Chapter 4: Cell Injury, Aging, And Death

Question 1

Ischemia

Answer 1

most common cause of cell injury and injures cell faster than hypoxia alone

Question 2

Hypoxia

Answer 2

causes power failure in the cell which is also caused by ischemia

Question 3

Lactic Acidosis in Ishcemia

Answer 3

Cellular proteins and enzymes become more dysfunctional

Question 4

When does cell death occur?

Answer 4

When plasma, mitochondrial, and lysosomal membranes are critically damaged

Question 5

Hydropic Swelling

Answer 5

Cellular swelling due to accumulation of water

Question 6

Why does hydropic swelling occur?

Answer 6

Malfunction of sodium-potassium pump with accumulation of sodium ions within the cell and also any injury that results in loss of energy(ATP).

Question 7

What does cellular swelling look like?

Answer 7

Large, pale cytoplasm, dilated endoplasmic reticulum, and swollen mitochondria

Question 8

Intracellular Accumulations

Answer 8

Accumulation of excessive amounts of normal intracellular substance, abnormal substances from faulty metabolism, and pigments or particles that the cell is unable to degrade

Question 9

What are the nutritional injuries?

Answer 9

Nutritional deficiency and Nutritional Excesses

Question 10

Nutritional Deficiency results from?

Answer 10

Poor intake, altered absorption, impaired distribution by circulatory system, and inefficient cellular uptake

Question 11

Nutritional Excesses results from?

Answer 11

Excessive intake, BMI greater than 27kg/m^2 which can be considered a health risk or even obesity

Question 12

Chemical Injury

Answer 12

Toxic chemicals or poisons can cause cellular injury both directly and by becoming metabolized into reactive chemicals by the body

Question 13

What are the factors of physical and mechanical injury?

Answer 13

Extreme temperatures, abrupt changes in atmospheric pressure, mechanical deformation, electricity, and ionizing radiation.

Question 14

Atrophy

Answer 14

Cells shrink and reduce their differentiated functions in response to normal and injurious factors

Question 15

Causes of Atrophy

Answer 15

Disuse, denervation, ishcemia, nutrient starvation, interruption of endocrine signals, and persistent cell injury

Question 16

Hypertrophy

Answer 16

Increase in cell mass accompanied by an augmented functional capacity in response to physiologic and pathophysiologic demands and caused by increased cellular protein content

Question 17

Hyperplasia

Answer 17

Increase in cell number due to mitotic division

Question 18

Causes of hyperplasia

Answer 18

Response to increased physiologic demands or hormonal stimulation and also due to persistent cell injury, chronic irritation of epithelial cells

Question 19

Metaplasia

Answer 19

Replacement of one differentiated cell type with another

Question 20

Causes of Metaplasia

Answer 20

Adaptation to persistent injury, with replacement of a cell type that is better suited to tolerate injurious stimulation. It’s also fully reversible when injurious stimulation is removed.

Question 21

Dysplasia

Answer 21

disorganized appearance of cells because of abnormal variations in size, shape, and arrangement. It also gives a potential to transform into cancerous cells(pre-neoplastic lesions)

Question 22

Necrosis

Answer 22

Consequence of ischemia or toxic injury or other injuries and is characterized by cell rupture, spilling of contents into extracellular fluid, and inflammation

Question 23

What are the four types of tissue necrosis?

Answer 23

Coagulative, Liquefactive, Fat Necrosis, and Caseous Necrosis

Question 24

Coagulative Necrosis (Heart)

Answer 24

Begins with ischemia and ends with degradation of plasma membrane

Question 25

Liquefactive Necrosis (Brain)

Answer 25

Occurs with dissolution of dead cells. Liquification of lysosomal enzymes happens. Formation of abscess or cyst from dissolved dead tissue.

Question 26

Fat Necrosis (Pancreas)

Answer 26

Death of adipose tissue. Results from trauma or pancreatitis. Appears as a chalky white area of tissue.

Question 27

Caseous Necrosis (Lung)

Answer 27

Characteristic of lung damage secondary to tuberculosis and it also resembles clumpy cheese

Question 28

Gangrene

Answer 28

Cellular death in a large area of tissue

Question 29

Dry Gangrene

Answer 29

A form of coagulative necrosis and is charactized by blackened, dry, wrinkled tissue, separated by a line of demarcation from healthy tissue

Question 30

Wet Gangrene

Answer 30

A form of liquefactive necrosis. Typically found in internal organs and can be fatal.

Question 31

Gas Gangrene

Answer 31

Results from infection of necrotic issue by anaerobic bacteria(Clostridium diff). Characterized by formation of gas bubbles in damaged muscle tissue and it can be fatal.

Question 32

Apoptosis

Answer 32

Occurs in response to injury that does not directly kill the cell. It triggers intracellular cascades and activates a cellular suicide response. It does not cause inflammation.

Question 33

How can intrinsic pathways trigger apoptosis?

Answer 33

In response to severe cell damage, a protein will increase in response to cellular DNA damage, triggering the cell’s own death. It also involves many intracellular signals and enzymes.

Question 34

What are the mechanisms of Radiation injury?

Answer 34

Heat, radiolysis which leads to apoptosis, and free radicals

Question 35

What are the cellular basis of aging?

Answer 35

Cumulative result from two factors cause cellular and molecular damage which are: progressive decline in proliferation and reparative capacity of cells, inability to adapt to environmental demand, and exposure to environmental factors.

Question 36

Somatic Death

Answer 36

Death of the entire organism. No inflammation or immunologic response occurs prior to death.

Question 37

What happens during Somatic Death?

Answer 37

Cessation of respirations and heartbeat. Presence of stiffened muscles throughout the body after death which is rigor mortis, then flaccid. Release of lytic enzymes in body tissue which is postmortem autolysis. Determination of “brain death” as proof of somatic death.