Pancreas

The human body has an enormous network of organs, each allotted to specific functions for the proper functioning of a body. These organs are collectively named as specific systems according to their concerned function. The major ones are as follows-

• Cardiovascular System
• Respiratory System
• Nervous System
• Digestive System
• Endocrine System
• Urinary System
• Reproductive System
• Musculoskeletal System
• Immune System

Here, the endocrine system consists of those organs which are responsible for secreting hormones into the bloodstream of the human body with the help of specific glands. Moreover, the organ ‘Pancreas’ happens to be a major part of this endocrine system. 

The Pancreas And Its Location

The pancreas is a glandular organ located in the region of the abdomen. It produces enzyme-containing pancreatic juices that aid in digestion, and it also contains several hormones, like insulin. It is surrounded by the stomach, intestines, and other organs. It is basically present in the curve of the duodenum and stomach and is entirely retroperitoneal meaning; it is present behind the peritoneum. Its average length varies between 4.7 and 5.8 inches and its average thickness is about 0.8 inches. The arteries responsible for the blood supply of the pancreas are:

• gastroduodenal artery
• pancreaticoduodenal arteries
• splenic artery

Parts Of Pancreas

The main exterior parts of the pancreas are:

• Head: it is the right enlarged part in the pancreas in the duodenal curvature. From its lower portion, a hook-like process called uncinate process is present
• Neck: it is the constricted region between the head and body
• Body: it is an elongated, tapered, triangular section lying across the post abdominal wall
• Tail: it is the narrow end that lies between 2 layers of lieno-renal ligament 

The pancreas has mainly two functional regions integrated into a single structure – exocrine glands and endocrine glands

• Exocrine glands: this region helps in secreting compounds into a cavity
• Endocrine glands: this region helps in secreting hormones into the bloodstream

Exocrine Glands

99% of the pancreas is made of acini, and clusters of exocrine digestive cells connecting the ducts. These exocrine glands as mentioned above help in secreting compounds into a cavity. This is achieved by two ducts –

• Main pancreatic duct: Also called the Wirsung’s duct, it commences from the tail, passes through the body, and joins the bile duct to form the Ampulla of Vater. This helps in supplying pancreatic juice which aids in digestion
• Accessory pancreatic duct: Also called the duct of Santorini, it commences from the uncinate process, crosses the main pancreatic duct, and opens in the minor duodenal papilla

Endocrine Glands 

1% of the pancreas is made of a large number of cells called Islets of Langerhans, which perform the endocrine functioning of the pancreas. These endocrine glands contain four major types of cells – 

• Alpha cells: 

These constitute 20% of the islet cells in the pancreas. They secrete the glucagon hormone which aids in increasing blood sugar levels at the required rate. The functions of glucagon are as follows:

1. It acts on hepatocytes to convert glycogen to glucose through a process called glycogenolysis
2. It also converts amino acids to glucose through a process called gluconeogenesis

• Beta cells: 

These constitute around 80% of the islet cells in the pancreas. They secrete the insulin hormone which aids in decreasing blood sugar levels at a required rate. The functions of insulin are as follows:

1. It helps in increasing the speed of diffusion of glucose into the cells
2. It helps in  accelerating the conversion of glucose into glycogen
3. It helps in increasing the synthesis of proteins from amino acids
4. It helps in increasing the synthesis of fatty acids
5. It helps in decreasing the rate of glycogenolysis and gluconeogenesis

• Delta cells: 

These constitute less than 1% of the islet cells in the pancreas. They secrete the somatostatin hormone and its functions are as follows:

1. It inhibits the release of insulin
2. It slows the absorption of nutrients from the gastrointestinal tract

• F cells: 

These constitute less than 1% of the islet cells in the pancreas. These release pancreatic polypeptide which in turn inhibits the release of somatostatin.

Disorders Of The Pancreas

• Pancreatitis: this has 4 major variations – acute, chronic, and hereditary. This refers to an inflammation in the pancreas wherein due to accumulation of pancreatic juices in the pancreas, leads to its damage. It often leads to secondary diabetes. Its main causes include – mumps, gallstones, trauma, alcohol, steroids, and drugs. 
• Pancreatic cancer: this is cancer developed in the pancreas often linked to smoking or heavy drinking. Its treatment often involves surgery, chemotherapy, or radiation treatment
• Diabetes: this has 2 variations – Type 1 and Type 2. 

• Type-1 Diabetes: this is an autoimmune disease caused to a lack of production of insulin by beta cells
• Type-2 Diabetes: this is caused due to the inability of glucose production by the body’s muscle, fat, and liver cells, and pancreas being unable to release insulin.

• Exocrine Pancreatic Insufficiency: this is caused when enzymes are not produced in enough levels
• Zollinger-Ellison syndrome: this is caused when a tumor known called gastrinoma develops in the pancreas or duodenum

Conclusion:

Thus we see that the pancreas aid in both endocrine and digestive functions of the human body. The digestive function of the pancreas is to secrete pancreatic juices whereas the endocrine function is to secrete hormones like insulin and glucagon.