as follows:

  • Alpha cell

  • Beta-cell

  • Delta cell

  • C-cell.

Alpha Cells

Alpha cells of the pancreas secrete an opposing hormone. They are glucagon and glucose. Glucagon helps to release glucose from the liver. Glucagon also helps to secret fatty acids from fat tissues. In turn, the insulin released is favoured by free fatty acids and glucose. This inhibits the release of glucagon more. They cover 20% of the humans’ islets Langerhans. 


Beta Cells

Beta cells of the pancreas secrete the most important hormones amongst all. This insulin is secreted from the b cell.in several metabolic processes, insulin is crucial. It promotes the intake and metabolic rate of glucose by the body's cells. The secretion of glucose by the liver is also prevented by it. It helps the muscles to absorb amino acids and proteins as well. The breakdown and release of fat are also promoted by it. The release of insulin from the beta cell is promoted by growth hormone.  


Delta Cells

Delta cells of the pancreas secrete a strong inhibitor of somatotropin, glucagon, and insulin. The strong inhibitor is somatostatin. It has a role in metabolic regulation but its function is not clear. Hypothalamus also produces somatostatin. Its function there is to inhibit growth hormone with the help of the pituitary gland. These delta cells are also found in the stomach cells, intestine, and pancreatic islets of Langerhans. 


Solved Answers

1. Importance of Islet of Langerhans?

Ans: Pancreas is an important part of our body. It performs various functions in our body. Glucagon helps to release glucose from the liver. Glucagon also helps to secret fatty acids from fat tissues. In turn, the insulin released is favoured by free fatty acids and glucose. The secretion of glucose by the liver is also prevented by it. It helps the muscles to absorb amino acids and proteins as well.

2. What is the Reason For Diabetes Mellitus?

Ans: When the islet cells are unable to make insulin or unable to control blood glucose level, then a serious deformation occurs in the level of hormones in the body. This causes diabetes mellitus. 

3. What is the Number of Islets of Langerhans in the Human Pancreas?

Ans:   The human pancreas consists of one million islets of Langerhans.

FAQ (Frequently Asked Questions)

1. What is the Island of Langerhans?

Ans: The islets of Langerhgans are also known as islands of Langerhans. They have irregularly shaped patches or spots present in the walls of endocrine tissue. They are located inside the pancreas of almost every vertebrate. The strong inhibitor is somatostatin. It has a role in metabolic regulation but its function is not clear. Hypothalamus also produces somatostatin. Its function there is to inhibit growth hormone with the help of the pituitary gland. These delta cells are also found in the stomach cells, intestine, and pancreatic islets of Langerhans. The release of insulin from the beta cell is promoted by growth hormone. 

2. Describe the Endocrine Role of Islets of Langerhans?

Ans: The endocrine cell of the pancreas is known as the islet of Langerhans. There are four types of cell that secrete hormones.

Alpha cells: It covers 20% of the Islets of Langerhans. A hormone secreted is glucagon. Glycogenolysis is stimulated by glucagon. In the liver it(the breakdown of glycogen) causes hyperglycemia.

Beta cells:  It covers 70% of the Islets of Langerhans. Glycogenesis is stimulated by insulin that is produced by these cells. It spreads into livers and muscles. By increasing the uptake of glucose in cells it causes hypoglycemia.

Delta cells:  It covers 10% of the Islets of Langerhans. It inhibits the secretion of glucagon and insulin by secreting somatostatin. The absorption of motility, digestive juices in the stomach, and gastric secretion are lowered by it. The release of growth hormone is inhibited by somatostatin.

PP cells or F cell: Pancreatic polypeptide is secreted by this cell. It also inhibits the pancreatic juices that are released.