4. Cell Injury: Cellular Adaptations

What might happen if the cell injury is reversible and chronic?

the cells may adapt

What are the different types of cellular adaptations?

H
H
M
D
A
A

• hypertrophy

• hyperplasia

• metaplasia

• dysplasia

• anaplasia

• atrophy

immature cells with differentiated cells

dysplasia

loss of structural and functional dedifferentiation and is sometimes associated with neoplasia

anaplasia

increase in mass and volume of tissue or organ from increased cell size not cell number

hypertrophy

What factors can contribute to hypertrophy?

G
H
I

• growth factors

• hormones

• increased workload

True or false: Hypertrophy can also be accompanied by an increase in cell number. Specific tissues like the heart or skeletal muscle, hypertrophy can stand alone.

true

True or false: Hypertrophy must be distinguished from other processes which enlarge organs/tissues such as cell swelling or inflammation.

true

What is this an example of?

hypertrophy

Most often, what is smooth muscle hypertrophy in response to? What is the cause of the increased workload?

increased workload; unknown

What is this an example of?

hypertrophy

an increase in cell number rather than cell size, which can increase the size of the organ itself

hyperplasia

Hyperplasia only occurs in what population of cells?

ones that are capable of mitosis

What cells readily undergo hyperplasia?

epithelial cells

What cells have an intermediate capability to undergo hyperplasia?

smooth muscle, bone, and cartilage

What cells do not tend to undergo hyperplasia?

striated muscle and nervous tissue

What cells can’t have hyperplasia? What are examples?

post-mitotic cells; cardiac and neuro tissues

What are the two main causes of hyperplasia?

physiologic or pathologic

What is a physiologic reason for hyperplasia?

hormonal/compensatory

What is a pathologic reason for hyperplasia?

excessive hormones or chronic irritation

What is this an example of?

hyperplasia

What is this an example of?

hyperplasia

decrease in mass of tissue/organ from decreased cell size after it has reached normal size

atrophy

What is the overall cause of atrophy?

decreased cell size due to a loss of mitochondria or other organelles or a loss of its principle cells

What are some specific causes of atrophy?

N
L
D
D
A

• nutrient deprivation

• loss of stimulation by trophic hormones or growth factors

• decreased workload

• denervation

• autophagy or apoptotic cell death

What is this an example of?

atrophy

What is this an example of?

atrophy

What is this an example of?

atrophy (thymic)

specific type of atrophy which results from prolonged negative energy states

serous atrophy of fat or gelatinous transformation of fat

From which type of negative energy states is serous atrophy of fat/gelatinous transformation of fat resultant of?

C
C

• chronic emaciation

• cachexia

In serous atrophy of fat, or gelatinous transformation of fat, the adipocytes loose their normal ________ structure, and are replaced by a ________ rich matrix.

lipid; glycosaminoglycan

Where are the most common locations to appreciate the changes associated with serous atrophy of fat, or gelatinous transformation of fat?

epicardial adipose at the location of the coronary arteries and within the diaphysis of long bones

Grossly, how does serous atrophy of fat, or gelatinous transformation of fat present? How should normal fat present?

adipose is replaced with a gelatinous clear to red tinged material; should be yellow

What is this an example of?

serous atrophy of fat or gelatinous transformation of fat

What is this an example of?

serous atrophy of fat or gelatinous transformation of fat

failure of an organ or tissue to fully develop

hypoplasia

True or false: Distinguishing between atrophy and hypoplasia can be difficult grossly, and sometimes requires histologic discernment.

true

What is this an example of?

hypoplasia

replacement of one cell type with another

metaplasia

Why do cells undergo metaplasia?

it is an adaptation response to chronic reversible injury

What can happen with metaplasia if the cause is removed?

it can be reversible

What can metaplasia progress to?

neoplasia

What are causes of metaplasia?

C
H
V
T

• chronic inflammation

• hormonal imbalances

• vitamin A deficiency

• trauma

What is this an example of?

metaplasia

What is this an example of?

metaplasia

abnormality in the formation of a tissue or the increase in the number of poorly differentiated or immature cells

dysplasia

What can dysplasia be a precursor to?

neoplasia

True or false: Dysplasia is almost never diagnosed grossly, and will typically be diagnosed histopathically.

true

What is this an example of?

dysplasia

What is this an example of?

osseous metaplasia

What is this an example of?

dysplasia

What cellular adaptation would you expect to see with this disease?

atrophy