Title: Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology - WikiVet English
Headings: Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology
A Tribute to Nick Short
Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology
Contents
Introduction to Reabsorption
Proportion of Filtered Substances Reabsorbed in the Proximal Tubule
Epithelial Transport
Ions and Compounds
Sodium
Water
Potassium
Urea
Glucose
T Max and Splay
The Kidneys Role In Glucose Regulation
The Secretion of H+ and the Reabsorption of HCO3-
Reabsorption of HCO3-
Protein
Primary Active Secretion - Organic Acids and Bases
Calcium
Revision

Content: However after Tmax all the nephrons are at and above full capacity and therefore after this point any increase in filtered glucose is demonstrated linearly with that excreted. The Tmax for a 20Kg dog is approximately 170mg per minute or 220g per 24 hour period. The normal amount of glucose filtered in 24 hours should be 60g. The Kidneys Role In Glucose Regulation
The kidneys do not really regulate plasma glucose but their main aim is to preserve this valuable nutrient. It is only at very high levels which the kidneys play a role in helping to prevent any further rises in glucose via excretion. The Secretion of H+ and the Reabsorption of HCO3-
Secretion of H + and reabsorption of HCO 3+ in the Proximal Tubule
Secretion of H+
The secretion of H + in this section of the nephron is mainly a result of the Na + /H + exchanger
This is an antiporter in the apical membrane
Energy for this process is provided by the Na/K ATPase in the basolateral membrane
Therefore it is secondary active transport
The ATPase pumps sodium out of the cell into the interstitium
This maintains a low intracellular Na which creates a gradient for