Altered Cellular and Tissue Biology

Metaplasia - correct answer Metaplasia is the reversible replacement of one mature cell type by another immature cell. The best example of metaplasia is replacement of normal columnar ciliated epithelial cells of the bronchial lining by stratified squamous epithelial cells. Causative factors of atrophy - correct answer aging, disuse, or reduced/absent blood supply, hormonal stimulation, or neural stimulation Causative factors of hypertrophy - correct answer commonly seen in left ventricle of heart in response to hypertension Causative factors of Hyperplasia - correct answer bladder response seen in patients with BPH (benign prostatic hyperplasia) Causative factors of Metaplasia - correct answer chronic irritation in lungs Causative factors of Dysplasia - correct answer persistent severe injury in the lungs (e.g. due to smoking) Metaplasia vs Dysplasia - correct answer Metaplasia is chronic injury or irritation while dysplasia is persistent severe injury or irritation What is the most common cause of cellular injury? - correct answer hypoxia Describe the mechanism of cellular injury that can occur as a result of the following causes: hypoxia, free radicals, and reactive oxygen species. - correct answer hypoxia can lead to inflammation OR that the opposite can be true - inflammation can lead to hypoxia Reversible vs. Irreversible injury - correct answer The normal cell responds to physiologic and pathologic stresses by adapting (atrophy, hypertrophy, hyperplasia, metaplasia). Cell injury occurs if the adaptive responses are exceeded or compromised by injurious agents, stress, and mutations. The injury is reversible if it is mild or transient, but if the stimulus persists the cell suffers irreversible injury and eventually death. Reperfusion Injury - correct answer Without oxygen, or anoxia, the cells display hypoxic injury and become swollen. With reoxygenation, reperfusion injury increases because of the formation of reactive oxygen radicals that can cause cell necrosis. Antioxidant mechanisms - correct answer Generation of Reactive Oxygen Species and Antioxidant Mechanisms in Biologic Systems. The three reactive oxygen species cause free radical damage to lipids (peroxidation of the membrane), proteins (ion pump damage), and DNA (impaired protein synthesis). The major antioxidant enzymes include superoxide dismutase, catalase, and glutathione peroxidase. Contusion - correct answer bleeding into tissues after a trauma Abrasions - correct answer scrapes Laceration - correct answer tearing of skin Hematoma - correct answer subdural (beween brain and dura), epidural (between skull and dura) Significant Adaptive Stages of Cells - correct answer -Atrophy -hypertrophy -hyperplasia -metaplasia What causes Atrophy? - correct answer decrease in cellular size caused by aging, disuse or lack of blood supply, hormonal stimulation, or neural stimulation. What causes hypertrophy? - correct answer -increase work demands or hormonal stimulation -commonly seen in left ventricle of heart in response to hypertension Hyperplasia - correct answer -increased rate of cellular division -bladder response seen in patients with BPH (benign prostatic hyperplasia) -normal hyperplasia is stimulated when we need to replace lost tissue Metaplasia - correct answer reversible replacement of one mature cell type by another less mature cell -chronic irritation in lungs Dysplasia - correct answer abnormal change in size, shape, and organization of mature cell. -severe injury in the lungs due to smoking -persistent or severe injury or irritation Hypoxia can lead to inflammation in... - correct answer -pulmonary edema -Cancer -Organ transplantation -Adipose tissue Inflammation can lead to hypoxia in... - correct answer -acute lung injury -colitis -infections with pathogens Reperfusion injury - correct answer restoration of oxygen can