Pathophysiology

Pathophysiology Study Guide

©2018 of 131 hypothalamus cause fever. The pyrogens can be exogenous like LPS, which induce IL-1 and TN and lead to an increase in the conversion of AA into prostaglandins. Microbial infections can be shed due to the expression of leukocyte heat shock proteins during fever. Another manifestation of systemic inflammation is the synthesis of plasma proteins, like acute-phase proteins in the liver as a result of inflammatory cytokines, such as IL- 1, IL- 1, and TNF. Other acute- phase proteins, like C- reactive protein, serum amyloid A protein, and fibrinogen opsonize the microbes. This leads to the elevation in erythrocyte sedimentation rate (ESR) and becomes a sign of myocardial infarction. The number of lymphocyte from bone marrow in viral infections may also increase, triggered by the cytokines IL-1 and TNF, causing leukocytosis. When the number of lymphocytes increases to 100,000 cells/µl as compared to the normal range of 15,000-20,000 cells/µl, it fosters a leukemoid reaction. Other manifestations of systemic inflammation are the increase in blood pressure and pulse rate, fall in sweat, shivering, chills, anorexia, somnolence, malaise, and sepsis. 2.3 Alterations in Wound Healing Wound healing is a complex procedure that involves a number of stages. Most injured tissues are healed by regeneration or repair. With regeneration, the damaged tissues are replaced by identical cells, while repair takes place when the damaged tissues are replaced by connective tissues, which later convert into a scar. The stages of wound healing consist of inflammatory response, destructive phase, proliferation phase, and finally the re-modeling phase. However, there are some circumstances that impair this process of wound healing. Some of the factors are discussed below. Dysfunction in Inflammatory Response Generally, wounds are easily healed, but there are some situations when the healing process of the body is not regulated properly and wounds are not able to repair by following the normal sequence of the healing process. Healing is generally impaired when one or more stages of the healing process are disruptive. Such wounds do not repair in a timely fashion and also cause immense pain and suffering for the individual. One of the prime causes of this disruption is the malfunctioning of the inflammatory phase of wound healing, which often leads to infections, formation of sutures, or presence of debris and necrotic tissues. Some wounds do not undergo the normal inflammatory response and remain in the chronic inflammatory state. The reason for this could be systemic defects, as well as the presence of local stimuli, which generate a cascade of responses from tissues. One of the severe systemic effects that obstruct inflammatory response is pyoderma gangrenosum, where some of local stimuli could be tissue hypoxia, infections caused by bacteria, and necrotic tissues that can sustain a continued influx of neutrophils and macrophages. Further, these wounds secrete high concentrations of bioactive Achieve Page 28