Renin-Angiotensin-Aldosterone System (RAAS) Overview

Key Components and Processes

• Liver

  • Produces a pre-enzyme called Angiotensinogen.

• Kidney

  • Releases Renin due to low fluid volume.
  • Renin converts Angiotensinogen into Angiotensin I.

• Lungs

  • Angiotensin I is converted to Angiotensin II by the Angiotensin-Converting Enzyme (ACE).
  • ACE is found in the lungs.

Angiotensin II Actions

• Adrenal Gland

  • Stimulates release of Aldosterone (a steroid hormone).

• Kidneys

  • Aldosterone acts on the nephrons, specifically the collecting ducts, to retain water (H2O retention).
  • Leads to increased blood pressure.

• Heart

  • Contributes to inappropriate heart remodeling post-heart attack, increasing morbidity and mortality.

Drug Interventions

• ACE Inhibitors

  • Inhibit Angiotensin-Converting Enzyme.

• Angiotensin II Receptor Blockers (ARBs)

  • Also known as "-sartan" drugs.
  • Block effects of Angiotensin II.

• Aldosterone Antagonists

  • e.g., Spironolactone.

Clinical Implications

• Blood Pressure

  • Drugs lead to lower blood pressure.

• Heart Attack Outcomes

  • ACE inhibitors and ARBs prevent heart remodeling, improving post-heart attack outcomes.

Further Resources

• For free tutorials and PDF resources, visit handwrittentutorial.com