Skip to main content
Ch. 25 Fluid, Electrolyte, and Acid-Base Homeostasis
Amerman- Human Anatomy & Physiology 3e
Amerman3rd EditionHuman Anatomy & PhysiologyISBN: 9780138247201, 9780138247928, 9780138201814Non è quello che usi tu?Cambia libro di testo
Tutti i libri di testoAmerman 3rd EditionCh. 25 Fluid, Electrolyte, and Acid-Base HomeostasisProblema 18
Capitolo 25, Problema 18

How does angiotensin-II help to restore fluid balance when a person is dehydrated?

Guida verificata passo dopo passo
1
Understand that dehydration leads to a decrease in blood volume and blood pressure, which triggers the renin-angiotensin-aldosterone system (RAAS) to restore fluid balance.
Recognize that angiotensin-II is a key hormone in the RAAS pathway, produced when renin (from the kidneys) converts angiotensinogen (from the liver) into angiotensin-I, which is then converted to angiotensin-II by the enzyme angiotensin-converting enzyme (ACE) in the lungs.
Explain that angiotensin-II acts as a potent vasoconstrictor, narrowing blood vessels to increase blood pressure and improve circulation despite reduced fluid levels.
Describe how angiotensin-II stimulates the release of aldosterone from the adrenal glands, which promotes sodium reabsorption in the kidneys. Sodium reabsorption increases water retention, helping to restore blood volume.
Highlight that angiotensin-II also stimulates the release of antidiuretic hormone (ADH) from the posterior pituitary gland, which increases water reabsorption in the kidneys, further aiding in fluid balance restoration.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Angiotensin-II

Angiotensin-II is a peptide hormone that plays a crucial role in the body's fluid balance and blood pressure regulation. It is produced from angiotensinogen in response to low blood pressure or low blood volume. Angiotensin-II acts primarily by constricting blood vessels, which increases blood pressure, and stimulating the release of aldosterone, promoting sodium and water reabsorption in the kidneys.
Video consigliato:
Percorso guidato
11:30
Renin-Angiotensin-Aldosterone-System

Fluid Balance

Fluid balance refers to the equilibrium between the intake and output of fluids in the body, essential for maintaining homeostasis. When a person is dehydrated, the body loses more water than it takes in, leading to a decrease in blood volume and pressure. Restoring fluid balance involves mechanisms that increase water retention and promote fluid intake, ensuring that vital organs function properly.
Video consigliato:
Percorso guidato
07:16
Osmoregulation and Nitrogenous Waste

Aldosterone

Aldosterone is a steroid hormone produced by the adrenal glands that regulates sodium and potassium levels in the body. In response to angiotensin-II, aldosterone promotes the reabsorption of sodium in the kidneys, which in turn leads to water retention. This process helps to increase blood volume and restore fluid balance, particularly during states of dehydration.
Video consigliato:
Percorso guidato
11:30
Renin-Angiotensin-Aldosterone-System
Pratica correlata
Domanda del libro di testo

Which of the following statements correctly describe(s) the role of aldosterone?

a. Aldosterone triggers sodium ion and so water reabsorption.

b. Aldosterone triggers potassium ion secretion.

c. Aldosterone triggers hydrogen ion secretion.

d. Both a and b are correct.

e. All of the above are correct.

422
views
Domanda del libro di testo

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. Renal compensation for metabolic alkalosis consists of reabsorption of hydrogen ions and secretion of bicarbonate ions.

399
views
Domanda del libro di testo

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. You would expect to find an elevated Pco₂ in arterial blood gas analysis of a patient with respiratory acidosis.

335
views