Hypothalamic Regulation of Hormones

The hypothalamus controls the internal environment's chemical constancy, temperature, emotional and instinctive behaviors.

The posterior pituitary is an extension of the hypothalamus, composed of axon terminals that release hormones directly into the blood.

The anterior pituitary arises from Rathke's pouch, connected to the hypothalamus via the hypophyseal portal system.

The network of blood vessels that carries regulatory hormones to the anterior pituitary.

Hormones released by the hypothalamus to control the release of other hormones in the anterior pituitary.

Hormones produced in the hypothalamus and released by the posterior pituitary.

A common name for the pituitary gland due to its control over other endocrine glands.

Hypothalamic nuclei that produce and send oxytocin and vasopressin axons to the posterior pituitary.

Increased thirst during or after meals, triggered by the rise in blood osmolality caused by food absorption.

Thirst triggered by a decrease in blood volume, even if blood osmolality is normal, due to the renin-angiotensin system.

A hormonal system activated in response to low blood volume, leading to increased angiotensin II, which stimulates thirst.

A hormone that stimulates thirst centers in the brain, primarily the subfornical organ (SFO) and organum vasculosum of the lamina terminalis (OVLT).

Brain regions outside the blood-brain barrier, sensitive to blood changes and directly involved in thirst regulation.

A hormone released by the posterior pituitary that regulates water balance by promoting kidney water reabsorption.

A hormone released by the posterior pituitary that triggers uterine contractions during childbirth and milk release during breastfeeding.

Releases vasopressin (for water balance) and oxytocin (for uterine contractions and milk release).

The hypothalamus controls the anterior pituitary's hormone release indirectly, using blood vessels called the hypophyseal portal system, instead of direct nerve connections.

These specialized blood vessels carry hypothalamic hormones to the anterior pituitary, allowing rapid and direct communication.

A network of tiny, permeable blood vessels at the base of the hypothalamus, where hypothalamic hormones enter the bloodstream.

The blood flow from the hypothalamus to the anterior pituitary is direct, without going to the heart first, allowing rapid hormone transfer.

The area at the base of the hypothalamus where the portal vessels begin, outside the blood-brain barrier, allowing efficient hormone release.

Occurs when the concentration of solutes in the blood (osmolality) increases, triggering thirst to dilute the blood and restore balance.

These sensors in the heart and blood vessels detect changes in blood pressure, triggering thirst when blood volume is low.

Besides osmolality and blood pressure, other factors like dry mouth and psychological cues can trigger thirst.

Synthesized in the hypothalamus, these hormones travel along axons to the posterior pituitary where they are stored and released into the bloodstream in response to electrical signals.

Also known as antidiuretic hormone (ADH), it increases water reabsorption in the kidneys by making the collecting ducts more permeable, resulting in concentrated urine and reduced volume.

Found in the Suprachiasmatic Nucleus (SCN), brainstem and spinal cord, and in other organs like the gonads, adrenal cortex, and thymus.

Plays a role in childbirth (uterine contractions) and lactation (milk release) and has been linked to social bonding and trust.

Hormones produced and released directly into circulation by nerve cells.

Three main types: V1A, V1B, and V2. They all are G-protein coupled receptors that activate different intracellular pathways.

These receptors trigger an increase in intracellular Ca2+ concentrations via phosphatidylinositol hydrolysis.

V2 receptors increase cyclic adenosine monophosphate (cAMP) levels through the Gs protein.

When vasopressin is absent, urine becomes dilute (hypotonic) and volume increases, leading to net water loss. This raises the body's osmolality.

Oxytocin primarily affects the breasts and uterus in humans, triggering milk release and uterine contractions during childbirth. It also plays a role in luteolysis.

The anterior pituitary secretes six main hormones: ACTH, TSH, growth hormone, FSH, LH, and prolactin. β-lipotropin is secreted with ACTH, but its function is unknown.

These are chemicals released by the hypothalamus that regulate anterior pituitary hormone secretion. They are sometimes called releasing or inhibiting factors.

The complex interplay between the hypothalamus and anterior pituitary, where hypothalamic hormones control anterior pituitary hormone release.

A hypothalamic hormone that stimulates the release of ACTH from the anterior pituitary, mainly controlling stress response.

A hypothalamic hormone that stimulates the release of TSH from the anterior pituitary, essential for thyroid hormone production.

A hypothalamic hormone that stimulates the release of growth hormone from the anterior pituitary, promoting growth and development.