How are pituitary secretions controlled by negative feedback?

A. Antidiuretic hormone (ADH):ADH (vasopressin) promotes water reabsorption in the kidneys; deficiency reduces water reabsorption, producing excessive urine output (polyuria) and compensatory thirst (polydipsia), and head trauma can damage the hypothalamic–posterior pituitary axis causing this deficiency.
B. Aldosterone:Aldosterone increases sodium reabsorption and water retention in the distal nephron; deficiency can cause salt wasting and volume depletion but is less directly associated with the classic polyuria/polydipsia pattern seen after head trauma.
C. Oxytocin:Oxytocin primarily affects uterine contraction and milk ejection; deficiency does not typically produce polyuria and polydipsia.
D. Cortisol:Cortisol influences metabolism and stress responses and, in excess, can cause polyuria via osmotic diuresis from hyperglycemia, but isolated cortisol deficiency or excess is a less direct explanation for sudden polyuria and polydipsia following head trauma compared with ADH loss.

A. The hypothalamus is posterior to the pituitary gland:The hypothalamus is actually superior (above) and connected to the pituitary; it is not located posterior to the pituitary.
B. The hypothalamus is located within the sella turcica:The sella turcica is the bony depression in the sphenoid bone that houses the pituitary gland, not the hypothalamus, which lies superior to it in the diencephalon.
C. The pituitary gland is superior to the hypothalamus:The pituitary lies inferior to the hypothalamus; it is not superior.
D. The pituitary gland is connected to the hypothalamus by the infundibulum:The infundibulum (pituitary stalk) physically connects the hypothalamus to the pituitary, allowing neural and vascular communication between them.