Pituitary Gland

The pituitary gland is a small, pea-sized gland at the base of the brain that controls other glands by releasing hormones, earning it the nickname 'the master gland' in the endocrine system (AP Psych Unit 2).

Verified for the 2027 AP Psychology examLast updated June 2026

What is the Pituitary Gland?

The pituitary gland is a tiny structure, about the size of a pea, sitting at the base of your brain just below the hypothalamus. Despite its size, it runs the show for your whole hormone system, which is why it's nicknamed the master gland. It releases hormones that tell other glands when to release their hormones, so it's basically the manager handing out instructions to the rest of the endocrine team.

One of its best-known jobs is releasing growth hormone, which (as the name says) controls physical growth. The pituitary doesn't act alone though. It takes orders from the hypothalamus right above it, so the real chain of command is brain to hypothalamus to pituitary to the rest of your glands. This makes it a key link between your nervous system (electrical, fast) and your endocrine system (chemical, slower but longer-lasting).

Why the Pituitary Gland matters in AP Psychology

The pituitary gland lives in Topic 2.2: The Endocrine System inside Unit 2: Cognition. On the AP Psych exam, the endocrine system shows up under the biological perspective, the lens that explains behavior through physical structures and chemicals. Knowing the pituitary is the master gland tells you how your body coordinates slow, body-wide changes like growth, stress responses, and daily rhythms. It's the chemical messenger counterpart to the fast electrical signals of neurons, so it rounds out the picture of how biology drives behavior.

How the Pituitary Gland connects across the course

Hypothalamus (Unit 2)

The hypothalamus sits right above the pituitary and gives it orders, so think of the hypothalamus as the boss and the pituitary as the manager who actually distributes the work to other glands.

Anterior and Posterior Pituitary (Unit 2)

The pituitary isn't one blob. The anterior (front) part makes its own hormones like growth hormone, while the posterior (back) part stores and releases hormones made by the hypothalamus.

Fight or Flight Response (Unit 2)

When you're stressed, the pituitary signals the adrenal glands to pump out stress hormones. So the master gland is a key trigger in the chemical side of your body's threat response.

Biological Perspective (Units 0 & 2)

The endocrine system is part of explaining behavior through biology. The pituitary shows that not all behavior comes from neurons firing; hormones shape mood, growth, and stress too.

Is the Pituitary Gland on the AP Psychology exam?

Endocrine questions are usually multiple-choice on the AP Psych exam. Expect stems like 'What hormone does the pituitary gland release that stimulates growth?' (answer: growth hormone) or 'What is the primary function of the pituitary gland?' (answer: it controls other glands as the master gland). You may also see it tested by elimination, where a question asks which gland controls metabolism and body temperature (that's the thyroid, NOT the pituitary), so know what each gland actually does. To use this term well, be able to name the pituitary as the master gland, connect it to the hypothalamus above it, and identify growth hormone as one of its outputs.

The Pituitary Gland vs Hypothalamus

The hypothalamus is a brain region that controls the pituitary; the pituitary is a gland that controls the rest of the endocrine system. The hypothalamus gives the orders, the pituitary carries them out to other glands. Don't flip the chain of command.

Key things to remember about the Pituitary Gland

  • The pituitary gland is a pea-sized gland at the base of the brain, nicknamed the 'master gland' because it controls other glands.

  • It releases growth hormone, which regulates physical growth, a common exam answer.

  • The hypothalamus sits above the pituitary and directs it, so the chain runs hypothalamus to pituitary to other glands.

  • The pituitary has two parts: the anterior (front) makes hormones, and the posterior (back) stores and releases hypothalamus-made hormones.

  • It lives in Unit 2, Topic 2.2, and represents the chemical, hormone-based side of the biological perspective.

Frequently asked questions about the Pituitary Gland

What is the pituitary gland in AP Psychology?

It's a pea-sized gland at the base of your brain that controls the rest of your endocrine system by releasing hormones. That control role is why it's called the master gland, and it's covered in Unit 2, Topic 2.2.

Is the pituitary gland really the 'master gland'?

Yes, but with a catch. It controls other glands, so the master nickname fits, but it takes its own orders from the hypothalamus above it. So it's more like a master manager than the ultimate boss.

How is the pituitary gland different from the hypothalamus?

The hypothalamus is a brain region that signals the pituitary; the pituitary is a gland that signals the rest of the endocrine system. The hypothalamus is the boss, the pituitary is the manager passing instructions down.

What hormone does the pituitary gland release?

The most commonly tested one is growth hormone, which regulates physical growth. The anterior pituitary makes hormones like this, while the posterior pituitary stores and releases hormones made by the hypothalamus.

Does the pituitary gland control metabolism?

Not directly. The thyroid gland controls metabolism and body temperature. The pituitary's job is to signal glands like the thyroid, so it manages metabolism indirectly through the hormones it releases.