© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

8.5.4 Nucleography

Nucleography is the "geography" of the cell nucleus. The nucleus, 5-8 microns in diameter for a 20 micron tissue cell and up to 10 microns for a fibroblast cell, is the largest cellular organelle and the only one that is voluminous enough, in theory, to admit a micron-scale medical nanorobot into its interior. The nucleus is usually a large spherical or ovoid structure surrounded by its own nuclear membrane, although its shape generally conforms to the shape of the cell. For example, if a cell is elongated, the nucleus may be extended as well.⁹⁴⁰

Almost all cells contain a single nucleus, whose primary function is the storage and expression of genetic information. However, a few cell types have multiple nuclei of similar size, such as skeletal muscle cells, osteoclasts, megakaryocytes, and some hepatocytes.⁹³⁵ A few cell types have no nucleus, such as red blood cells, platelets, keratinized squamous epidermal cells, and lens fibers.

In 1998 the finer details of nuclear structure were just beginning to be understood.¹⁵²⁹ Thus the following discussion of nucleography must be regarded as a very tentative work in progress.

Last updated on 20 February 2003