Biomedical Engineering Reference
In-Depth Information
Geometry plays an important role in cellular mechanics. Thery
and Bornens noted that cell rounding is a common feature of cell
division where cells can adjust their volume or surface. They also
noted stiffening of the plasma membrane cortex and positioning
of the spindle poles. Part of this may involve the transmembrane
proteins becoming rigid helices. All these mechanisms indicate
relatively strong forces in balance. Kleckner et al. found similar
findings for chromosomes. In the EM domain SFT balances E and H
fields.Thismayapplytometaphasetoformatheoreticaldescription
of the stiffening and eventual rupturing of the chromosomes
into chromatids in particular bonds oriented in the north-south
direction defined by the spindle poles. SFT reveals a new level
of detail concerning the photon in its role as a mediator of EM
energy inside atoms and molecules. The neighbouring cells, both
in the north-south and in the east-west plane, play a role in
amplifying the initial north-south currents caused by the spindle
poles and the east-west currents within the chromosomes inside
the central cell. The combined enhanced E field is applied across
the membrane of this initial cell and then relayed along the
length of microtubules from the spindle pole to the chromosomes.
Metaphasedoesnotcontinueontoanaphaseuntiltheneighbouring
cells amplify the original tiny level of extracellular polarisation
and magnetisation to a su
cient level to rupture the centromere
bonds. The sister chromatids with their chromosome arms have
a central region containing heterochromatin and the centromere.
Attached to the centromere on both north and south sides is the
outer kinetochore that binds to the microtubules north and south.
The centromere occupies a central region, north-south, east-west
within the chromosome structure that is symmetric relative to
both chromatids holding the two sister chromatids together. The
central bond in this region is the one eventually broken, allowing
the chromatids to be pulled north or south to their spindle poles
(Fig. 1.18).
Therearemanyissuesconcerninghumanreproduction.Astrong
correlation exists between industrialisation, fertility and birth rate
across the globe, highlighted by a sharp distinction between the
underdeveloped and industrialised worlds. The replacement rate of
just over two children per family is the exception rather than the
