Q.Fill in the blanks (any five): ADH is secreted by _____.

Hypothalamus Hormones: The Brain's Command Centre for Your Hormones

Think of your body as a giant company. The hypothalamus is the CEO — it sits in the brain, constantly monitoring what's happening inside you. It checks your temperature, your hunger, your stress levels, your sleep cycle. When something needs adjusting, the CEO doesn't do the work itself. Instead, it sends a memo to the pituitary gland — the middle manager — who then sends instructions down to the actual workers (thyroid, adrenal glands, ovaries, testes, etc.).

Those memos from the hypothalamus are what we call releasing hormones and inhibiting hormones.

The Intuition: A "Go" or "Stop" Signal

The hypothalamus produces tiny protein-like molecules that travel a very short distance — just down a thin stalk called the infundibulum — straight into the anterior pituitary. Once there, each hormone either says:

• "Go ahead, release your hormone!" — this is a releasing hormone.
• "Stop, don't release anything right now." — this is an inhibiting hormone.

That's it. The hypothalamus doesn't control the body directly. It controls the pituitary, which then controls everything else. This is called the hypothalamic-pituitary axis.

The Precise Statement

The hypothalamus secretes neurohormones into the hypophyseal portal system — a special network of blood vessels that runs directly from the hypothalamus to the anterior pituitary. These neurohormones are of two types:

1. Releasing hormones — stimulate the anterior pituitary to secrete its own hormones.
2. Inhibiting hormones — suppress the secretion of anterior pituitary hormones.

The Key Players You Must Know

Here are the major hypothalamic hormones and what they do:

Why This Matters for Exams

You will often be asked to trace a pathway. For example:

"Explain how cold temperature leads to increased thyroid hormone secretion."

The answer is not "the thyroid works harder." The correct chain is:

1. Cold detected by hypothalamus. …