2Cellular Adaptation and Cell Necrosis

Question 1

Define Cell Adaptation

Answer 1

Prolonged exposure of cells to adverse or exaggerated normal stimuli which evokes various changes at the level of individual cells, tissues or whole organs. Once cause is removed most cells return to normal when they don’t(anaplasia: cancer)

Question 2

How do cells adapt to change?

Answer 2

1. atrophy
2. hypertrophy
3. hyperplasia
4. metaplasia
5. dysplasia
6. anaplasia

1-3 pathologic and physiologic
4-6 always pathologic

Question 3

Define Atrophy

Answer 3

Decrease in the size of a tissue, organ or the entire body.

2 kinds: Physiologic and pathologic

Question 4

Physiologic Atrophy examples

Answer 4

Thymus undergoing involution
Ovaries, uterus and breasts after menopause
Bones in elderly become thin and prone to fracture

Question 5

Define Involution

Answer 5

the shrinkage of an organ in old age or when inactive, e.g., of the uterus after childbirth

Question 6

Pathologic Atrophy examples

Answer 6

Ischemic organs are typically small ie: kidneys involved with atherosclerosis
Testicular atrophy
Alzheimer Dementia: shrinkage of brain best example of Pathologic atrophy

Question 7

Define Atherosclerosis

Answer 7

a disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls.

Question 8

Define Hypertrophy

Answer 8

An increase in the size of tissue or organs due to enlargement of individual cells

Question 9

Examples of physiologic hypertrophy

Answer 9

Enlargement of skeletal muscles in body builders due to weights

Question 10

Examples of pathologic hypertophy

Answer 10

hypertrophy of the heart occurs as an adaptation to increased workload
Concentric hypertrophy of the left ventricular muscle is typically seen in hypertension(along with overall enlargement) an adaptive response to left ventricular pressure overload

Question 11

Cardiomegaly vs Cardiomyopathy

Answer 11

Cardiomyopathy is genetic

Cardiomegaly is not genetic

Question 12

Define hyperplasia

Answer 12

An adaptive increase in the number of cells that can cause enlargement of tissues or organs

Question 13

Examples of hyperplasia processes and disease states where it is seen

Answer 13

Endometrial hyperplasia due to estrogens
Hyperplastic polyps of the colon or stomach
Endometrial Hyperplasia: pathologic

Question 14

Can hyperplasia and hypertrophy be seen together?

Answer 14

Yes

Question 15

hyperplasia with hypertrophy examples

Answer 15

Physiologic hypertrophy of the uterine smooth muscle cells during pregnancy is also accompanied by hyperplasia 
Hyperplastic prostate(BPH) increases both the size and number of glands and stroma

Question 16

Define metaplasia

Answer 16

An adaptive change of one cell type for another to suit the environment

Question 17

Examples of metaplasia

Answer 17

Squamous metaplasia of the bronchial epithelium due to smoking
Gastric or glandular metaplasia of GE Junction in Barrett Esophagus

Question 18

Is metaplasia reversible?

Can it progress to a more detrimental growth?

Answer 18

yes

Yes. it may progress to Dysplasia

Question 19

Define dysplasia

Answer 19

Disordered growth of tissues resulting from chronic irritation or infection
Precancerous condition

Question 20

Best example of dysplasia related to a disease

Answer 20

PAP smears detect cervical dysplasia
(Cervical intraepithelial neoplasia or CIN)
mild moderate and severe forms

Question 21

Define Anaplasia

Answer 21

Undifferentiated and uncontrolled growth cells- the hallmark of malignant transformation

Question 22

Anaplasia AKA

Answer 22

Malignancy
Carcinoma
Cancer
Neoplasm

Question 23

Examples of Anaplasia

Answer 23

Squamous cell carcinoma of the cervix
Cancer of the lung
Malignant melanoma
Renal cell carcinoma

Question 24

Microscopic hallmarks of Anaplasia

Answer 24

1. cells and nuclei display marked cellular pleomorphism(variation in size and shape)
2. nuclei are irregular and hyperchromatic
3. extremely high nuclear/cytoplasmic ratio(N/C ratio) about 1:1 instead of 1:4 or 1:6
4. large nucleoli present within nucleus
5. large numbers of abnormal mitotic figures

Question 25

define necrosis

Answer 25

the death of cells or groups of cells(tissues) within a living organism

Question 26

Necrosis vs autolysis

Answer 26

necrosis is seen in the living (with inflammation) and autolysis is seen in tissues after death

Question 27

Types of necrosis

Answer 27

Coagulative
Liquefactive
Caseous
Fat

Question 28

Define Coagulative Necrosis

Answer 28

The most common form of necrosis. Occurs when cell proteins are altered or denatured, similar to the coagulation that occurs when cooking eggs. Histologically, the cell outlines are preserved and cytoplasm appears finely granular

Question 29

cause and examples of Coagulative Necrosis

Answer 29

typically occurs in solid internal organs: kindey, heart,spleen and liver
Most often caused by anoxia
Ex: heart tissue undergoing a myocardial infarction

Question 30

Define Liquefactive necrosis

Answer 30

a process by which dead cells liquefy under the influence of certain cell enzymes. the tissue becomes soft and gel like

Question 31

examples of liquefactive necrosis

Answer 31

occurs most often in the brain where the brain cells lose their contours and liquefy. this necrosis is typical of brain infarcts which are usually soft and are ultimately transformed into fluid-filled cavity, or can be seen in certain bacterial infections in which a cavity may develop(abscesses in the lungs)

Question 32

What is the most common cause of abscesses?

Answer 32

Gram positive cocci in grape like clusters: staph aureus

Question 33

Define Caseous necrosis

Answer 33

A form of coagulative necrosis in which thick, yellowish, cheesy substance forms

Question 34

Examples and characteristics of caseous necrosis

Answer 34

Typically found in TB, characterized by development of lung granulomas, inside of which can be found caseous necrosis. This is called a Ghon complx and usually heals, containing the infection. Not unique to TB may be seen in some fungal infections: Histoplasmosis

Question 35

Define fat necrosis

Answer 35

a specialized form of liquefaction necrosis caused by the action of lipolytic enzymes

Question 36

Examples and characteristics of fat necrosis

Answer 36

limited to fat tissue usually around the pancreas, where enzymes are released into the adjacent fat tissue, usually after rupture of the pancreas(trauma, acute pancreatitis), causing degradation of fat into glycerol and free fatty acids. the free fatty acids rapidly bind with calcium, forming soaps, causing white, calcified specks

Question 37

Difference between wet and dry gangrene?

Answer 37

Necrotic tissue can provide a good medium for infection by bacteria. The bacterial infection of coagulated tissue leads to inflammation and a secondary liquefaction clinically known as wet gangrene (I.e. advanced decubitus ulcers). If the necrotic tissue dries out, it becomes black and mummified (dry gangrene)

Question 38

Underlying conditions that contribute to Gangrene?

Answer 38

Such infections frequently occur after an infarction of the intestines or in a limb and are usually caused be atherosclerosis or diabetes

Question 39

What is Dystrophic Calcifications?

Answer 39

Necrotic tissue attracts calcium salts and frequently undergoes calcification.
Refers to the macroscopic deposition of calcium in injured or dead tissues. Represents an extracellular deposition of calcium from the circulation into dead or dying necrotic tissue, often visible to the naked eye, and range from gritty, sand-like grains to firm, rock-hard material.

Question 40

Give Examples of Dystrophic Calcifications?

Answer 40

1. Calcifications in Atherosclerotic coronary arteries contributes to narrowing of the vesels
2. Calcifications of the Mitral or Aortic valves leading to impeded blood flow (Stenosis)
3. Calcifications seen around breast cancers that can be visualized by mammography.
4. Infant periventricular calcifications seen in congenital Toxoplasmosis.

Question 41

What are Metastatic Calcifications?

Answer 41

Reflects deranged calcium metabolism (not cell injury), usually associated with increased serum calcium levels, leading to deposition of calcium in other locations.

Question 42

Give examples of Metastatic Calcifications?

Answer 42

Seen in various disorders including Hyperparathyroidism, Vitamin D toxicity, and Chronic Renal Failure. Formations of Calcium stones in sites such as the gallbladder, kidney and bladder are due to precipitation of the salts from solution into tissues.