Manual of Surgery eBook

This eBook from the Gutenberg Project consists of approximately 697 pages of information about Manual of Surgery.

Manual of Surgery eBook

This eBook from the Gutenberg Project consists of approximately 697 pages of information about Manual of Surgery.

Hollow viscera, like the oesophagus and urinary bladder, in so far as they are not covered by peritoneum, heal less rapidly.

Nerve Tissues.—­There is no trustworthy evidence that regeneration of the tissues of the brain or spinal cord in man ever takes place.  Any loss of substance is replaced by cicatricial tissue.

The repair of Bone, Blood Vessels, and Peripheral Nerves is more conveniently considered in the chapters dealing with these structures.

#Rate of Healing.#—­While the rate at which wounds heal is remarkably constant there are certain factors that influence it in one direction or the other.  Healing is more rapid when the edges are in contact, when there is a minimum amount of blood-clot between them, when the patient is in normal health and the vitality of the tissues has not been impaired.  Wounds heal slightly more quickly in the young than in the old, although the difference is so small that it can only be demonstrated by the most careful observations.

Certain tissues take longer to heal than others:  for example, a fracture of one of the larger long bones takes about six weeks to unite, and divided nerve trunks take much longer—­about a year.

Wounds of certain parts of the body heal more quickly than others:  those of the scalp, face, and neck, for example, heal more quickly than those over the buttock or sacrum, probably because of their greater vascularity.

The extent of the wound influences the rate of healing; it is only natural that a long and deep wound should take longer to heal than a short and superficial one, because there is so much more work to be done in the conversion of blood-clot into granulation tissue, and this again into scar tissue that will be strong enough to stand the strain on the edges of the wound.

THE TRANSPLANTATION OR GRAFTING OF TISSUES

Conditions are not infrequently met with in which healing is promoted and restoration of function made possible by the transference of a portion of tissue from one part of the body to another; the tissue transferred is known as the graft or the transplant.  The simplest example of grafting is the transplantation of skin.

In order that the graft may survive and have a favourable chance of “taking,” as it is called, the transplanted tissue must retain its vitality until it has formed an organic connection with the tissue in which it is placed, so that it may derive the necessary nourishment from its new bed.  When these conditions are fulfilled the tissues of the graft continue to proliferate, producing new tissue elements to replace those that are lost and making it possible for the graft to become incorporated with the tissue with which it is in contact.

Dead tissue, on the other hand, can do neither of these things; it is only capable of acting as a model, or, at the most, as a scaffolding for such mobile tissue elements as may be derived from, the parent tissue with which the graft is in contact:  a portion of sterilised marine sponge, for example, may be observed to become permeated with granulation tissue when it is embedded in the tissues.

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Manual of Surgery from Project Gutenberg. Public domain.