Cellular Responses to Stress, Injury, and Aging

Question 1

True or False

If a cell does not make adaptive changes as a result of stress, it will die.

Answer 1

True: adaptive changes allow the cell to survive and maintain some degree of function.

Question 2

What occurs for cells to adapt?

Answer 2

change in #, size, or type.

Question 3

What is atrophy?

Answer 3

a decrease in cell size. Occurs because of decrease of O2 consumption and organelle size.

Question 4

What are some causes of atrophy?

Answer 4

disuse, denervation, loss of endocrine stimulation, inadequate nutrition, ischaemia (decreased blood flow).

Question 5

What is hypertrophy?

Answer 5

increase in cell size and tissue mass. Occurs from normal physiological or abnormal pathologic.

Question 6

what kind of cellular response occurs in cells incapable of mitotic division?

Answer 6

hypertrophy

Question 7

What are causes of hypertrophy?

Answer 7

increased in workload: ATP depletion, increased membrane mechanical forces, or hormonal factors (IGF-1).

Question 8

What is necrosis?

Answer 8

unregulated cell and thus tissue death

Question 9

what results from an accumulation of bilirubin, usually due to liver disfunction?

Answer 9

jaundice

Question 10

what is metastatic calcification?

Answer 10

occurs when hypercalcemia causes calcium to accumulate in healthy tissues.

Question 11

What is autophagy?

Answer 11

The process whereby internal cell components are selectively destroyed through fusion with lysosomes.

Question 12

What is an increase in cell number?

Answer 12

hyperplasia

Question 13

What is ischemia?

Answer 13

a lack of blood flow to tissues that subsequently causes hypoxic tissue damage

Question 14

What is cell growth that is dysfunctional or deranged?

Answer 14

dysplasia

Question 15

What is metaplasia?

Answer 15

a reversible change of one cell type into another

Question 16

What is the name of programmed cell death?

Answer 16

apoptosis

Question 17

what cellular response is due to an increase in # of cells in an organ or tissue?

Answer 17

hyperplasia

Question 18

what does physiologic mean?

Answer 18

normal changes

Question 19

what does pathologic mean?

Answer 19

abnormal changes

Question 20

What are physiologic and pathologic changes that occur during hyperplasia?

Answer 20

physiologic- hormonal: breast/uterine enlargement during pregnancy
compensatory- liver regeneration after surgery

pathologic- hormonal: benign prostate hyperplasia
growth factor related- HPV skin warts.

Question 21

What is a reversible change cell response where one adult cell type is replaced by another?

Answer 21

metaplasia

Question 22

What are causes of metaplasia?

Answer 22

chronic inflammation/irritation such as smoking. cells can return to normal

Question 23

what is a deranged cell growth resulting in cells that vary in size, shape, and organization?

Answer 23

dysplasia

Question 24

What are examples of dysplasia?

Answer 24

HPV caused cervical or oropharyngeal cancer

Question 25

case study: a woman ruptured her left achilles tendon; 3 weeks later, you find: 1. left calf is smaller 2. circumference of right calf has increased 3. there are new callouses. Which cell and tissue adaptations occured?

Answer 25

1. atrophy 2. hypertrophy 3. hyperplasia

Question 26

which intracellular accumulations occur in stressed cells that are normal body substances?

Answer 26

lipids, proteins, and pigments.

Question 27

which intracellular accumulations of stressed cells are abnormal endogenous substances?

Answer 27

metabolic products- glycogen, lipds(NAFLD) - bilirubin retention (jaundice) -lipofuscin (wear-and-tear pigment)

Question 28

what are some intracellular accumulations in a stressed cell that are abnormal exogenous substances?

Answer 28

tattoo pigment, coal dust, lead poisoning

Question 29

What are the 2 types of pathological calcifications?

Answer 29

dystrophic calcification and metastatic calcification

Question 30

what calcification occurs in injured tissue in areas of necrosis? is it more local or systemic?

Answer 30

dystrophic; more local

Question 31

what is abnormal deposition of calcium salts in tissues?

Answer 31

calcification

Question 32

what usually occurs in normal tissues due to hypercalcemia? is it local or systemic

Answer 32

metastatic calcification; more systemic

Question 33

What are the types of cell injury?

Answer 33

physical, radiation, chemical, biologic agents, and nutritional imbalances

Question 34

True or False: If a cell is unable to maintain homeostasis in the face of injurious stimuli or stress, cells may not recover

Answer 34

false: cells may recover from certain types of damage or stress

Question 35

what are examples of physical cell injury

Answer 35

trauma, heat and cold, electricity

Question 36

what are examples of radiation cell injury?

Answer 36

ionizing, ultraviolet, nonionizing

Question 37

why is ionizing radiation generally more dangrous?

Answer 37

physically disrupts DNA in cells

Question 38

what are examples of chemical cell injury?

Answer 38

drugs, lead, mercury

Question 39

what are examples of biologic agents that cause cell injury?

Answer 39

bacteria, viruses, parasites

Question 40

what nutritional imbalances cause cell injury?

Answer 40

fats, minerals, vitamins and amino acids

Question 41

what are 3 types of cell injury mechanisms?

Answer 41

ROS, hypoxia/ischemia, increase in intracellular calcium

Question 42

what is hypoxia/ischemia?

Answer 42

when the cell is not provided with enough oxygen

Question 43

How do reactive oxygen species cause injury?

Answer 43

free radicals cause oxidation of cell structures and nuclear/mitochondrial DNA normal part of metabolism & intracellular signaling. antioxidants are defense mechanism

Question 44

how does hypoxia affect cells

Answer 44

aerobic metabolism stops and decreased ATP produced - Na/K ATPase decreases which increases intracellular Na which causes swelling with water - anaerobic metabolism used which decreases pH, this can lead to damaged cell membranes, intracellular structures and DNA - exposure to acute hypoxia linked to increase to hypoxia induced factors' (HIFs)

Question 45

how does impaired Ca2 homeostasis affect the cell?

Answer 45

disrupts Ca2/Mg2- atpase-dependent membrane pumps - excess Ca2 damages Ca2+ dependent phospholipases, proteases, ATPases & endonucleases

Question 46

excess calcium can lead to ?

Answer 46

Exercise induced muscle damage (EIMD) and DOMS

Question 47

What are the 3 outcomes of cell injury?

Answer 47

1. reversible injury, cell recovery, and return to normal function. 2. apoptosis and programmed cell removal 3. cell death and necrosis

Question 48

what is a normal & highly selective process that restructures tissues and replaces injured and aged cells?

Answer 48

apoptosis

Question 49

what are the two pathways of apopstosis?

Answer 49

extrinsic (death receptor respondent) intrinsic (death receptor independent)

Question 50

What enzyme is required for both pathways of apoptosis?

Answer 50

caspase

Question 51

what is autophagy?

Answer 51

internal cell components are engulfed and destroyed through fusion with lysosomes.

Question 52

What are inhibitors of apoptosis linked to?

Answer 52

cancer and autoimmune diseases

Question 53

what are senescent cells?

Answer 53

cells that are getting old and not working anymore

Question 54

what is the process of apoptosis?

Answer 54

1. shrinking of the cell 2-3. condensation and fragmentation of nuclear chromatin 4-5. separation of nuclear fragments and cytoplasmic organelles into apoptotic bodies 6. engulfment of fragments by phagocytic cells.

Question 55

what is necrotic cell death?

Answer 55

unregulated death caused by injuries to cells

Question 56

what occurs in necrotic cell death?

Answer 56

cells swell and rupture- lead to inflammation various forms occur: liquefaction, coagulation, caseous necrosis infarction- (tissue death) gangrene occurs when large mass of tissue undergoes necrosis

Question 57

why do cells change with aging?

Answer 57

programmed into cells because telomeres become to short; accumlated epigenetic changes to DNA; accumulated damage/error- DNA damage; oxidative free radical-mediated damage, glycation (AGE's cause tissue stiffening.)