Test 2 Flashcards
(140 cards)
ischemia
loss of blood to an area
Hypoxia
oxygen deprivation
how does hypoxia cause cellular injury?
Oxygen is the final electron acceptor in the electron transport chain which makes ATP, without the final electron acceptor, the cell cannot make enough ATP
What are the 7 causes of cellular injury?
toxins, foreign invaders, immunological reactions, genetic defects, nutritional balances, physical agents, aging
how do toxins cause cellular injury?
impede enzymes, affect membranes and metabolism
how do foreign invaders cause cellular injury?
they can produce toxins, or disrupt cellular function on their own
how do immunological reactions cause cell injury?
through responses to foreign invaders and through autoimmune diseases
how do genetic defects cause cell injury?
mistakes in DNA code for the wrong proteins and the wrong proteins are produced
how does aging cause cell injury?
alters ability to replicate, divide, or repair
what two things can cause an irreversible cell injury?
inability to disrupt mitochondrial function, and disruption of the cellular membrane
progression in how tissues respond to injury
Cellular Swelling, Hydropic Degeneration, Lipid Degeneration, Necrosis
what occurs during cellular swelling and why?
Na/K pumps need ATP to work. When they don’t work, Na accumulates inside the cell, and due to osmosis, water follows and also accumulates inside the cell. Reversible
what occurs during hydropic degeneration and why?
Cells need to do something with excess water inside the cell, so they channel the water to the smooth ER which puts them in vacuoles that detach from the smooth ER
vacuolization
vacuoles fill the cell and push organelles to the side
what happens during lipid degeneration and why?
Smooth ER is dealing with excess water and loses it’s primary function - lipid metabolism. lipid accumulates in the vacuoles with the water. All organelles are pushed to the sides and the vacuole resembles a mature adipocyte
necrosis
abnormal cell death that occurs with disease or injury - irreversible
What are the steps to necrosis?
pyknosis, dissolution of the plasma membrane, karyosis
condensation of nuclear material into a tight, dense spot
pyknosis
what is the problem with dissolution of the plasma membrane?
internal and external parts of the cell mix and cellular contents are released
occurs when the nuclear membrane breaks down and all that is left of the cell is fragments
karyosis
what does the fate of necrotic tissue depend upon?
the number of cells involved and the types of cells
what are the 5 fates of necrotic tissue?
phagocytosis, slough it off, scar it over, encapsulate it in connective tissue, or calcify it
what is the most popular way that the body deals with things it can’t get rid of?
calcification
how does calcification occur in the body?
change the pH in an area, calcium precipitates out and a calcium wall is formed