Antidiuretic Hormone (ADH) Lecture Notes

Vocabulary flashcards covering key terms related to the synthesis, regulation, actions, and disorders of antidiuretic hormone (ADH).

Antidiuretic Hormone (ADH)

A peptide hormone that prevents excessive urine formation by promoting water reabsorption in the kidneys.

Vasopressin

Another name for ADH, highlighting its ability to constrict blood vessels and raise blood pressure.

Anti-diuresis

The process of reducing urine output to conserve body water, mediated chiefly by ADH.

Vasoconstriction

Narrowing of blood vessels’ smooth muscle, increasing blood pressure; one of ADH’s target actions.

High Blood Osmolarity

Elevated solute concentration in blood (dehydration) that triggers ADH release.

Osmoreceptor

Hypothalamic sensor that detects blood osmolarity changes and signals ADH secretion.

Stretch Receptor

Sensor in the vena cava and right atrium that monitors blood volume; low stretch stimulates ADH release.

Baroreceptor

Pressure receptor in the aortic arch and carotid arteries; low arterial pressure activates ADH secretion.

Hypothalamus (ADH Production)

Brain region where ADH is synthesized in neurosecretory cells before transport to the posterior pituitary.

Posterior Pituitary

Gland that stores and releases ADH into the bloodstream.

Collecting Duct

Nephron segment where ADH increases water permeability, concentrating urine.

Smooth Muscle in Arteries

Peripheral vessel tissue that constricts under ADH influence, elevating blood pressure.

Water Reabsorption

Movement of water from kidney filtrate back into blood, increased by ADH.

Peptide Hormone

Hormone class made of amino-acid chains; ADH consists of nine amino acids.

Angiotensin II

Hormone that stimulates ADH release as part of the body’s response to low blood pressure.

Diabetes Insipidus

Disorder caused by ADH hyposecretion or renal insensitivity, leading to excessive dilute urine and intense thirst.

Hyposecretion of ADH

Inadequate ADH production/release that results in diabetes insipidus symptoms.

Alcohol & ADH

Alcohol inhibits ADH secretion, causing increased urine output.

Dehydration

State of body water deficit signaled by high blood solute levels, a major trigger for ADH release.

Stimulus for ADH Release

Any condition such as high blood solute concentration, low volume, or low pressure that initiates ADH secretion.