Biology · Chemical Coordination and Integration · NEET
No. This is the whole point. The posterior pituitary (neurohypophysis) makes zero hormones of its own. Oxytocin and vasopressin (ADH) are synthesised in the hypothalamus. They travel down the axons (nerve fibres) into the posterior pituitary, where they are stored and later released into the blood. So it acts only as a storage and release site.
Because hormones ARE released into the blood from it. It is a release point for two real hormones, so functionally it is part of the endocrine system. But a 'true' endocrine gland must SYNTHESISE its own hormone. Since the posterior pituitary only stores what the hypothalamus made, NCERT calls it a store-and-release structure, not a true gland.
The anterior pituitary (adenohypophysis / pars distalis) is a TRUE endocrine gland — it makes its own six hormones: GH, PRL, TSH, ACTH, LH and FSH. The posterior pituitary (neurohypophysis / pars nervosa) makes none; it only stores and releases oxytocin and vasopressin made by the hypothalamus. Anterior = maker, posterior = storekeeper.
They travel by axonal transport. The hypothalamic neurons that make oxytocin and vasopressin have long axons that run down the stalk into the posterior pituitary. The hormones move along these nerve fibres (not through blood) and are stored at the nerve endings. NCERT states they are 'transported axonally to neurohypophysis'.
No — this is a common mix-up. The hypothalamus controls the ANTERIOR pituitary through a blood link called the hypophyseal portal system, using releasing and inhibiting hormones. It controls the POSTERIOR pituitary through a nerve (axonal) link. Blood route for anterior, nerve route for posterior.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
It is called the neurohypophysis or pars nervosa. 'Neuro' points to its nerve (axonal) connection with the hypothalamus.
Oxytocin and vasopressin (also called antidiuretic hormone, ADH). Both are made by the hypothalamus and only stored and released here.
The anterior pituitary (adenohypophysis / pars distalis) is the true endocrine gland because it synthesises its own hormones: GH, PRL, TSH, ACTH, LH and FSH.
Vasopressin acts on the kidney and increases resorption of water by the distal tubules, reducing water loss in urine (diuresis). Because it works against diuresis, it is called anti-diuretic hormone (ADH).
No. The pineal gland is a true endocrine gland — it synthesises its own hormone, melatonin. Only the posterior pituitary is the store-and-release exception among the pituitary parts.
