Renal Physiology: Distal Convoluted Tubule

The first section of the distal convoluted tubule (DCT), characterized by sodium reabsorption and potassium secretion.

The later part of the DCT responsible for regulated reabsorption of water under the influence of hormones. It's also involved in fine-tuning the balance of potassium and calcium.

The process of moving substances from the blood into the tubular fluid of the nephron, primarily in the proximal convoluted tubule (PCT) and the loop of Henle.

The process of moving substances from the tubular fluid back into the blood, occurring mainly in the PCT and the loop of Henle.

The descending limb of the loop of Henle allows passive reabsorption of water due to high osmolality of the surrounding medullary interstitium.

The ascending limb of the loop of Henle actively reabsorbs sodium, potassium, and chloride ions and is impermeable to water.

A unique mechanism that concentrates urine by creating a gradient of osmolality in the medulla, facilitated by the ascending and descending limbs of the loop of Henle.

A network of capillaries that run parallel to the loop of Henle, helping to maintain the osmolar gradient in the medulla by exchanging solutes and water.

The process of maintaining a concentration gradient in the interstitial fluid of the medulla by counteracting the fluid flow in the loop of Henle.

The movement of substances across a membrane without the involvement of energy.

A steroid hormone produced in the adrenal cortex, aldosterone acts on the late distal convoluted tubule (DCT) to increase sodium reabsorption and potassium secretion, ultimately leading to increased blood pressure.

A hormone synthesized in the hypothalamus and released by the posterior pituitary gland, vasopressin (ADH) is also known as the 'antidiuretic hormone'. It plays a crucial role in regulating water reabsorption in the collecting duct by increasing the water permeability of the DCT and collecting duct, ultimately leading to concentrated urine.

Hypokalemia, or low potassium levels in the blood, triggers the release of aldosterone from the adrenal cortex. It's one of the primary stimuli for aldosterone production, ensuring potassium levels remain within a healthy range.

Aldosterone production is stimulated by the presence of angiotensin-I, a peptide hormone produced in the liver. This is part of the renin-angiotensin-aldosterone system (RAAS), a critical hormonal pathway regulating blood pressure and fluid balance.

A specialized protein pump located on the basolateral membrane of the early distal convoluted tubule (DCT) that actively moves sodium ions out of the cell and potassium ions into the cell. It requires ATP as an energy source.

A specialized transporter protein on the luminal membrane of the early DCT that facilitates the simultaneous movement of sodium and chloride ions into the cell.

A type of diuretic medication that inhibits the sodium-chloride symporter in the early DCT, leading to increased sodium and water excretion in the urine.

A hormone produced by the parathyroid gland in response to low blood calcium levels. It acts on the DCT to increase calcium reabsorption into the bloodstream.

A protein located on the DCT cell that binds to PTH, initiating a signaling cascade that ultimately increases calcium reabsorption.

A second messenger molecule that is produced inside DCT cells after PTH binds to its receptor. It activates protein kinase A, leading to increased calcium permeability of the cell membrane.

An enzyme activated by cAMP in DCT cells. It phosphorylates (adds a phosphate group to) calcium-modulated channels, increasing their permeability to calcium ions.

A protein that binds to calcium ions inside the DCT cells, helping to regulate intracellular calcium levels.

A protein transporter located on the basolateral membrane of the DCT that actively moves calcium ions out of the cell and sodium ions into the cell. It is a secondary active transport mechanism.

A protein transporter located on the basolateral membrane of the DCT that actively pumps calcium ions out of the cell using ATP as energy. It also moves hydrogen ions into the cell.

A protein channel located on the luminal membrane of the late DCT that is stimulated by aldosterone. It allows sodium ions to enter the cell from the urine.

A protein pump located on the basolateral membrane of the late DCT that is stimulated by aldosterone. It actively transports sodium ions out of the cell and potassium ions into the cell.

A protein channel located on the luminal membrane of the late DCT that is stimulated by aldosterone. It allows potassium ions to leave the cell and be excreted in the urine.

A hormone, also known as vasopressin, that can act on the late distal convoluted tubule (DCT). It increases water permeability by opening aquaporins, allowing water to follow the sodium and be reabsorbed into the bloodstream.

A protein channel that allows water to pass through cell membranes. They are stimulated by ADH in the late DCT, increasing water reabsorption.