Relative sizes of some cellular ultrastructural elements
1000 nanometers (nm) = 1 micrometer (µm)
1000 micrometers (µm) = 1 millimeter (mm)
| Structure | Thickness, distance, or diameter (nm) |
|---|---|
| cleft in gap junction | 2 |
| microfilaments (actin) | 5 - 7 |
| plasma membrane | 7 - 8 |
| intermediar filaments (neurofilaments, gliofilaments) | 8 - 12 |
| myosin | 12 - 15 |
| ribosomes | 15 - 25 |
| intercellular clefts in neuropil | about 20 |
| microtubules | 20 - 25 |
| glycogen granules | 30 |
| synaptic vesicles | 40 - 60 |
| periodicity in collagen | 50 - 60 |
| dense-core vesicles | 60 - 120 |
| nuclear pores | 90 |
| primary lysosomes | 100 - 200 |
| centriole | 100 - 250 |
| neurosecretory granules | 100 - 400 |
| mitochondria | 100 - 500 |
| cilia | 200 - 400 |
| human hair | 70,000 |