loading the head — 162,000 triangles of scan…

SMELL & TASTE · ACT 01

THE NOSE

a real head, cut down the middle

A real head, split down the middle with the septum lifted out, so you look at the side wall of the right nasal cavity. Air comes in over three scrolls of bone, the conchae. Most of each breath runs along the floor; only a small part curls up into the narrow cleft under the roof, where the smell receptors are. A sniff sends more of it there.

  • SCANSkull, conchae, septum, brain, tongue, teeth and skin: BodyParts3D, the subject's right half, cut at the midline.
  • DRAWNThe airflow streams. Their routes follow the scan's cavity; their speeds are illustrative.
  • FACTOnly a small part of each quiet breath reaches the olfactory cleft; sniffing raises the share.
sources
  • BodyParts3D 4.0, © The Database Center for Life Science (DBCLS), CC BY-SA 2.1 Japan — the head, brain and tongue.
  • Billesbølle CB, de March CA, van der Velden WJC, et al. Structural basis of odorant recognition by a human odorant receptor. Nature 2023;615:742–749. Coordinates: RCSB PDB 8F76 (CC0).
  • Buck L, Axel R. A novel multigene family may encode odorant receptors: a molecular basis for odor recognition. Cell 1991;65:175–187 — Nobel Prize in Physiology or Medicine 2004.
  • Malnic B, Godfrey PA, Buck LB. The human olfactory receptor gene family. PNAS 2004;101:2584–2589 — 339 intact genes, 297 pseudogenes. Niimura Y, Nei M: about 390–400 intact genes by other criteria.
  • Malnic B, Hirono J, Sato T, Buck LB. Combinatorial receptor codes for odors. Cell 1999;96:713–723.
  • Maresh A, Rodriguez Gil D, Whitman MC, Greer CA. Principles of glomerular organization in the human olfactory bulb. PLoS One 2008;3:e2640 — >5,500 glomeruli, ~16:1.
  • Willander J, Larsson M. Smell your way back to childhood: autobiographical odor memory. Psychon Bull Rev 2006;13:240–244.
  • Chaudhari N, Roper SD. The cell biology of taste. J Cell Biol 2010;190:285–296 — 50–100 cells per bud, cell types.
  • Chandrashekar J, Hoon MA, Ryba NJP, Zuker CS. The receptors and cells for mammalian taste. Nature 2006;444:288–294 — receptors; no tongue map.
  • Teng B et al. Cellular and neural responses to sour stimuli require the proton channel Otop1. Curr Biol 2019; Zhang J et al. Sour sensing from the tongue to the brain. Cell 2019.
  • Chandrashekar J et al. The cells and peripheral representation of sodium taste in mice. Nature 2010;464:297–301.
  • Perea-Martinez I, Nagai T, Chaudhari N. Functional cell types in taste buds have distinct longevities. PLoS One 2013;8:e53399.
  • Small DM, Prescott J. Odor/taste integration and the perception of flavor. Exp Brain Res 2005;166:345–357.
  • Rozin P. 'Taste–smell confusions' and the duality of the olfactory sense. Percept Psychophys 1982;31:397–401.
  • Spence C. Just how much of what we taste derives from the sense of smell? Flavour 2015;4:30.
  • Bushdid C, Magnasco MO, Vosshall LB, Keller A. Humans can discriminate more than 1 trillion olfactory stimuli. Science 2014;343:1370–1372.
  • Gerkin RC, Castro JB. The number of olfactory stimuli that humans can discriminate is still unknown. eLife 2015;4:e08127.
  • Meister M. On the dimensionality of odor space. eLife 2015;4:e07865.

Anatomy: BodyParts3D, © The Database Center for Life Science, licensed CC BY-SA 2.1 Japan; the derived head mesh (public/smell/head.glb) is re-shared under the same licence. Molecule: RCSB Protein Data Bank entry 8F76, CC0. Drawn and modelled parts are labelled on the page.

Education only, not medical advice. A lost or changed sense of smell or taste can have many causes — infections, injury, medicines, other illness — and is worth raising with a doctor.

EDUCATION ONLYNot medical advice.