Which of the following is both an endocrine and exocrine gland?

ISRO- 2016

Applied Anatomy

Easy

Appeared in: ISRO- 2016

Explanation

The pancreas is classified as a heterocrine or mixed gland because it possesses both endocrine and exocrine functions.
Its exocrine function involves acinar cells that secrete digestive enzymes (like amylase and lipase) into the pancreatic duct, which carries them to the small intestine.
Its endocrine function is carried out by the Islets of Langerhans, which are clusters of cells that secrete hormones like insulin and glucagon directly into the bloodstream to regulate blood sugar levels.
The provided image visually confirms this dual structure, showing both the pancreatic duct (exocrine) and the Islets of Langerhans (endocrine).

Option A: The thyroid gland is a purely endocrine gland. It secretes hormones (T3, T4, calcitonin) directly into the bloodstream and does not have any ducts for exocrine secretions.
Option B: The pituitary gland is known as the 'master' endocrine gland. It is entirely endocrine, releasing hormones that control other glands, but it lacks an exocrine component.
Option D: The adrenal gland is a purely endocrine gland. It consists of the cortex and medulla, both of which produce and secrete hormones (like cortisol, aldosterone, and adrenaline) into the blood.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identification of mixed (heterocrine) glands, which have both endocrine and exocrine functions as background academic context rather than a clinical decision trigger.
Understanding the dual function of the pancreas is crucial for diagnosing and managing related diseases. Endocrine dysfunction leads to diabetes mellitus due to impaired insulin production.
Exocrine dysfunction, often seen in conditions like pancreatitis or cystic fibrosis, leads to maldigestion and malabsorption because digestive enzymes cannot reach the small intestine.
What if? If a patient develops a tumor in the head of the pancreas that blocks the pancreatic duct, the primary manifestation would be exocrine dysfunction (maldigestion, steatorrhea) and obstructive jaundice, even if the endocrine cells are initially unaffected.

How to Approach the Question

First, understand the definitions of the keywords in the question: 'endocrine gland' (ductless, secretes hormones into blood) and 'exocrine gland' (has ducts, secretes enzymes/substances to a surface).
The question asks for a gland that is 'both'. This means you are looking for a mixed or heterocrine gland.
Evaluate each option based on these definitions.
Recall or deduce the function of the Thyroid gland (endocrine).
Recall or deduce the function of the Pituitary gland (endocrine).
Recall or deduce the function of the Pancreas. Remember its role in producing both insulin (hormone) and digestive juices (enzymes). This makes it both endocrine and exocrine.

Concept Tested & Keywords

Concept Tested: Identification of mixed (heterocrine) glands, which have both endocrine and exocrine functions.
Stem keywords: endocrine gland, exocrine gland
Lead-in keywords: Which of the following

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