Pancreas: Endocrine and Exocrine Glands, Hormones, Functions & Releasing Sites
The pancreas is a vital glandular organ of the digestive and endocrine systems. It is located in the upper abdomen, behind the stomach, and plays a dual role in maintaining blood glucose regulation and proper digestion. This article explains the structure of the pancreas, its endocrine and exocrine components, their hormones and enzymes, releasing sites, functions, disorders, and care.
Introduction to Pancreas
The pancreas is a soft, elongated organ measuring approximately 12–15 cm, shaped like a leaf or fish. It lies in the retroperitoneal space and is divided into four main parts:
• Head
• Neck
• Body
• Tail
It connects to the duodenum through the pancreatic duct and receives rich blood supply from branches of the splenic and pancreaticoduodenal arteries.
Dual Functions of the Pancreas
Role Type Output Purpose
Hormone secretion Endocrine Hormones into blood Blood glucose regulation & metabolism
Digestive enzyme secretion Exocrine Enzymes into duodenum Digestion of food (carbs, proteins & fats
Thus, the pancreas maintains both metabolism and nutrient absorption.
Endocrine Pancreas
The endocrine part consists of specialized clusters of cells known as Islets of Langerhans. They make up only 1–2% of total pancreatic mass but perform powerful metabolic functions.
Types of Islet Cells and Hormones
Cell Type Percentage Hormone Secreted Major Function
β-cells (Beta) 65–80% Insulin Lowers blood glucose
α-cells (Alpha) 15–20% Glucagon Raises blood glucose
δ-cells (Delta) 3–10% Somatostatin Inhibits insulin, glucagon & GI hormones
PP cells (F cells) 1% Pancreatic Polypeptide Controls pancreatic exocrine secretions
ε-cells (Epsilon) <1% Ghrelin Stimulates hunger
Major Endocrine Hormones & Their Functions
1. Insulin
• Releasing Site: Beta cells
• Target Organs: Liver, muscles, fat tissues
Main Actions:
• Promotes glucose uptake into cells
• Stimulates glycogenesis (glucose → glycogen in liver)
• Decreases breakdown of fats and proteins
Clinical Significance:
• Deficiency → Diabetes Mellitus Type 1
• Resistance → Type 2 Diabetes Mellitus
2. Glucagon
• Releasing Site: Alpha cells
• Target Organs: Liver, adipose tissues
Functions:
• Increases blood sugar by glycogenolysis
• Promotes gluconeogenesis
• Mobilizes stored fat
3. Somatostatin
Releasing Site: Delta cells
Functions:
• Universal inhibitory hormone
• Suppresses :
• Insulin & glucagon secretion
• Growth hormone release
• Gastrointestinal motility
4. Pancreatic Polypeptide
• Releasing Site: PP cells
Functions:
• Inhibits pancreatic exocrine secretions
• Regulates hepatic glycogen levels
5. Ghrelin
Releasing Site: Epsilon cells
Function:
• Triggers hunger signals
• Promotes feeding behavior
Together, endocrine hormones maintain carbohydrate metabolism, energy balance, and homeostasis.
Exocrine Pancreas
The exocrine portion consists of acinar cells which produce digestive enzymes that help break down food in the duodenum.
It makes up 98% of pancreatic tissue.
Secretions of Exocrine Pancreas
Secretion Category Major Components Action
Digestive Enzymes Amylase, Lipase, Proteases (Trypsin, Chymotrypsin) Break down food
Bicarbonate Ions (HCO₃⁻) Neutralize acidic chyme Protect intestinal lining & regulate pH
Major Digestive Enzymes
1. Amylase
• Site Released: Pancreatic duct → Duodenum
• Function: Carbohydrate digestion (starch → maltose)
↑ Levels used in diagnosis of pancreatitis
2. Lipase
• Action: Converts fats → fatty acids + glycerol
• Essential for fat absorption
Proteolytic Enzymes
Enzyme Secreted Form Activation Site Function
Trypsin Trypsinogen In the duodenum Breaks proteins
Chymotrypsin Chymotrypsinogen Duodenum Digests proteins
Carboxypeptidase Procarboxypeptidase Duodenum Breaks peptides
To avoid self-digestion, enzymes are released as inactive precursors (zymogens).
• Bicarbonate Secretion
• Produced by ductal cells
• Neutralizes highly acidic chyme from the stomach
• Supports enzyme activity at optimal pH (alkaline)
Regulation of Pancreatic Secretions
Hormones controlling pancreatic enzyme release:
Hormone Source Action
Secretin Duodenum Stimulates bicarbonate secretion
CCK (Cholecystokinin) Small intestine Stimulates enzyme secretion & contraction of gallbladder
Gastrin Stomach Mild stimulation of exocrine pancreas
Nervous system also regulates secretion via vagus nerve (parasympathetic).
Pancreatic Disorders
The pancreas can be affected by a variety of conditions:
Disease Problem Major Symptoms
Diabetes mellitus Insulin deficiency/resistance Excess urination, thirst, weight loss
Acute pancreatitis Inflammation due to enzymes Severe abdominal pain, nausea
Chronic pancreatitis Long-term damage Steatorrhea, malnutrition
Pancreatic cancer Malignant tumor Painless jaundice, weight loss
Cystic fibrosis Thick mucus blocks ducts Poor digestion
Pancreatic insufficiency Lack of enzymes Fatty stools, weight loss
Diagnosis of Pancreatic Diseases
Test Purpose
Blood glucose & HbA1c Diabetes assessment
Serum amylase & lipase Pancreatitis confirmation
Ultrasound & CT scan Structural abnormalities
ERCP & MRCP Duct evaluation
Fecal elastase test Exocrine insufficiency
Early diagnosis reduces complications significantly.
Treatment & Management
Condition Treatment
Diabetes Insulin therapy, oral antidiabetics, diet
Pancreatitis Pain relief, fasting, IV fluids, enzyme therapy
Pancreatic cancer Surgery (Whipple procedure), chemo
Pancreatic insufficiency Pancreatic enzyme replacement therapy
Lifestyle changes are key factors in maintaining pancreatic health.
How to Keep the Pancreas Healthy?
Recommended Lifestyle Tips:
• Maintain balanced diet rich in fiber
• Avoid high-fat, fried, and processed foods
• Stop smoking and limit alcohol
• Exercise regularly
• Maintain healthy weight
• Control diabetes and triglyceride levels
• Stay hydrated
Foods Beneficial for Pancreas:
• Leafy greens, broccoli, tomatoes
• Probiotic foods (yogurt, kefir)
• Lean proteins
• Whole grains
• Antioxidant-rich fruits (blueberry, orange)
Difference Between Endocrine and Exocrine Pancreas
Feature Endocrine Pancreas Exocrine Pancreas
Cell Type Islets of Langerhans Acinar cells
Secretion Hormones Digestive enzymes
Release Site Bloodstream Duodenum via ducts
Function Blood glucose regulation Food digestion
Disorders Diabetes Pancreatitis, malabsorption
Conclusion
The pancreas is a remarkable organ responsible for both metabolic regulation and digestion. The endocrine part secretes essential hormones like insulin and glucagon to balance blood sugar, while the exocrine part produces enzymes that digest carbohydrates, proteins, and fats.
Maintaining pancreatic health is essential to prevent life-threatening conditions like diabetes and pancreatitis. A healthy lifestyle, early screening, and proper clinical care can protect this vital organ and ensure overall wellbeing.
What is the main function of the pancreas?
The pancreas helps control blood sugar through hormone production and assists digestion by producing digestive enzymes.
Which hormones are produced by the pancreas?
Insulin, glucagon, somatostatin, pancreatic polypeptide, and ghrelin.
What is pancreatic insufficiency?
A condition where the pancreas fails to release enough digestive enzymes, causing malabsorption and weight loss.
Why does pancreatitis occur?
Usually due to alcoholism, gallstones, infections, or high triglyceride levels.
How can I prevent pancreatic disease?
Eat healthy food, avoid smoking and alcohol, exercise daily, and manage diabetes and obesity.
I hope that you liked this article.
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Writer: Vandita Singh, Lucknow (GS India Nursing Group)