Posterior Pituitary & Pancreatic Hormones

What are the two hormones of the posterior pituitary?

ADH (antidiuretic hormone) and Oxytocin.

Where are they made?

In hypothalamic nuclei:Paraventricular nucleus → Oxytocin

• Supraoptic nucleus → ADH

How do they reach the posterior pituitary?

Travel down axons of the hypothalamo-hypophyseal tract and are released into blood.

What does ADH do?

Increases kidney water reabsorption → raises blood volume and pressure.

What does oxytocin do?

Triggers uterine contractions and milk ejection (positive feedback loop).

What are the two main pancreatic hormones?

Insulin (from β-cells) and Glucagon (from α-cells).

What does insulin do?

Lowers blood glucose by promoting glycogen formation and glucose uptake.

What does glucagon do?

Raises blood glucose by breaking down glycogen in the liver

What triggers insulin release?

High blood glucose after meals

What triggers glucagon release?

Low blood glucose between meals.

How do these hormones interact?

They are antagonists maintaining glucose homeostasis.

What are the two main diabetes types?

• Type I (IDDM): No insulin production (autoimmune).

• Type II (NIDDM): Reduced insulin detection or production (often lifestyle-related).