Gen Path Exam 1 Flashcards
Hypoxia
an organ is not receiving adequate oxygen within the arterial blood supplying the organ.
Often, hypoxia results from _______.
Ischemia. But Hypoxia can also develop when ischemia is not present such as pneumonia, carbon monoxide poisoning, or a disease that inhibits the movement of the thorax.
Cyan
A bluish discoloration of the skin which may develop following tissue ischemia or hypoxia.
Infection
Microbes directly induce tissue damage or when microbes stimulate an excessive immune response which injures tissues.
Immunological reaction
Over-activation of the normal immune mechanisms may injury cells via autoimmunity or allergies. These are commonly referred to as hypersensitivity reactions and the injury to cells comes in the form of inadvertent damage to normal cells as results of excessive or uncontrolled immune reaction.
Trauma
Cell and tissue injury may result from mechanical trauma, thermal trauma, electrical injury, or injury from high-energy radiation.
Aging
The reduced capacity for cells to react to stress and maintain homeostasis is known as cellular senescence.
Reversible cellular injury
Cellular swelling (not enough ATP which results in accumulation of ions within cell) and fatty change (steatosis) (accumulation of lips vacuoles within a cell’s cytoplasm)
The primary organ known to manifest with fatty change following injury
Liver (hepatic injury can be caused by excessive alcohol use or diabetes)
Cellular death is associated with what three things?
- Significant mitochondria damage, 2. damaged plasma membrane, 3. genetic/nuclear damage
Cellular death occurs what two pathways?
- apoptosis, 2. necrosis
Apoptosis is useful when…..
- unrated cells during development, 2. tissue homeostasis, 3. severe DNA damage, 4. severe protein damage, 5. a loss of cellular survival signals, 6. cells that have been infected by viruses
Morphologic features are observed when a cell undergoes necrosis. These changes are primarily observed in the _______ and ________.
Cytoplasm and nucleus
Name two cytoplasmic changes that take place during necrosis and describe what they are.
- Eosinophilia: necrotic cells manifest with an increased pink or red appearance with standard hematoxylin and eosin (H&E) stain. 2. Myelin figures: necrotic cells contain membrane damage and myelin figures are rolled-up or scroll-like area of the lipid bilayer that is within a cell. These findings require an electron microscope to be seen. Myelin figures are not involved with actual myelin, just resembling.
Name three nuclear changes that take place during necrosis and describe what they are.
- Pyknosis: nuclear shrinkage and increased basophilia (blue-staining or darker appearance), due to nuclear DNA condensing.
- Karyorrhexis: after pyknosis, it will fragment or fall apart.
- Karyolysis: after karyorrhexis, nucleus continues to degrade and basophilia fades. After 1 or 2 days, nucleus will complete disappear.
Name the 6 distinct patterns of necrosis.
- Coagulative necrosis: Firm texture for several days after tissue dies then WBC will phagocytize tissue and left will be a cavity or scar tissue (solid organs that experience severe ischemia- i.e. myocardial infarction)
- Liquefactive necrosis: When the CNS experiences ischemia (i.e. stroke)
- Gangrenous necrosis (ischemic necrosis): extremities experience coagulative necrosis (i.e. peripheral vascular disease, frostbite, major trauma that obstructs blood supply)
- Dry gangrene
- Wet gangrene: gangrenous tissue becomes infected with various bacteria and tissue liquefies
- Gas gangrene occurs when bacteria (clostridium perfringens) infects gangrenous tissue and gas byproducts become trapped within tissue.
Etiology
The cause, “risk factors”
Pathogenesis
sequence of events; describes the biological mechanisms that describe the structural and functional abnormalities of a disease process
