CELL INJURY, ADAPTATIONS AND DEATH - 1

Question 1

List instances of atrophy occuring due to loss of endocrine stimulation

Answer 1

i. Atrophy of the endometrium, vaginal epithelium, and breast following loss of estrogen stimulation as in menopause
ii. Hypopituitarism - atrophy of target organs, such as the thyroid and adrenal cortex; Sheehan Syndrome

Question 2

1. Identify the pattern of cell adaptation described below.

Change from columnar to squamous epithelium in the respiratory tract in response to chronic irritation from cigarette smoke

2. List 3 other examples for the same

Answer 2

1. Squamous metaplasia
2. Other examples of squamous metaplasia are:
   a. Stones in the excretory ducts of the salivary glands, pancreas, or bile ducts
   b. deficiency of vitamin A (retinoic acid) induces squamous metaplasia in the respiratory epithelium
   c. Mucus-secreting endocervical cells (ECCs) encountering the acid pH of the vagina undergo squamous metaplasia

Question 3

Identify the pattern of hypertrophy described:

1. New sarcomeres are predominantly assembled in parallel to the long axes of cells
2. Myocytes thicken
3. •Wall thickness increases without proportional chamber dilatation

Answer 3

Concentric hypertrophy

Question 4

List 1 word that best describes the following

•reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type

Answer 4

Metaplasia

Question 5

Identify the molecular mechanisms repsonsible for the adaptation seen in the attached image.

Answer 5

In this case of Alzheimer’s disease, there is more marked atrophy seen superiorly and laterally, with sparing of the occipital region.

The mechanism is:

1. Decrease in cell number through apoptosis
2. Decrease in cell size through increased degradation of proteins via the ubiquitin-proteasome pathway and consumption of cell organelles through autophagy

Question 6

Given the clinical scenario below, identify the molecular mechanism responsible for the cell adaptation described

Transformation of pseudostratified ciliated columnar epithelium to squamous epithelium in the respiratory tract in an individual deficient in Vitamin A

Answer 6

reprogramming of stem cells

Question 7

List 1 word that best describes the following:

An increase in the number of cells in an organ or tissue in response to a stimulus

Answer 7

Hyperplasia

Question 8

Identify the molecular mechanisms repsonsible for the adaptation seen in the attached image.

Answer 8

1. Increased production of cellular proteins.
2. switch of contractile proteins from adult to fetal or neonatal forms

Question 9

Identify the pattern of cell adaptation shown in the attached image.

Answer 9

Dysplasia

Question 10

List 3 microscopic features of dysplasia

Answer 10

a. Disorderly proliferation of cells occurs with loss of cell maturation as the cells progress to the surface
b. ↑mitotic activity (normal spindles)
c. ↑nuclear size/chromatin

Question 11

1. Identify the finding shown in the attached image
2. What is the most likely etiology?

Answer 11

1. Red neurons
2. Hypoxia

Question 12

Portions of the kidney that are at most risk for ischemic damage

Answer 12

early proximal tubule and the thick ascending limb of the loop of Henle

Question 13

How is superoxide inactivated?

Answer 13

Superoxide dismutase which converts it to H₂O₂ and O₂

Question 14

List 1 word that describes the following:

•an increase in the size of cells, that results in an increase in the size of the affected organ

Answer 14

Hypertrophy

Question 15

List 1 word that means the following:

‘steady state’

Answer 15

Homeostasis

Question 16

What pattern of cell adaptation would occur in a patient with chronic hemodynamic overload due to hypertension or faulty valves?

Answer 16

Hypertrophy

Question 17

3 mechanisms via which free radicals cause damage

Answer 17

a. Lipid peroxidation in membranes
b. Oxidative modification of proteins
c. Lesions in DNA

Question 18

Which is more dangerous, Ischemia or hypoxia in the absence of ischemia?

Answer 18

Ischemia

Question 19

What is the mechanism of mucus gland hyperplasia in smokers?

Answer 19

Chronic irritation

Question 20

Identify the pattern of cell adaptation likely to have occured in the scenario described below

bone formation in muscle after intramuscular hemorrhage

Answer 20

The scenario is myositis ossificans. The cell adaptation is connective tissue metaplasia

Question 21

See the attached image.

1. Identify the pigment accumulated within cells.
2. What cell eating process is this pigment associated with?

Answer 21

1. Lipofuscin

2. Autophagy

Note: Increased autophagy is seen in severe atrophy. Lipofuscin granules represent the residual bodies that accumulate as a result of autophagy. Excessive accumulation imparts a brown color to tissue. In the setting of atrophy, it is called brown atrophy – common age-related finding.

Refer Slide 18 of the ppt

Question 22

Identify the molecular mechanisms repsonsible for the adaptation seen in the attached photmicrograph of the prostate.

Answer 22

increased output of new cells from tissue stem cells

Question 23

1. What would be the clinical consequence of ischemia in the splenic flexure area?
2. List the 2 vessels supplying this area.

Answer 23

1. Ischemic colitis
2. SMA and IMA

Question 24

The attached image is a section of the pancreas in a patient with cystic fibrosis.

1. Identify the cellular adaptation likely to have occured.

2. What is the mechanism?

Answer 24

1. Pathologic atrophy
2. Increased pressure due to thick duct secretions—> atrophy of exocrine glands in Cystic Fibrosis

Question 25

List the 6 mechanisms of pathologic atrophy

Answer 25

Decreased workload (atrophy of disuse)

Loss of innervation (denervation atrophy)

Diminished blood supply

Inadequate nutrition

Loss of endocrine stimulation

Increased pressure

Question 26

First visible sign of tissue hypoxia detected by the light microscope

Answer 26

Cellular swelling/Hydropic change

Question 27

Pattern of hypertrophy likley to be encountered in chronic mitral or aortic regurgitation

Answer 27

Eccentric Hypertrophy

Question 28

List 2 examples of physiologic hypertrophy

Answer 28

a. increased functional demand - Skeletal muscle weight training
b. massive physiologic growth of the uterus during pregnancy

Question 29

What term best defines the description below?

Loss of cells in addition to the cells that are irreversibly damaged at the end of ischemia, following restoration of blood flow

Answer 29

Ischemia-Reperfusion Injury

Question 30

Identify the finding shown in the image below

What is the mechanism?

Answer 30

1. Hydropic change
2. Failure of energy-dependent ion pumps in the plasma membrane

Question 31

List 1 word that describes the following:

reversible functional and structural re­sponses to changes in physiologic states and some pathologic stimuli, during which new but altered steady states are achieved

Answer 31

Adaptations

Question 32

List one word that means the following:

reduction in the size of an organ or tissue due to a decrease in cell size and number.

Answer 32

Atrophy

Question 33

1. See attached image of an endometrial biopsy specimen and identify the type of cell adaptation seen.
2. List one other pathologic condition** where the same type of cell adaptation is encountered **due to the same mechanism

Answer 33

1. Endometrial hyperplasia
2. Benign prostatic hyperplasia

Question 34

List 1 word that best describes the following:

reduction in the size of an organ or tissue due to a decrease in cell size and number.

Answer 34

Atrophy

Question 35

Consequences of membrane damage to the following:

a. Mitochondria
b. Plasma membrane
c. Lysosomes

Answer 35

a. Apoptotic death
b. cell swelling, leakage of cell contents
c. enzymatic digestion of proteins, RNA, DNA, and glycogen

Question 36

2 consistent features of irreversibility of cell injury

Answer 36

a. Inability to reverse mitochondrial dysfunction (lack of oxidative phosphorylation and ATP generation)
b. Profound disturbances in membrane function

Question 37

The zone of hepatocytes most susceptible to hypoxia.

Why?

Answer 37

Zone III

Zone III hepatocytes constitute the zone that is located farthest from the portal triad and receives the least amount of oxygen and nutrients.

Question 38

List the 4 mechanisms of ischemic-reperfusion injury

Answer 38

1. Oxidative stress
2. Intracellular calcium overload
3. Inflammation
4. Activation of the complement system

Question 39

List one term that best fits the description given below:

a. excess of oxygen derived free radicals
b. chemical species that have a single unpaired electron in an outer orbit.

Answer 39

a. Oxidative stress
b. Free radicals

Question 40

List 2 examples of physiologic atrophy

Answer 40

During fetal development- notochord and thyroglossal duct regression

Decrease in the size of the uterus that occurs shortly after parturition

Question 41

What cell adaptation is likely to have occured in the attached image?

Answer 41

Columnar metaplasia

Question 42

1 example of metaplasia that is NOT associated with an increased risk of cancer

Answer 42

Apocrine metaplasia in the breast