Patho - Module 2 - Altered cellular and Tissue Biology

Adaptive cellular mechanisms function to: - correct answer Protect cells from injury Cellular atrophy involves: - correct answer Decrease in cell size. *Most common in skeletal muscle, heart, secondary sex organs, and the brain. Due to lack of nerve stimulation, an individual with damage to the spinal cord may experience atrophy to which organ? - correct answer Skeletal Muscles The process of cellular atrophy is accomplished through which process? - correct answer Formation of autophagic vacuoles. Autophagic vacuoles are membrane-bound vesicles within the cell that contain cellular debris nad hydrolytic enzymes. The level of hydrolytic enzymes rises rapidly in atrophy. The enzymes are isolated in autophagic vacuoles to prevent uncontrolled cellular destruction. Thus, the vacuoles form as needed to protect uninjured organelles from the injured organelles and are eventually taken up and destroyed by lysosomes. In compensatory hyperplasia, growth factors stimulate cell division in response to: - correct answer Tissue loss. (compensatory hyperplasia is an adaptive mechanism that enables certain organs to regenerate.) Hormonal hyperplasia occurs chiefly in: - correct answer Estrogen dependant organs, such as the breast and uterus. (Ex: after ovulation, estrogen stimulates the endometrium to grow and thicken in preparation for implantation. If pregnancy occurs, hormonal hyperplasia, as well as hypertrophy, enable the uterus to enlarge.) Pathologic Hyperplasia is the abnormal proliferation of normal cells, usually in response to: - correct answer excessive hormonal stimulation or growth factors on target cells.( Ex: Pathologic endometrial hyperplasia, which causes excessive menstrual bleeding, is under the influence of regular growth-inhibition controls. If these controls fail, hyperplastic endometrial cells can undergo a malignant transformation.) Pathologic hyperplasia can lead to: - correct answer neoplasia (cancer), dysplasia, metaplasia. In response to an increased workload, such as that caused by high blood pressure, myocardial cells in the left ventricle will adapt through which process: - correct answer Hypertrophy. (Physiologic hypertrophy) The process of muscle hypertrophy involves an increase in: - correct answer Protein synthesis. (Increase protein in cellular componet, not an increase in cellular fluid). Chronic infection of the cervix by the Human Papillomavirus results in cervical: - correct answer Dysplasia. (Abnormal changes in size, shape, and organization of mature cells.) Metaplasia involves the replacement of normal cells by: - correct answer Another type of cell. (Ex: Replacement of normal columnar ciliated epithelial cells of the bronchial lining by stratisfied squamous epithelial cells. The new cells do not secrete mucus or have cilia, causing loss of protection.) Metaplasia occurs in response to: - correct answer Cell injury from noxious stimuli - generated by cytokines and growth factors in cells environment. (Noxious stimuli is any thermal, mechanical, or chemical substance that causes injury.) The most common cause of hypoxic injury is: - correct answer Ischemia Tissue ischemia and a decrease in mitochondrial oxygenation result in: - correct answer Decreased ATP production. Injury to the endoplasmic reticulum due to hypoxic injury results in: - correct answer A decrease in protein synthesis - (Because of the lack of ATP, the sodium/potassium pump fails allowing sodium and water to enter the cell freely causing dilation of the ER. Dilation of the ER results in detachment of ribosomes from rough ER, reducing protein synthesis.) Lysosomal rupture during hypoxic injury leads to: - correct answer Autodigestion of cells. (lysosomal rupture is caused by cellular swelling.) Restoration of oxygen to oxygen-deprived tissues results in: - correct answer Referfusion injury -- Radicals (hydroxy, superoxide, hydrogen peroxide) further membrane damage and mitochondrial calcium overload.