Integration of Salt and Water Balance

These flashcards cover key terms and definitions related to the integration of salt and water balance in the body, focusing on ECF volume, osmolality, associated hormones, and regulatory mechanisms.

ECF volume

Extracellular fluid (ECF) volume refers to the amount of fluid outside the cells in the body.

ECF osmolality

ECF osmolality is a measure of the solute concentration in extracellular fluid.

Homeostatic mechanisms

Regulatory processes that maintain stability in the body's internal environment.

Na⁺ and Cl⁻

Principal ions in the extracellular fluid that influence its volume and osmolality.

Renin-angiotensin-aldosterone system (RAAS)

A hormone system that regulates blood pressure and fluid balance through renin secretion.

Baroreceptors

Sensors that detect changes in blood pressure; can be high-pressure or low-pressure.

ANT

Atrial natriuretic peptide, a hormone that reduces Na⁺ excretion when blood volume decreases.

Angiotensin I

The inactive precursor to angiotensin II formed by the action of renin on angiotensinogen.

Angiotensin II

A physiologically active hormone that stimulates aldosterone release and constricts blood vessels.

Arginine vasopressin (AVP)

A hormone that regulates water balance and increases water reabsorption in the kidneys.

Osmoreceptors

Neurons that detect changes in plasma osmolality and regulate the release of AVP.

Antidiuresis

The process through which the kidneys conserve water, reducing urine output.

Non-osmotic control of AVP secretion

Factors other than osmolality that influence the secretion of AVP, such as blood volume.

Effective circulating volume

The volume of blood effectively perfusing tissues, closely related to ECF volume.

Sodium appetite

The drive to consume sodium, often triggered by increased osmolality.