John H. Holliman

Principles of Cell/Tissue Injury

The viability of a cell is dependent on its ability to produce energy, to manufacture essential proteins, to maintain its structural integrity and, in most cases, to replicate. Interference with any of these functions can affect the entire cell and may be reflected by structural, biochemical, or molecular changes within the cell which may ultimately be expressed as clinical signs and symptoms of “disease”. “Health”, therefore, depends on the ability of cells to maintain structural and functional stability (a steady state) in the face of a constantly changing microenvironment, a process termed homeostasis.

Principles of Inflammation

The inflammatory host defense reaction may be evoked by any insult or injury to the body tissues and involves vascular, neurologic, and cellular responses to a variety of chemical mediators. Only occasionally however does the inflammation become severe enough to be clinically evident. The inflammatory process is designed to destroy, dilute, or contain the injurious agent and prepare the tissue for repair, but like other self-protective mechanisms, exuberance of the inflammatory response can itself result in significant tissue damage.

Principles of Host Defense

The two major defense mechanisms of the body against potentially injurious events are the inflammatory response and the immunologic response. The cells involved in host defense are, in general, initially derived from the bone marrow and circulate through the peripheral bloodstream and lymphatic system or are “fixed” at certain sites throughout the body.

Principles of Wound Healing and Tissue Repair

As a continuation of the inflammatory process, wound healing is a phenomenon consisting of sequentially controlled steps which result in the replacement of dead tissue with regenerated cells and/or scar tissue. If the injury did not involve structural damage to the tissue, regeneration of new cells can restore original function (resolution). In most instances, however, there is at least some degree of connective tissue scarring and functional impairment of the involved tissue (organization). Understanding of the injury-repair process is important to be able to facilitate those factors that promote wound healing and minimize those factors that inhibit wound healing.

Female Genital Tract

The vulva is prone to infection because of warm, damp environment and effects of estrogen. Relative hypoestrinism in prepubertal and post menopausal women tends to decrease vulvar blood supply resulting in epithelial atrophy with decreased cornification. This makes vulva more prone to trauma and infection.

Fluid, Hemodynamic, and Coagulation Disorders

Edema — refers to the accumulation of excess fluid in the interstitial (extracellular and extravascular) spaces or body cavities. May be localized to a specific region (ascites, hydrothorax pericardial effusion etc.) or may be systemic (anasarca). May consist of protein-poor transudate or protein-rich (inflammatory) exudate.

Inflammation and Repair

Inflammation is the reaction of living tissues to various forms of injurious stimuli. It involves vascular, neurologic, humoral and cellular responses. The inflammatory process is designed to destroy, dilute or contain the injurious agent and pave the way for repair.