cellular injury, adaptation, cell death

Question 1

is cellular injury only from a physical injury?

Answer 1

no! can occur in a variety of ways

Question 2

whenever there is injury.. there is some degree of cells that have…

Answer 2

lost function

injury—> loss of function

Question 3

extend of cell injury depends on? (4)

Answer 3

1. Cell type- major reason
   - epithelial is common in body and able to reproduce (skin), cells in heart do not repair as easily
2. Loss of perfusion (blood supply/flow to the tissues)
   - fluid moving to capillary beds, perfusion brings nutrients and O2 for ATP, healing and repair
3. Intensity
   - lower temp, greater injury/higher temp, greater injury
4. Duration
   - infection for 1 week vs 6months

Question 4

mechanisms of injury are? (3)

Answer 4

1. hypoxia
2. Ca+ imbalance
3. Free radicals

Question 5

explain hypoxia has a mechanism of injury

Answer 5

ATP production requires O2

• O2 deficiency= decreased ATP production, impairs cell function
• aerobic produces 36 ATP

Question 6

define: hypoxemia

Answer 6

deficiency of oxygen arterial blood

Question 7

explain ca+ imbalance as a mechanism of injury

Answer 7

too much or too little causes a problem

• Ca involved in many cellular function
• Injury–> Ca influx & release from organelles–> increased intracellular [Ca]–>enzymes activated–> cell damage

Question 8

explain free radicals as a mechanism of injury

Answer 8

small toxic chemical fragments

• unstable and reactive, unpredictable, interfere with other chemical reactions
• by products of other reactions, small quantity is okay, excess is detrimental
• bind to and affect DNA, proteins, and membranes

Question 9

what can cells adapt to?

Answer 9

• unfavorable conditions

- altered workload

Question 10

what is atrophy?

Answer 10

cells shrink, decrease in the mass of the tissue and level of function
-could be decrease in size of cells, or number of cells, or both

Question 11

what is hyperplasia?

Answer 11

increased number of cells and level of function

• increased tissue mass
• only will occur in tissues that replicate
• compensatory or pathologic

Question 12

what is hypertrophy?

Answer 12

increase in cell size and level of function

-enlarged tissue

Question 13

what is metaplasia?

Answer 13

transformation of 1 cell type into another

• tissue type that is now appearing at the site is not normal for that site
• normal for the body but NOT for the site
• generally occurs when that site is persistently exposed to some chronic irritation and inflammation

Question 14

what is dysplasia?

Answer 14

change in tissue where that tissue no longer contains normal cells

• abnormal cells now in tissue
• cells are changing in shape, size, organization
• pre cancerous? clinically very important, warning sign

Question 15

what is anaplasia?

Answer 15

abnormal differentiation and morphology

• change while the cells are forming
• the cells divide, then differentiate and take up shape of fully form nature, but in anaplasia the differentiation is not normal
• association with cancer?

Question 16

pathway from normal cells—> change in cell type

Answer 16

change in cell type—>metaplasia—>dysplasia

Question 17

pathway from normal cells—> change in cell size or number

Answer 17

change in cell size or number—> hyperplasia—> hypertrophy—> atrophy

Question 18

what is necrosis?

Answer 18

premature cell death

-abnormal

Question 19

what is apoptosis?

Answer 19

programmed cell death

• selective removal of aged and injured cells
• usually DNA regulates this, and usually a normal process