Exam 1 (Lecture 2) - Cell Injury

Question 1

What are cell membranes?

Answer 1

Fluidic phospholipid bilayers that enclose cells and their organelles.

Question 2

What are the two major functions of cell membranes?

Answer 2

1) Serve as selective barriers

2) Form a structural base for the membrane-associated proteins (enzymes and receptors) that determine cell function

Question 3

What does the term fluidic mean?

Answer 3

This means that the proteins and lipids in the membrane are not immoveable but can travel throughout the cell.

Question 4

What is the importance of the plasma membrane?

Answer 4

The plasma membrane is the first contact with harmful substances such as toxins or infectious microbes.

Question 5

What is the major function of mitochondria?

Answer 5

The generation of energy (ATP). (They HAVE to have O2)!!

Question 6

What is the function of the rough ER?

Answer 6

Proteins are made there; they go into membranes or outside of cell.

Question 7

What is the function of smooth ER?

Answer 7

Production of FAs and cholesterol.

Question 8

What is contained in the nucleus?

Answer 8

Chromatin (DNA and proteins)

Question 9

What is the function of the nucleolus?

Answer 9

The production of ribosomes/RNA.

Question 10

What type of filament is actin?

Answer 10

Microfilament

Question 11

What is the function of intermediate filaments?

Answer 11

Anchors the cell

Question 11

What do microtubules do?

Answer 11

They’re the “highways” of the cell

Question 12

What are the two broad causes of cell injury? Give examples of each.

Answer 12

1) Extrinsic: bacteria, viruses, toxins

2) Intrinsic: cell machinery not working correctly

Question 13

Does the cell have an abundance of ways to respond to injury?

Answer 13

No; limited ways to respond to injury.

Question 14

What are the fundamental mechanisms of cell injury?

Answer 14

1) ATP depletion

2) Permeabilization of cell membranes

3) Disruption of biochemical pathways

4) Damage to DNA: Can’t produce RNA = problems downstream (can’t make proteins)

Question 15

What are the cellular responses to stress?

Answer 15

1) Adapt: (Increase in cell number, increase in cell size, alter structure)

2) Be reversibly injured: (Increased water, increased lipids)

3) Die: (Necrosis: not programmed; Apoptosis: programmed)

Question 16

What are the causes of cell injury?

Answer 16

1) Oxygen deficiency
2) Physical agents
3) Infectious agents
4) Nutritional deficiency/imbalance
5) Genetic derangement
6) Workload imbalance
7) Chemicals/Drugs/Toxins
8) Immunologic dysfunction
9) Aging

Question 17

What is an example of oxygen deficiency?

Answer 17

Hypoxia (cell won’t be able to produce enough ATP/energy)

Question 18

What are examples of physical agents?

Answer 18

Heat, cold, radiation, toxins, trauma

Question 19

What are examples of infectious agents?

Answer 19

Bacteria, viruses, parasites, prions

Question 20

What are examples of nutritional deficiencies/imbalances?

Answer 20

Protein deficiency, vitamin/mineral deficiency

Question 21

What are examples of genetic derangement?

Answer 21

Inherited, acquired

Question 22

What is an example of a workload imbalance?

Answer 22

Too much, too little work

Question 23

What are the causes of hypoxia?

Answer 23

1) Ischemia (decreased blood flow)

2) Anemia (decreased RBC, Hb)

3) Carbon monoxide (decreased O2)

4) Respiratory failure: asphyxia (decreased gas exchange)

5) Cardiac failure (decreased cardiac output)

6) Thrombus, trauma

Question 24

What are the steps of acute cell swelling?

***In cell swelling, cytoplasm will appear pale due to increased water

Answer 24

Injury –> hypoxia –> ATP production decreases –> Na+ and water move into cell, K+ moves out –> osmotic pressure increases –> more water moves into cell –> cisternae of ER distend, rupture, and form vacuoles –> extensive vacuolation –> hydropic degeneration (acute cell swelling in liver/kidneys)

Question 25

What is ballooning degeneration?

Answer 25

Acute cell swelling in epithelial cells (skin)

Question 26

What is cytotoxic degeneration?

Answer 26

Acute cell swelling in neurons

Question 27

Is cell swelling reversible?

Answer 27

To a point; until there is mitochondrial and/or cell membrane damage

Question 28

What are the 3 forms of cell death?

Answer 28

1) Necrosis

2) Apoptosis

3) Post-mortem autolysis

Question 29

How does cell swelling occur?

Answer 29

Hypoxia –> decreased ATP

Membrane injury –> loss of environmental control