Mechanism of Na Selective Reabsorption in Collecting Duct

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Mechanism of Na Selective Reabsorption in
Collecting Duct
Figure 20-12 Aldosterone action in principal
cells
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Table 20-1. Factors Affecting
Aldosterone Release Direct , at the
Adrenal Cortex Increased
extracellular (plasma) K concentration
Increased osmolarity Indirect, through
the Renin-Angiotensin-Aldosterone Pathway
Decreased blood pressure
Decreased tubular flow past the macula densa
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Angiotensin Pathway Maintains BP , Volume
Osmolarity Angiotensinogen, ANGI, ANG II, rennin,
ACE
Figure 20-13 The renin-angiotensin-aldosterone
pathway
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To be inserted
Figure 20-14. Decreased B.P. Stimulates Renin
Secretion
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Artial Natruretic Peptide Regulates Na H2O
Excretion
Figure 20-15 Atrial natriuretic peptide
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Figure 20-16. Disturbances of Volume and
Osmolarity
Osmolarity
Drinking large Amounts of water
Ingestion of large amounts of saline
Ingestion of hypertonic saline
Eating salt without drinking water
Replacement of sweat loss with plain water
Normal volume and osmolarity
Volume
Dehydration (e.g., sweat loss or diarrhea

Incomplete compensation for dehydration
Hemorrhage
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Response to Dehydration Osmolarity Imbalance
Figure 20-17 Homeostatic compensation for
severe dehydration
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Acid/Base Homeostasis Overview
PLAY
Animation Fluids Electrolytes Acid/Base
Homeostasis
Figure 20-18 Hydrogen balance in the body
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The Pulmonary System in Acid-Base
Regulation CO2 H2O H2CO3
H HCO3-
(2)
(1)
H (1)
H (2)
(1) Add acid Equilibrium shifts to the left,
pCO2 increases, and ventilation is
stimulated (2) Remove acid Equilibrium shifts
to the right, pCO2 decreases, and ventilation is
suppressed
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To be inserted
Figure 20-19.
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To be inserted
Figure 20-20
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Kidney Hydrogen Ion Balancing Proximal Tubule
Figure 20-21 Proximal tubule secretion and
reabsorption of filtered HCO3-
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Kidney Hydrogen Ion Balancing Collecting Duct
Figure 20-22 Role of the intercalated cell in
acidosis and alkalosis
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Table 20-3. Plasma pCO2, ions, and pH in
Acid-Base Disurbances
Disturbance pCO2 H pH HCO3- Acidosis
Respiratory Metabolic
Normal or Alkalosis
Respiratory Metabolic
Normal or