Question
List the hormones secreted by the anterior and posterior pituitary gland. Describe the target organs and functions of each hormone.
(NEET, CBSE Class 11 — Chemical Coordination and Integration)
Solution — Step by Step
The anterior pituitary (adenohypophysis) secretes six major hormones:
- GH (Growth Hormone / Somatotropin) — stimulates growth, especially of bones and muscles
- TSH (Thyroid Stimulating Hormone) — stimulates thyroid to produce T3/T4
- ACTH (Adrenocorticotropic Hormone) — stimulates adrenal cortex to produce cortisol
- FSH (Follicle Stimulating Hormone) — stimulates follicle development in ovaries, spermatogenesis in testes
- LH (Luteinizing Hormone) — triggers ovulation, stimulates testosterone production
- Prolactin (PRL) — stimulates milk production in mammary glands
The posterior pituitary (neurohypophysis) does not synthesise hormones — it stores and releases two hormones made by the hypothalamus:
- Oxytocin — stimulates uterine contractions during labour and milk ejection
- ADH/Vasopressin (Antidiuretic Hormone) — promotes water reabsorption in kidney collecting ducts, reducing urine volume
The intermediate lobe (pars intermedia) secretes MSH (Melanocyte Stimulating Hormone) — regulates skin pigmentation. This lobe is rudimentary in humans.
graph TD
A["Pituitary Gland"] --> B["Anterior (Adenohypophysis)"]
A --> C["Posterior (Neurohypophysis)"]
B --> D["GH → Growth"]
B --> E["TSH → Thyroid"]
B --> F["ACTH → Adrenal cortex"]
B --> G["FSH → Gonads"]
B --> H["LH → Gonads"]
B --> I["Prolactin → Mammary glands"]
C --> J["Oxytocin → Uterus, Mammary"]
C --> K["ADH → Kidneys"]Why This Works
The pituitary is called the “master gland” because its hormones control other endocrine glands (TSH controls thyroid, ACTH controls adrenal, FSH/LH control gonads). But the pituitary itself is controlled by the hypothalamus through releasing and inhibiting hormones — so the hypothalamus is actually the “master of the master.”
The anterior pituitary makes its own hormones. The posterior pituitary merely stores hormones synthesised in the hypothalamus (supraoptic and paraventricular nuclei). This distinction is a favourite NEET question.
Alternative Method — Functional Grouping
Group by target: Tropic hormones (act on other glands): TSH, ACTH, FSH, LH. Direct-acting hormones: GH (bones/muscles), Prolactin (mammary), Oxytocin (uterus), ADH (kidneys).
Mnemonic for anterior pituitary hormones: FLAT PG — FSH, LH, ACTH, TSH, Prolactin, GH. For posterior: OA — Oxytocin and ADH. NEET tests this list directly.
Common Mistake
Students say the posterior pituitary “secretes” oxytocin and ADH. Technically, it releases them — these hormones are synthesised in the hypothalamus and transported to the posterior pituitary via axons (hypothalamo-hypophyseal tract). NEET questions are specific about this distinction.