Principles lec 7 2013

2 necrosis uncontrolled cell death death where

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Unformatted text preview: Necrosis: uncontrolled cell death death, where release of cellular components into the surrounding the release of this is bad for the surrounding cells Toxic insult caused irreversible cell injury. Death is rapid and destructive destruction spreads throughout the tissue Uncontrolled, cell releases digestive enzymes and other factors that affect surrounding cells Toxicosis … the cellular response 14 i.e. the skin the surrounding cells recycle components of the dying cell 3. Apoptosis: Programmed cell death Non- destructive / controlled Happens naturally (skin cells), Cells are phagocytosed by other cells, building blocks are recycled, no digestive enzymes released. cellular death in a controlled manner also used as a final line of defense, when dying or during cancer used as a way to save its neighbours 4. Cancer • Excessive cell growth (lack blood supply) • Unresponsive (invasive/metastatic) • Non-functional (lack of differentiation) cells grow uncontrolled have no funciton and provide no benefit to the host Uncontrolled cell growth and division that will use up resources of healthy cells Chemical-Target Interactions (Review) 15 How does a toxicant exert its effects? • Bind with a protein •Affect mechanism of action, block binding site •Alter physical characteristics, change folding or binds to another location on the protein so that it changes the shape and nothing else can bind to it distrupting homeostasis of cells • Disrupts or accentuates normal cell processes •Bind to receptor that up-regulates/ inhibits transcription, affect protein levels decrease in compartmentalization of cells • Interact with Lipids •Physical damage to structure and orientation (lipid peroxidation) • Affects DNA •Bind irreversibly to DNA to affect Watson and Crick base pairing (DNA adducts) •Cut DNA backbone (radical hydrogen abstraction) • Oxidize DNA bases to change their structure also affecting protein synthesis and cellular division, which can lead to cancer and other cellular affects Toxicosis … organ / body function 16 ALTERED ORGAN and BODY FUNCTION permenant = replace non-specific = take away stimulus loss of function of these cells and therefore loss of function of organs leads to a greater affect on the body Pathophysiology Study of altered physiological processes to explain the clinical signs (toxicosis) ob...
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This document was uploaded on 04/07/2014.

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