Cell Injury 1 and 2

Question 1

cell injury is defined as a ____

Answer 1

disturbance in homeostasis

Question 2

consequences of cell death depend on:

Answer 2

the type of insult, the duration, the severity, and the type of cell

Question 3

what are the two ways you can “die” at the top of the mountain? AKA, what are the two mechanisms of cell death?

Answer 3

dramatic death, necrosis

quiet death, apoptosis

Question 4

what are the 3 categories of the causes of cell injury?

Answer 4

extrinsic (trauma, infection, toxins, etc)

intrinsic (genetics)

combined (nutritional imbalances, workload imbalances, immunological issues, etc(

Question 5

the most common and important cause of cell injury and death is ____

Answer 5

oxygen deficiency

Question 6

difference between hypoxia and anoxia?

Answer 6

hypoxia: partial reduction in O2 supply
anoxia: complete deprivation of oxygen supply

Question 7

which cell types are the most sensitive to low oxygen content?

Answer 7

neurons>cardiac myocytes, hepatocytes, and renal epithelium> CT, skeletal muscle

Question 8

what are the 3 categories of causes of hypoxia?

Answer 8

inadequate intake

blood vessel obstruction

inability to use oxygen

Question 9

when it comes to the immune system, what are the 3 ways in which cell injury or death can occur

Answer 9

immunodeficiency (immune system damaged or not working)

allergic or hypersensitivity (over reaction)

autoimmune (attacking self)

Question 10

what are the 2 most common causes of cell injury in general?

Answer 10

ATP depletion

cell membrane damage

Question 11

cell injury is considered reversible if _____

Answer 11

the injured cell can regain homeostasis and return to a normal functional state

Question 12

what is the classic morphological change in reversible cell injury called? What is important to remember about this term?

Answer 12

acute cell swelling

this is also indicative of early irreversible damage so it is best to think of acute cell swelling as potentially reversible

Question 13

acute cell swelling indicates _______

Answer 13

loss of cell volume control (ATP depletion or cell membrane damage)

Question 14

what 2 functions does the cell membrane serve?

Answer 14

it is a selectively permeable barrier, and it contains ATP dependent ion pumps

Question 15

explain how hypoxic injury can lead to acute cell swelling

Answer 15

low oxygen leads to low ATP. this causes the ion pumps to fail and sodium moves into the cell. water follows, the cell swells up, the organelles fill with water, leading to extensive vacuolation

Question 16

explain how membrane damage can cause acute cell swelling

Answer 16

the damage allows sodium to move into the cells, water follows, cell swells, water gets into organelles, extensive vacuolation

Question 17

what is the main cause of cell membrane injury ?

Answer 17

free radicals

Question 18

where do free radicals come from?

Answer 18

normal oxidative phosphorylation, exposure to certain toxins, radiation, or drugs, inflammation, and ischemia-reperfusion injury (if blood supply is cut off and there is regeneration, free radicals are formed)

Question 19

how do free radicals injure a cell?

Answer 19

via lipid peroxidation of the cell membrane (free radicals steal electrons from the lipids in cell membranes)

Question 20

how does the body naturally combat free radicals?

Answer 20

vitamins A, C,E

enzymes

binding proteins using iron or copper

Question 21

what is white muscle disease caused by?

Answer 21

free radicals injure the cell membranes and the cell death leads to mineralization in the muscle, making it appear white and chalky

Question 22

how can we as pathologists identify cell injury?

Answer 22

blood chemistry, microscopic changes, gross changes (can be seen with naked eye)

if the death is sudden there may not be visible change

Question 23

how are organs with acute cell swelling different than normal organs?

Answer 23

they weigh more than normal, they are pale, swollen, and tissues may bulge

Question 24

how is acute cell swelling identified under a microscope?

Answer 24

hydropic degeneration and cloudy swelling. the cells appear swollen and are paler in color, the cytoplasm is vacuolated

Question 25

what is ballooning degeneration?

Answer 25

extreme variant of hydropic degeneration commonly seen in the keratinocytes of the stratified squamous epithelium