Most of the nephron is permeable to urea except for the cortical portion of the distal tubule. As the filtrate descends into the medulla, urea diffuses into the loop of Henle down its concentration gradient, causing the urea concentration in the tubule to rise.he loop of Henle. The loop of Henle is the portion of the kidney that creates the conditions by which the kidney can form concentrated urine (i.e. urine with an osmolality greater than plasma) later on in the nephron.
Battery Voltage : Normally a charged cell in rest is around 2.1 Volts which yields in 12.6 Volts for a charged battery at rest. When the battery is being charged by the car alternator the voltage will vary usually between 14 and 14.4 Volts.
The standard car battery in today's vehicles are rated at 12 volts. Each battery has six cells which are 2.1 volts each. A car battery is considered fully charged at 12.6 volts. When a battery drops voltage, even by a small amount, it makes a big difference. For instance, when a battery drops from 12.6 to 12.0 volts, its power drops from 100% to 25%! At 12.4 volts, a car battery is only 75% charged. At 12.2 volts, it's 50% charged.