CVPR Week 8: Acid-Base 3 Flashcards
Objectives
Describe metabolic alkalosis
Where is aldosterone produced?
by the adrenals (glands that lie on top of the kidneys) in the adrenal cortex in the zona glomerulosa)
Zones of the adrenal cortex
- Zona glomerulosa (the most outer layer)
- zona fasciculata
- zona reticularis
What are the stimuli for aldosterone release?
- High K+
- Volume depletion
Types of metabolic alkalosis
- Cl-/saline/volume sensitive metabolic alkalosis
- Cl-/Saline/volume resistant metabolic alkalosis
Cl-/saline/volume sensitive metabolic alkalosis
spot urine
Spot urine Cl <10
Cl-/saline/volume resistant metabolic alkalosis
Spot urine
Spot urine Cl >10
Pathogenesis of Cl- sensitive metabolic alkalosis
- Volume is decreased which results in decreased circulating Cl-
- the decreased circulating Cl- is sensed by the macula Densa which triggers synthesis and release of renin and angiotensin 2
- Angiotensin 2 increases the activity of the Na/H exchanger in the PCT resulting in H+ loss & increased aldosterone
- The increased aldosterone increases the activity of epithelial Na channel (ENaC) causing electrogenic Na+ absorption leading to lumen negativity and K+ loss
- The increased K/H activity to absorb more K+ leads to more H+ loss
- The lumen becomes more negative and Cl- and HCO3 are not excreted
Metabolic alkalosis Cl sensitive summary
Question 1
Cl- resistant metabolic alkalosis
Zona fasciculata of the adrenals make cortisol
Syndrome of apparent mineralocorticoid access
Compare and contrast Cl sensitive and Cl resistant metabolic alkalosis
Question 2
How do the lungs compensate for metabolic alkalosis
Question 3
Question 4
