Renal Regulation of Electrolytes Quiz

The amount of potassium ions present in the extracellular fluid, normally around 4.2 mEq/L. Small changes can significantly affect cell function.

Total serum calcium ranges from 8.4 to 10.2 mg/dL, made up of ionized, protein-bound, and complexed calcium.

Physiologically active form of calcium involved in muscle contraction, blood coagulation, and intracellular adhesion.

Calcium bound to proteins, mainly albumin in the blood. Hypoalbuminemia can falsely lower serum calcium levels.

Calcium absorption happens in the intestines via two mechanisms: paracellular (passive, significant at high intake) and transcellular.

Potassium is mostly reabsorbed in the proximal tubule and ascending loop of Henle, leaving a small amount in the distal tubule.

Calcium exists in three compartments: Ionized, Protein-bound, and Complexed (with inorganic compounds).

A condition where there is a low level of albumin in the blood, potentially causing a falsely low calcium reading.

Cholecalciferol, produced in the skin upon exposure to sunlight and crucial for calcium absorption.

The active form of vitamin D, also known as 1,25(OH)2D3, plays a key role in calcium absorption and bone metabolism.

Synthetic derivatives of vitamin D, like doxercalciferol and paricalcitol, used to treat hypocalcemia.

Maintaining normal phosphorus levels is crucial for healthy bones, energy production, and cell function.

The majority of phosphorus (85%) is stored in bones, with smaller amounts in cells and extracellular fluid.

Phosphorus is absorbed in the intestines through two major mechanisms: paracellular (passive) and transcellular (active).

The kidneys play a crucial role in regulating phosphorus levels, ensuring enough is reabsorbed and excess is excreted.

Various factors, including hormones and dietary intake, influence how the kidneys handle phosphorus.

The total amount of calcium in the body is around 1,000-1,200 grams, with 99% stored in bones and 1% in fluids. This 1% is what keeps calcium levels balanced and helps maintain various body functions.

The levels of calcium in the body are tightly controlled by several factors, including calcitriol (a vitamin D hormone), parathyroid hormone, and the kidneys.

A hormone secreted by the parathyroid glands that increases calcium levels in the blood by encouraging release from bones and increasing reabsorption in the kidneys.

The kidneys play a crucial role in calcium regulation, filtering and reabsorbing calcium to maintain a healthy balance in the blood. Only the ionized and complexed forms of calcium are affected by the kidneys.

Different sections of the nephron, the functional unit of the kidneys, are responsible for reabsorbing varying amounts of calcium. The proximal convoluted tubule reabsorbs the most, followed by the loop of Henle and distal convoluted tubule.

The proximal tubule reabsorbs calcium through passive diffusion, where calcium moves along the concentration gradient, and active transport, where energy is used to move calcium against the gradient.

The thick ascending loop of Henle reabsorbs calcium through a paracellular mechanism, meaning calcium moves between cells rather than through them.

The collecting duct reabsorbs calcium through a transcellular mechanism, meaning calcium moves through the cells, requiring specific transporters.

A protein on the surface of cells, especially in the parathyroid glands and kidneys, that detects changes in calcium levels and triggers responses to maintain balance.

The kidneys reabsorb approximately 98% of filtered phosphorus, primarily in the proximal tubule, with smaller contributions from the loop of Henle, distal tubule, and collecting duct.

In the distal convoluted tubule, magnesium is reabsorbed actively through the cells, a process dependent on potassium and sodium transport.

Dietary restriction, parathyroid hormone (PTH), glucagon, calcitonin, vasopressin, aldosterone, amiloride, metabolic alkalosis, and epidermal growth factor (EGF) all increase magnesium absorption.

Hypermagnesemia, metabolic acidosis, phosphate depletion, loop and thiazide diuretics, aminoglycosides, amphotericin, cisplatin, tacrolimus, and cyclosporine all decrease magnesium absorption.

Thiazide diuretics, acting on the NCC channel in the distal convoluted tubule, can cause hypomagnesemia (low magnesium levels) by interfering with magnesium reabsorption.

Acids release hydrogen ions (H+) when dissolved in water, while bases accept hydrogen ions.

The thick ascending limb of Henle (TALH) handles a significant portion of magnesium reabsorption (40-70%), using a paracellular mechanism similar to calcium.

Calbindin, a protein found within cells, acts as a 'sink' to lower intracellular calcium concentration, facilitating calcium transport across the cell.

Acids that can be easily removed from the body, primarily through the lungs as carbon dioxide (CO2).

Acids that cannot be easily removed from the body through the lungs. They are primarily excreted by the kidneys.

Carbonic acid, a volatile acid produced in the body from carbon dioxide (CO2) and water (H2O).

Bicarbonate ion, a base that can accept H+ to form H2CO3, acting as a buffer in the body.

A condition where there is an excess of H+ in the body fluids, leading to a lower than normal pH.

A condition where there is a decrease in H+ in the body fluids, leading to a higher than normal pH.

The normal range for blood pH is 7.35 to 7.45. Values outside this range can indicate serious health problems.

The pH of urine can vary depending on the body's acid-base balance, ranging from 4.5 to 8.0.

Acids from food sources contribute to the overall acid load in the body.

Metabolic processes in cells generate carbon dioxide (CO₂), which is acidic and impacts blood pH.

Inflammation of the glomeruli in the kidneys caused by an immune reaction, often triggered by streptococcal infection.

Antibodies react with antigens, forming complexes that get trapped in the glomeruli, causing damage.

Destruction of epithelial cells in renal tubules, leading to kidney injury, caused by toxins or medications.

Substances like carbon tetrachloride, heavy metals, ethylene glycol, and some medications can cause ATN.

Destruction of epithelial cells in renal tubules, disrupting filtration and causing acute kidney injury.