loading the kidneys — BodyParts3D kidneys, vessels and bones…

ACT 01 · THE KIDNEYS — two fists of filter, a fifth of your blood

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Two kidneys, each about the size of a fist, tucked against the back wall of the abdomen under the lowest ribs — the right one a little lower, pushed down by the liver. Together they weigh about 300 g, half a percent of the body, and they take about a fifth of everything the heart pumps. Every day they filter about 180 litres of plasma, and hand back all but one or two litres of it.

  • SCAN Kidneys, adrenal glands, bladder, arteries, veins and the bones around them: BodyParts3D 4.0, one adult male, in their measured positions.
  • MODEL The ureters are not in the scan's organ set; they are drawn on their textbook course from each hilum to the bladder. The pulse along the arteries is a drawing of flow, not a measurement.
sources
  • BodyParts3D 4.0, © The Database Center for Life Science (DBCLS), CC BY-SA 2.1 Japan — the kidneys, adrenals, bladder, vessels and bones.
  • Frick A, Eriksson UK, de Mattia F, et al. X-ray structure of human aquaporin 2 and its implications for nephrogenic diabetes insipidus and trafficking. PNAS 2014;111:6305–6310. Coordinates: RCSB PDB 4NEF (CC0).
  • Hall JE, Hall ME. Guyton and Hall Textbook of Medical Physiology, 14th ed., 2021 — GFR ~125 mL/min (~180 L/day); renal blood flow ~1,100 mL/min (~22 % of cardiac output); urine 1–1.5 L/day; Starling forces; filterability table; water reabsorption by segment; urine 50–1,200 mOsm/L; ~90 % of EPO renal; bicarbonate and acid balance.
  • Hughson M, Farris AB, Douglas-Denton R, Hoy WE, Bertram JF. Glomerular number and size in autopsy kidneys: the relationship to birth weight. Kidney Int 2003;63:2113–2122 — mean 901,902 nephrons per kidney, range 210,332–2,702,079.
  • Bertram JF, Douglas-Denton RN, Diouf B, Hughson MD, Hoy WE. Human nephron number: implications for health and disease. Pediatr Nephrol 2011;26:1529–1533.
  • Standring S (ed.). Gray's Anatomy, 42nd ed., 2020 — kidney size, position and weight.
  • Satchell SC, Braet F. Glomerular endothelial cell fenestrations: an integral component of the glomerular filtration barrier. Am J Physiol Renal Physiol 2009;296:F947–F956.
  • Haas M. Alport syndrome and thin glomerular basement membrane nephropathy: a practical approach to diagnosis. Arch Pathol Lab Med 2009;133:224–232 — normal adult basement-membrane thickness.
  • Rodewald R, Karnovsky MJ. Porous substructure of the glomerular slit diaphragm in the rat and mouse. J Cell Biol 1974;60:423–433; Wartiovaara J et al. Nephrin strands contribute to a porous slit diaphragm scaffold as revealed by electron tomography. J Clin Invest 2004;114:1475–1483.
  • Zeidel ML, Ambudkar SV, Smith BL, Agre P. Reconstitution of functional water channels in liposomes containing purified red cell CHIP28 protein. Biochemistry 1992;31:7436–7440 — ~3 × 10⁹ water molecules per second per AQP1 channel; Agre P, Nobel Lecture 2003.
  • Sui H, Han BG, Lee JK, Walian P, Jap BK. Structural basis of water-specific transport through the AQP1 water channel. Nature 2001;414:872–878 — the ~2.8 Å aromatic/arginine constriction; Murata K et al. Nature 2000;407:599–605.
  • de Groot BL, Grubmüller H. Water permeation across biological membranes: mechanism and dynamics of aquaporin-1 and GlpF. Science 2001;294:2353–2357; Tajkhorshid E et al. Control of the selectivity of the aquaporin water channel family by global orientational tuning. Science 2002;296:525–530.
  • Fushimi K et al. Cloning and expression of apical membrane water channel of rat kidney collecting tubule. Nature 1993;361:549–552; Nielsen S et al. Aquaporins in the kidney: from molecules to medicine. Physiol Rev 2002;82:205–244 — ADH, V2 receptor and AQP2 trafficking.
  • Benedict WS, Gailar N, Plyler EK. Rotation–vibration spectra of deuterated water vapor. J Chem Phys 1956;24:1139–1165 — water's geometry; Shimanouchi T. Tables of Molecular Vibrational Frequencies, NSRDS-NBS 39, 1972; Clough SA, Beers Y, Klein GP, Rothman LS. Dipole moment of water from Stark measurements of H2O, HDO, and D2O. J Chem Phys 1973;59:2254–2259 — 1.85 D.
  • Jorgensen WL, Chandrasekhar J, Madura JD, Impey RW, Klein ML. Comparison of simple potential functions for simulating liquid water. J Chem Phys 1983;79:926–935; Bondi A. van der Waals volumes and radii. J Phys Chem 1964;68:441–451.
  • Maxwell PH et al. Identification of the renal erythropoietin-producing cells using transgenic mice. Kidney Int 1993;44:1149–1162; Nobel Prize in Physiology or Medicine 2019 (Kaelin, Ratcliffe, Semenza) — oxygen sensing by HIF.
  • Bikle DD. Vitamin D metabolism, mechanism of action, and clinical applications. Chem Biol 2014;21:319–329 — CYP27B1 in the proximal tubule; PTH and FGF23 control.
  • Hamm LL, Nakhoul N, Hering-Smith KS. Acid–base homeostasis. Clin J Am Soc Nephrol 2015;10:2232–2242.
  • Sender R, Fuchs S, Milo R. Revised estimates for the number of human and bacteria cells in the body. PLoS Biol 2016;14:e1002533 — ~25 trillion red cells; with a ~120-day life (Guyton) that is ~2 million made per second.

Anatomy: BodyParts3D, © The Database Center for Life Science, licensed CC BY-SA 2.1 Japan; the derived meshes (public/anatomy/kidneys.glb) are re-shared under the same licence. Protein: RCSB PDB 4NEF, CC0.

EDUCATION ONLY Education only — not medical advice. Drugs and conditions are named only to explain the physiology; nothing here is a recommendation. With symptoms or questions about your kidneys, see a doctor.Not medical advice. With symptoms, see a doctor.