A pathologist uses monoclonal antibodies against several intermediate filament proteins and finds that a tumor section stains positive for cytokeratin only. The tumor most likely originated from which of the following tissues? (A) Connective (B) Epithelial (C) Glial (D) Muscle (E) Nemal

Cancer is a complicated series of diseases characterized by over-proliferation of cells within a tissue. While in some instances the primary tumor is the ultimate cause of death, in many cases the primary tumor metastasizes, or moves, through the lymph system to invade other tissues. The migration of tumor cells requires changes in the adhesion properties of the cell that allow it to move and invade more readily.  There are several molecules involved in cell-to-cell connections and cellular architecture: laminins, matrix metalloproteinases, cadherins, and integrins. While mutations in genes that control the cell cycle or recognize DNA damage are the causes of tumor cell formation, tumor cell spread to other tissues may be caused by mutations in the genes the code for these extracellular proteins. The loss of cellular connections, cellular identification and signaling, and tissue structure may lead to the release of expanding tumor cells into the circulatory and lymphatic systems. Once…

Which of the following cell-types are most likely to secrete Matrix Metalloproteases (MMPs) that remodel ECM near tumor (select all that apply)?   A. Carcinoma Cells   B. Mast cells   C. Normal Epithelial Cells   D. Macrophages   E. Fibroblasts

Stem cells responsible for the process of lymphocytopoiesis are located in the(a) thymus and spleen. (b) lymph nodes. (c) red bone marrow. (d) a, b, and c are correct.

What is over time, tumors tend to grow faster and become more invasive of other tissues?

If your skin is damaged by a cut a)  cells will repair themselves. b)  white blood cells will turn into new skin cells. c)  damaged cells will leak out and cause inflammation. d)  cells will be instructed to destroy themselves.

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A 10-year-old boy undergoes an appendectomy. Granulation tissue develops normally at the incision site. Tissue remodeling begins at this site with degradation of collagen in the extracellular matrix by which of the following proteins? (A) Cytokines (B) Lipoxygenases C Metalloproteinase (D) Nitric oxide (E) Plasminogen activator