Correctly Label the Following Glands of the Endocrine System

The answer

Working top to bottom through the body, label the endocrine glands in this order:

1. Pituitary gland — hangs beneath the hypothalamus in the brain (in the sella turcica).
2. Pineal gland — deep in the brain, posterior to the third ventricle.
3. Thyroid gland — front of the neck, wrapping around the trachea below the larynx.
4. Parathyroid glands — four small glands on the posterior thyroid.
5. Thymus — in the upper chest behind the sternum (large in children, shrinks in adults).
6. Adrenal (suprarenal) glands — one sitting atop each kidney.
7. Pancreas — behind the stomach; its islets of Langerhans are the endocrine portion.
8. Gonads — ovaries in females (pelvis) or testes in males (scrotum).

The hypothalamus is often included as the master controller that directs the pituitary.

Which gland does what

The content gap competitors leave open is linking each gland to its hormones:

• Pituitary — the "master gland": secretes growth hormone, TSH, ACTH, FSH, LH, and prolactin (anterior), and releases ADH and oxytocin (posterior).
• Pineal — melatonin, regulating sleep-wake cycles.
• Thyroid — thyroxine (T4) and triiodothyronine (T3) for metabolism, plus calcitonin to lower blood calcium.
• Parathyroids — parathyroid hormone (PTH) to raise blood calcium.
• Thymus — thymosin, maturing T-lymphocytes for immunity.
• Adrenals — cortex makes cortisol and aldosterone; medulla makes adrenaline (epinephrine) and noradrenaline.
• Pancreas — insulin (lowers blood glucose) and glucagon (raises it).
• Ovaries — estrogen and progesterone; testes — testosterone.

Why the pituitary is the "master gland"

The pituitary earns its title because its hormones control other endocrine glands: TSH drives the thyroid, ACTH drives the adrenal cortex, and FSH/LH drive the gonads. But the pituitary itself takes orders from the hypothalamus, so many texts now call the hypothalamus the true master regulator.

Common labeling errors

Students often swap the thyroid and thymus because the names sound alike — remember the thyroid is in the neck and the thymus is in the chest. Another frequent mistake is confusing the adrenal glands with the kidneys; the adrenals are the small caps on top of each kidney, and the kidney itself is a urinary organ (though it does release some hormones). Finally, the pancreas is a mixed gland: most of it is exocrine (digestive enzymes), but the islets of Langerhans provide its endocrine function.