Anatomy and Physiology Help Renal System NEED HELP FAST.

The Renal threshold of Glucose (RTG) is the blood glucose concentration at which glucose begins to be excreted by the kidneys into the urine. This usually occurs in healthy adults at approximately 9 - 10 mmol/L (162 - 180 mg/dL).

Link: https://biology-forums.com/definitions/index.php/Renal_threshold_of_glucose_(RTG)


Bunch of things, namely: Low ADH (anti-diuretic hormone), a decrease in plasma volume of 10–15% and/or an decrease in plasma osmolality of 2–3% results in dilute urine. Techically, a rise in plasma osmolality triggers thirst and the release of ADH; a drop in plasma osmolality inhibits thirst and ADH.

Here is the physiology behind it:

Sodium is pivotal to fluid and electrolyte balance and to the homeostasis of all body systems because it is the principal extracellular ion. While the sodium content of the body may be altered, its concentration in the ECF remains stable because of immediate adjustments in water volume. The regulation of the sodium-water balance is inseparably linked to blood pressure and entails a variety of neural and hormonal controls: (1) aldosterone—increases the reabsorption of sodium from the filtrate; water follows passively by osmosis, increasing blood volume (and pressure). The renin-angiotensin mechanism is an important control of aldosterone release; the juxtaglomerular apparatus responds to: (a) decreased stretch (due to decreased blood pressure), (b) decreased filtrate osmolality, or (c) sympathetic nervous system stimulation, resulting ultimately in aldosterone release from the adrenal cortex. (2) ADH—osmoreceptors in the hypothalamus sense solute concentration in the ECF: increases in sodium content stimulate ADH release, resulting in increased water retention by the kidney (and increasing blood pressure). (3) Atrial natriuretic peptide—released by cells in the atria during high-pressure situations, it has potent diuretic and natriuretic (sodium-excreting) effects; the kidneys do not reabsorb as much sodium (therefore water) and blood pressure drops.

Thank you so much.

llscott777, what did you end up getting for this: What is the maximum osmolality of the interstitial fluid?

The maximum osmolality of the interstitial fluid is 1200.

Thanks for sharing that, +1.