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 |
|