Biomedical Engineering Reference
In-Depth Information
quantitative in this field than in skin due to morphological differences between tis-
sues in the two organs.
The two organs, skin and peripheral nerves, are distinctly different from each
other; and so are also the experimental conditions employed to study regeneration
of each organ. One of my tasks in writing this volume is to demonstrate the intrinsic
similarity between the process of induced regeneration in skin and in peripheral
nerves. The evidence shows that certain basic spontaneous healing phenomena in
these two organs are practically identical, differing primarily in their topographic
anatomy; and that regeneration is induced in both of them using the same scaffold
(Soller et al. 2012). This finding justifies the search for
trans-organ rules
, to be used
in studying induced regeneration in other organs as well.
1.7
An Anatomically Well-Defined Wound
We now turn to consideration of the type of injury that will be studied in this vol-
ume.
The outcome of an injury in any organ depends profoundly on the precise nature
of wound that has been generated. Investigators have studied a large variety of
wound types, most of them not suited to the study of induced regeneration. In order
to build a useful database from studies of several independent investigations it is
necessary to select experiments that have been conducted with a type of wound that
is both standardized and appropriate to the purpose of the study. For this reason,
the vast majority of experimental data on spontaneous and induced regeneration
described in this volume have been drawn from these investigations in which a
specific type of
anatomically well-defined wound
, uniquely suited to the study of
induced regeneration, and described in detail in a later chapter, was studied.
In order to emphasize the restrictions applied in selecting a particular kind of
wound, as well as to discuss wounds in organs other than skin, I will use the term
defect
as shorthand to represent the anatomically well-defined wound that is appro-
priate for study of induced regeneration. Defects in skin and peripheral nerves will
be described later in this volume. Use of this term will hopefully provide instant
and relatively precise information to the reader about the anatomical site and extent
of injury in which the process of interest is taking place. The term “wound” will be
retained to denote the result of generalized injury without specification of the type
or extent of injury.
1.8
All Organs Can Be Irreversibly Injured
The experimental evidence shows that all organs in the adult can be irreversibly
injured. To support this statement we now survey the outcome of healing in a va-
riety of tissues and organs following injury. Only studies of spontaneous healing
events in adult mammals, unaided by devices and eventually leading to repair, are
reviewed below.
