Distal convoluted tubule

Distal convoluted tubule

Kidney nephron (labeled as "2nd convoluted tubule", near top)
Image:Gray1132.png
Section of cortex of human kidney.
Latin	tubulus contortus distalis
Gray's	subject #253 1223
Precursor	Metanephric blastema
MeSH	Distal+Kidney+Tubule
Dorlands/Elsevier	t_22/12830066

The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting duct system.

[edit] Physiology

It is partly responsible for the regulation of potassium, sodium, calcium, and pH.

It regulates pH by absorbing bicarbonate and secreting protons (H⁺) into the filtrate.

Sodium and potassium levels are controlled by secreting K⁺ and absorbing Na⁺. Sodium absorption by the distal tubule is mediated by the hormone aldosterone. Aldosterone increases sodium reabsorption. Sodium and chlorine (salt) reabsorption is also mediated by a group of kinases called WNK kinases. There are 4 different WNK kinases, WNK1, WNK2, WNK3, and WNK4.

It also participates in calcium regulation by absorbing Ca²⁺ in response to parathyroid hormone.<ref>Kidney function - Loyola University</ref>

Thiazide diuretics inhibit Na⁺/Cl^- reabsorption from the DCT.

Histologically, cells of the DCT can be differentiated from cells of the proximal convoluted tubule:

1 Glomerulus, 2 proximal tubule, 3 distal tubule

Transverse section of pyramidal substance of kidney of pig, the bloodvessels of which are injected.

Urinary system - Kidney - edit
Renal capsule \| Renal cortex \| Renal medulla (Renal sinus, Renal pyramids) \| Renal calyx \| Renal pelvis
Nephron - Renal corpuscle (Glomerulus, Bowman's capsule) → Proximal tubule → Loop of Henle → Distal convoluted tubule → Collecting ducts Juxtaglomerular apparatus (Macula densa, Juxtaglomerular cells, Extraglomerular mesangial cells) Renal circulation - Renal artery → Interlobar arteries → Arcuate arteries → Cortical radial arteries → Afferent arterioles → Glomerulus → Efferent arterioles → Vasa recta → Arcuate vein→ Renal vein
Renal physiology
Filtration - Ultrafiltration \| Countercurrent exchange Hormones effecting filtration - Antidiuretic hormone (ADH) \| Aldosterone \| Atrial natriuretic peptide Endocrine - Renin \| Erythropoietin (EPO) \| Calcitriol (Active vitamin D) \| Prostaglandins
Assessing Renal function / Measures of dialysis
Glomerular filtration rate \| Creatinine clearance \| Renal clearance ratio \| Urea reduction ratio \| Kt/V \| Standardized Kt/V \| Hemodialysis product