Exam 1: Altered Cellular Biology

Question 1

Define compensation:

Answer 1

Body’s attempt to maintain homeostasis under stress

Question 2

Define cell injury:

Answer 2

Result of stimulus *in excess* of cell’s adaptive response

Question 3

Types of cell injury:

Answer 3

Reversible and irreversible

Question 4

Describe reversible cell injury:

Answer 4

Causes cells to adapt for next time stress is applied True at the cellular level, but not at the tissue level

Question 5

Describe irreversible cell injury:

Answer 5

Cell death

Question 6

Tissues that hypertrophy/atrophy:

Answer 6

Cardiac Skeletal

Question 7

Tissues that become hyperplastic:

Answer 7

All beside cardiac/skeletal

Question 8

Describe metaplasia:

Answer 8

Change in type of cell present when current type is not adequate to deal with stress/irritant

Question 9

Examples of metaplasia:

Answer 9

• Barrett’s esophagus
• Cilia converting to stratified squamous in smokers

Question 10

Describe dysplasia:

Answer 10

Abnormal cells (not physiologically normal for any tissue)

Question 11

Describe neoplasia:

Answer 11

Abnormal cells lacking organization/structure

Question 12

What causes hypertrophy of the heart?

Answer 12

Hypertension Aortic stenosis Conditions that require more force to pump the same volume

Question 13

What type of athletes need hypertrophied hearts?

Answer 13

Power athletes - weightlifters, sprinters, rowers, etc Need high flow under high pressure

Question 14

Difference between hypertrophy in athletes and sick patients:

Answer 14

Sick patients: stress is 24/7, heart cannot rest and remodel properly Athletes: stress is transient, heart can rest and remodel in healthy way

Question 15

Is the metaplasia seen in smokers reversible?

Answer 15

Yes

Question 16

What parts of the brain form new cells regularly?

Answer 16

The hippocampus (memory center) and olfactory neurons

Question 17

What are four common themes in cell injury?

Answer 17

ATP depletion Free radicals/reactive oxygen species Increase in Ca++ in the cell Defects in the plasma membrane

Question 18

What does high Ca++ in the cell do?

Answer 18

Signals for it to die

Question 19

How is Ca++ removed from the cell?

Answer 19

ATP powered pump

Question 20

Embolus vs. thrombus:

Answer 20

Embolus: mobile, gets stuck Thrombus: occludes in situ

Question 21

Describe the chain of events that occurs within the ischemic cell:

Answer 21

Hypoxic mitochondria switch to anaerobic metabolism Low ATP signals cell to deplete glycogen in order to phosphorylate ADP Lactate production increases pH Acidic environment causes DNA clumping and lysosome swelling Lysosome rupture leads to autodigestion

Question 22

Describe the chain of events that occurs at the ischemic cell membrane:

Answer 22

Low ATP can’t pump out Na+ and Ca++, can’t return leaked K+ Osmotic effect means water trapped in cell (Ca++ leads to muscle contraction, using more ATP) Dilated ER can’t synthesize proteins Membrane becomes unrepaired and damaged More Ca++ in Cell contents out

Question 23

What are the clinical signs of cell damage?

Answer 23

Cytoplasmic proteins: troponin, CK, CK-MB, LDH

Question 24

Define hypoxia:

Answer 24

Low O2 in tissue

Question 25

Define hypoxemia:

Answer 25

Low blood O2

Question 26

Define ischemia:

Answer 26

Insufficient blood supply to tissue

Question 27

Define infarct:

Answer 27

Ischemia with necrosis

Question 28

What can cause localizes hypoxemia and hypoxia?

Answer 28

Embolus

Question 29

What can cause hypoxia without hypoxemia?

Answer 29

Anemia

Question 30

What causes reperfusion damage?

Answer 30

Production of reactive oxygen species

Question 31

How does the endogenous antioxidant system neutralize free radicals?

Answer 31

O2- converted to H2O2 by SOD; catalase converts H202 to H2O *or* glutathione converts H2O2 to H2O

Question 32

Why do frequent exercisers have so little risk of heart attack?

Answer 32

Cells adapt to the insult of free radicals produced during exercise

Question 33

How does necrosis affect neighboring cells?

Answer 33

Leakage of cell contents is signal for inflammatory process to clean up the mess

Question 34

How does apoptosis affect neighboring cells?

Answer 34

No cell content leakage into ECF; apoptotic bodies consumed by phagocytes without affecting rest of tissue

Question 35

Where does coagulative necrosis occur? What causes it? How does it happen?

Answer 35

Everywhere but the brain Caused by ischemia Cells die in place

Question 36

Where does liquefactive necrosis occur? What causes it? How does it happen?

Answer 36

In the brain Caused by ischemia Cells are obliterated by inflammation and enzymes dissolve them

Question 37

Where does caseous necrosis occur? What causes it? How does it happen?

Answer 37

In the lungs Caused by tuberculosis Cellular debris is cheese-like

Question 38

Where does fat necrosis occur? What causes it? How does it happen?

Answer 38

In the omentum/mesentery fat Pancreatic enzymes leak (pancreatitis) and saponify the abdominal fat

Question 39

Three types of gangrenous necrosis:

Answer 39

Dry Wet Gas

Question 40

Describe dry gangrene:

Answer 40

Typically diabetic in origin; neuropathy dulls warning pain Loss of blood flow means loss of immune response to infection

Question 41

Location of wet gangrene:

Answer 41

Internal organs or bedsores

Question 42

Cause of gas gangrene:

Answer 42

From c. perfringens

Question 43

What are telomeres?

Answer 43

6 nucleotide repeats on the end of chromosomes that limit number of replications

Question 44

What is replicative senescence?

Answer 44

When telomeres are exhausted and cells can no longer divide

Question 45

What opposes the natural shortening of telomeres?

Answer 45

Telomerase

Question 46

What cells normally have telomerase turned on?

Answer 46

Germ cells