Pancreas: Structure, Functions & Hormones Part-12

Introduction

The pancreas is an important glandular organ of the digestive and endocrine systems. It plays a dual role by producing digestive enzymes (exocrine function) and hormones that regulate blood glucose levels (endocrine function). Proper functioning of the pancreas is essential for digestion, metabolism, and maintaining glucose homeostasis.

Location

The pancreas is located in the upper abdominal cavity, behind the stomach.

It lies horizontally across the posterior abdominal wall.

Extends from the duodenum (right side) to the spleen (left side).

It is retroperitoneal in position.

Size and Shape

Length: approximately 12–15 cm

Weight: about 70–100 grams

Soft, elongated, and leaf-shaped organ

Parts of the Pancreas

The pancreas is divided into four main parts:

Head

Broadest part

Lies in the C-shaped curve of the duodenum

Contains the uncinate process

Neck

Short portion between head and body

Lies anterior to major blood vessels

Body

Long, central portion

Extends leftwards across the abdomen

Tail

Narrow, tapering end

Lies near the hilum of the spleen

Rich in endocrine tissue

Structure of the Pancreas

The pancreas is composed of exocrine and endocrine components.

Exocrine Pancreas

Makes up about 98% of the pancreatic tissue

Consists of acinar cells

Produces digestive enzymes:

Amylase – digests carbohydrates

Lipase – digests fats

Proteases (trypsin, chymotrypsin) – digest proteins

Enzymes are secreted into the pancreatic duct

Pancreatic duct joins the common bile duct and opens into the duodenum

Endocrine Pancreas (Islets of Langerhans)

Scattered clusters of hormone-producing cells

Directly release hormones into the bloodstream

Types of Cells and Hormones
Cell Type Hormone Function
Alpha (α) cells Glucagon Raises blood glucose
Beta (β) cells Insulin Lowers blood glucose
Delta (δ) cells Somatostatin Inhibits insulin & glucagon
PP cells Pancreatic polypeptide Regulates digestive activity
Blood Supply

Supplied by branches of the celiac trunk and superior mesenteric artery

Venous drainage into the portal vein

Functions of the Pancreas
1. Digestive Function

Secretes pancreatic juice containing enzymes

Aids digestion of carbohydrates, proteins, and fats

2. Hormonal Function

Regulates blood sugar levels

Maintains glucose balance (homeostasis)

Regulation of Pancreatic Secretion

Secretin stimulates bicarbonate secretion

Cholecystokinin (CCK) stimulates enzyme secretion

Nervous control via vagus nerve

Common Disorders of the Pancreas

Pancreatitis (acute and chronic)

Diabetes mellitus

Pancreatic cancer

Cystic fibrosis

Insulinoma

Clinical Importance

Damage to pancreas affects digestion and blood glucose control

Removal or dysfunction leads to malabsorption and diabetes

Pancreatic enzyme supplements may be required