Cell Injury, Adaption, and Death

Question 1

In what ways do cells adapt to chronic stress or insult?

Answer 1

hypertrophy
atrophy
hyperplasia
metaplasia
dysplasia

Question 2

When a myocyte hypertrophies, which components of the cell enlarge?

Answer 2

cytoplasm and nucleus

Question 3

When a bone is in a cast for weeks, in what ways do the cell adapt?

Answer 3

disuse atrophy –> decrease in cell size

Question 4

In Alzheimer’s disease, what kind of atrophy occurs?

What about if there is not enough ACTH produced by adrenal gland?

Answer 4

loss of cells
cerebral atrophy
in 80 y/o male, physiological atrophy
adrenal atrophy

Question 5

T/F: Atrophy can be loss of cells or decrease in cell size.

Answer 5

True

Question 6

What’s hyperplasia? Give an example. What’s the difference between hypertrophy and hyperplasia?

Answer 6

The increase in the number of cells - ex: endometrial hyperplasia; hyperplasia is increased number of cells, hypertrophy is enlarged cells

Question 7

Common from anovulatory cycles and unopposed estrogen, the stressor. Persistent uterine bleeding from endometrial breakdown can occur leading to anemia.

Answer 7

endometrial hyperplasia

Question 8

Idiopathic. Epidermal hyperplasia from chronic inflammation. Large skin plaques can result.

Answer 8

psoriasis: epidermal hyperplasia

Question 9

Increased # of cells from a persistent stress/stimulus

Answer 9

hyperplasia

Question 10

Explain an example of cigarette smoke involving metaplasia?

Answer 10

cigarette smoke irritates and causes normal ciliated columnar epithelium to become squamous cells

Question 11

When one cell type switches to another cell type, usually in response to an injurious process like cigarette smoke or acid reflux into the esophagus.

Answer 11

metaplasia

Question 12

Is metaplasia reversible? If it continues, what could happen?

Answer 12

Metaplasia is “usually” reversible if the noxious stressor is removed. If not, then it may go into dysplasia and dysplasia may lead to cancer.

Question 13

What can reflux from stomach to esophagus cause?

Answer 13

glandular metaplasia leading to glandular dysplasia - distal esophagus with squamous epithelium becomes glandular like that of the stomach

Question 14

How does a normal cell turn into a cancer cell? What is usually the cell stage before cancer?

Answer 14

Rarely does a normal cell directly turn into a cancer cell. It will become a hyperplastic or metaplastic cell, a dysplastic cell, and then cancer. The stage before cancer is dysplasia.

Question 15

If a thrombus causes a vasospasm, what type of necrosis results?

Answer 15

ischemic necrosis (coagulative)

Question 16

An infarct is an area of (blank)

Answer 16

necrosis

Question 17

What’s the difference between necrosis and apoptosis?

Answer 17

necrosis = accidental cell death
apoptosis = programmed cell death

Question 18

When there is ischemia, or sudden loss of blood flow, what does this affect on the cellular level? What three things increase inside the cell during cell swelling?

Answer 18

halts ATP production
affects ion channels and ion pumps
Na+, Ca+, lactic acid

Question 19

Following an injury, what happens initially? Then, biochemical, ultrastructural, light microscopic changes, and gross morphologic changes occur over time.

Answer 19

loss of cell function

Question 20

Necrosis caused by occlusion of vascular supply

Answer 20

coagulative necrosis

Question 21

This type of necrosis is seen in the brain and in infections

Answer 21

liquefactive necrosis

Question 22

This type of necrosis is seen in tuberculosis - it looks cheesy

Answer 22

caseous necrosis

Question 23

This type of necrosis is seen in syphilis

Answer 23

gummatous necrosis

Question 24

This type of necrosis is seen in vessel walls in hypertension and vasculitis

Answer 24

fibrinoid necrosis

Question 25

What does Ca++ do to mitochondria?

Answer 25

poisons it

Question 26

What is MPT?

Answer 26

mitochondrial permeability transition - it is when pores develop in response to too much Ca++ - causes H+ to flow out and leads to loss of membrane potential and inability to generate ATP

Question 27

What are ROSs? What percentage of molecular oxygen consumed in the mito is converted to ROS?

Answer 27

reactive oxygen species; 5%

Question 28

List some reactive oxygen species generated normally

Answer 28

O2- (superoxide)
H2O2
OH-

Question 29

What is oxidative stress?

Answer 29

when reactive oxygen species overwhelms antioxidants

Question 30

What do ROS lead to?

Answer 30

lipid peroxidation ultimately leading to membrane damage

Question 31

Following an infarct, what is the area of savable cells called?

Answer 31

ischemic penumbra

Question 32

When you draw blood, you are looking for enzymes. How are enzymes getting into the blood?

Answer 32

ROS causing lipid peroxidation –> membrane damage –> enzymes leaking into blood

Question 33

What happens to myocardial ischemia with reperfusion (breaking up thrombi)? Does it cause injury? Why is this ok?

Answer 33

allows for smaller final infarct size, but there is still reperfusion injury. This is ok, because it causes more good than harm.

Question 34

What happens when you reoxygenate cells?

Answer 34

reperfusion injury caused by free radicals - mitochondrial perfusion transition

Question 35

What causes reperfusion injury?

Answer 35

oxygen free radicals

Ca++ overload

Question 36

Two forms of apoptosis?

Answer 36

intrinsic

extrinsic

Question 37

During the mitochondrial instrinsic pathway, what happens when you dump cyto C from mito into cell?

Answer 37

start releasing caspases

Question 38

What is the extrinsic (death receptor) pathway?

Answer 38

cytotoxic T cell comes along and binds to TNF receptor and induced cell death

Question 39

What is TNF?

Answer 39

a cytokine

Question 40

Fas binds to FasL and activates the death domain. What pathway is this?

Answer 40

extrinsic pathway

Question 41

With viral hepatitis, what type of cell death occurs? How?

Answer 41

apoptosis - hepatocytes express HLA1. Cytotoxic T cell with FasL recognizes this ligand, causes caspase 8 activation and initiates a caspase cascade

Question 42

What does too much alcohol cause in hepatocytes?

Answer 42

too much fat in hepatocytes – fatty liver