Changes

Half the plasma calcium is bound to proteins so it is only the ionised form which is available for filtration.  Reabsorption of calcium occurs in the proximal tubule however the regulation of how much is reabsorbed occurs in the ascending limb of the loop of henle, the distal tubule and collecting ducts.

Half the plasma calcium is bound to proteins so it is only the ionised form which is available for filtration.  Reabsorption of calcium occurs in the proximal tubule however the regulation of how much is reabsorbed occurs in the ascending limb of the loop of henle, the distal tubule and collecting ducts.

===[[Glucose Homeostasis - Physiology| Glucose]]===

===Glucose===

Glucose is a small molecule and so it is filtered in the same concentrations as are found in plasma which is approximately 5mmol/l.  Reabsorption of glucose can only occur in the proximal tubule and occurs regardless of the concentration gradient as it is completed via [[Active Transport - Physiology#Secondary Active Transport|secondary active transport]]. It is reabsorbed using a [[Transport Proteins - Physiology#Co-Transporters|co-transporter]] with [[Sodium Homeostasis - Physiology|sodium]].  The realisation of the [[Active Transport - Physiology#Development of Potential Energy|potential energy]] produced from sodium moving from an area of high concentration to an area of low concentration is enough energy to transport glucose across the membrane into the epithelial cells.  The energy technically comes from the utilisation of ATP by the [http://w01.rvcwiki.wf.ulcc.ac.uk/images/e/ef/NaKATPaseA%2BP.jpg sodium/potassium] [[Transport Proteins - Physiology#ATPases|ATPase]] which keeps sodium concentrations within the epithelial cells low this giving the sodium in the lumen a high potential energy.

Glucose is a small molecule and so it is filtered in the same concentrations as are found in plasma which is approximately 5mmol/l.  Reabsorption of glucose can only occur in the proximal tubule and occurs regardless of the concentration gradient as it is completed via [[Active Transport - Physiology#Secondary Active Transport|secondary active transport]]. It is reabsorbed using a [[Transport Proteins - Physiology#Co-Transporters|co-transporter]] with [[Sodium Homeostasis - Physiology|sodium]].  The realisation of the [[Active Transport - Physiology#Development of Potential Energy|potential energy]] produced from sodium moving from an area of high concentration to an area of low concentration is enough energy to transport glucose across the membrane into the epithelial cells.  The energy technically comes from the utilisation of ATP by the [http://w01.rvcwiki.wf.ulcc.ac.uk/images/e/ef/NaKATPaseA%2BP.jpg sodium/potassium] [[Transport Proteins - Physiology#ATPases|ATPase]] which keeps sodium concentrations within the epithelial cells low this giving the sodium in the lumen a high potential energy.