Cue Column | Notes Column

Hypothalamic nuclei for ADH | Supraoptic nucleus → synthesises ADH (vasopressin). Axons project to posterior pituitary nerve terminals.

Hypothalamic nuclei for oxytocin | Paraventricular nucleus → synthesises oxytocin. Same axonal transport to posterior pituitary.

Hypophyseal portal system | Carries hypothalamic releasing/inhibiting hormones from the median eminence to the anterior pituitary. NOT to the posterior pituitary.

Anterior pituitary cell types | Somatotrophs (GH), Thyrotrophs (TSH), Corticotrophs (ACTH), Gonadotrophs (FSH, LH), Lactotrophs (prolactin).

Why is prolactin unique? | Only anterior pituitary hormone primarily under INHIBITORY control. PIF (dopamine) tonically suppresses it. Removing dopamine → prolactin rises. All other AP hormones need a positive releasing signal.

Hormones of posterior pituitary | ADH: water reabsorption $\frac{kidney DCT}{collecting duct via aquaporins}$, vasoconstriction at high doses. Oxytocin: uterine contractions (labour), milk ejection reflex.

Long-loop negative feedback | Cortisol → inhibits CRH (hypothalamus) AND ACTH (pituitary). T3/T4 → inhibits TRH (hypothalamus) AND TSH (pituitary). Target hormone suppresses both levels.

Summary:

The anterior pituitary is under positive control by hypothalamic releasing hormones (via portal system); the posterior pituitary is an extension of hypothalamic neurons (no synthesis). Prolactin is unique (dopamine-inhibited). Negative feedback operates at two levels (hypothalamus and pituitary).