Topics:
Animal Physiology, Animal Refresher
Largest and Smallest Endocrine Glands
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Question (English)
Largest & smallest endocrine glands of the animal body are respectively:
- Thyroid & Pituitary
- Liver & Pituitary
- Thyroid & Pineal ✓ Correct
- Liver & Pineal
Explanation:
Correct Answer: Thyroid & Pineal
The largest endocrine gland is the thyroid and the smallest endocrine gland is the pineal gland.
Key Facts About Endocrine Glands
- Largest endocrine gland: Thyroid gland — butterfly-shaped, located in the neck ventral to the trachea. Secretes T3, T4 (regulate BMR) and calcitonin (lowers blood calcium).
- Smallest endocrine gland: Pineal gland — pea-sized, located in the brain (epithalamus). Secretes melatonin (regulates circadian rhythm and seasonal breeding). Peak melatonin secretion occurs at midnight.
- Largest endocrine organ (overall): GIT (gastrointestinal tract) — contains numerous hormone-secreting cells (G cells, S cells, I cells, etc.) scattered throughout its wall.
- Largest gland of the body (overall): Liver (exocrine + endocrine functions).
- Largest organ of the body: Skin.
Additional Notes on Pituitary
- The pituitary gland is the 'master gland' that controls most other endocrine glands, but it is NOT the largest endocrine gland — that title belongs to the thyroid.
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.