Cell Adaptations

Question 1

Define hypertrophy in histological terms.

Answer 1

Increase in size of organ, above normal, due to increase in CELL SIZE

Question 2

Define atrophy in histological terms.

Answer 2

Decrease in size and/or volume of cells and tissue in an organ

Question 3

Define hyperplasia in histological terms.

Answer 3

Increase in size of organ, above normal, due to increase in CELL NUMBER

Question 4

Define metaplasia in histological terms.

Answer 4

Change in cell phenotype, i.e., a change in one differentiated phenotype to another

The replacement of one adult cell type by another adult cell type

Usually in places with chronic irritation

Question 5

Define dysplasia in histological terms.

Answer 5

Failure to differentiate completely

Tissue alterations characterized by architectural and cytologic disorder

ALWAYS pathologic

Question 6

Describe the changes that occur in Barrett’s esophagus. What are the four stages of this process?

Answer 6

A pathophysiologic response to chronic GI reflux -> inflammatory injury to the esophagus

1. Hyperplasia of normal stratified squamous lining
2. Intestinal type metaplasia (Barrett esophagus, Goblet cells present!)
   - —Looks like colon!
3. Dysplasia (pre-neoplasia)
4. Cancer (adenocarcinoma)

Question 7

Describe the changes occurring in “dysplasia” as a process. (4)

Answer 7

Abnormal maturation
Increased replication
Increased mitoses
Disordered proliferation

Question 8

Name the specific organs/tissues that exhibit physiological hyperplasia. (2)

Answer 8

Prostate (with BPH)

Breast (with pregnancy)

Question 9

Name the specific organs/tissues that exhibit physiological hypertrophy. (1)

Answer 9

Myocardium (with HTN)

Question 10

Name the specific organs/tissues that exhibit physiological atrophy. (4)

Answer 10

Testes (with age): lose seminiferous tubules

Skeletal muscle (with amputation, nerve damage, prolonged inactivity)

Prostate glands in prostate: become small, condensed, with little cytoplasm

Breast (with age)

Question 11

Define aplasia.

Answer 11

Absence of growth

Question 12

Define differentiation. How is it seen at the cellular and tissue level?

Answer 12

Development of an “adult” cellular phenotype

Cellular level: development of cytoplasmic organelles and products

Tissue level: organization of cells as well as individual cell phenotype

Question 13

Define parenchyma.

Answer 13

The characteristic differentiated functional cells of an organ (i.e. hepatocytes)

Question 14

Define stroma.

Answer 14

The connective tissue and vascular framework of a tissue

Question 15

What signals control growth and differentiation? (6)

Answer 15

Trophic hormones
Growth factors
Growth inhibitor hormones/peptides
Work load
Xenobiotics
Blood supply and basic nutrients

Question 16

What changes would you expect to see in atrophying skeletal muscle? (3) What could cause this? (3)

Answer 16

Changes:

• Small muscle fibers (more pale)
• Enlarged muscle nuclei
• Increased interstitial collagen

Causes: amputation, nerve damage, prolonged inactivity

Question 17

What changes would you expect to see in hypertrophy of myocardium? (2) What could cause this? (3)

Answer 17

Changes:

• Increased length and size of fibers
• Bigger nuclei [boxcar nuclei]

Causes: aortic stenosis, hypertension, lot of cardio

Question 18

What changes would you expect to see in hyperplasia of the breast? (3) What could cause this? (1)

Answer 18

Changes:

• Very enlarged acini/glands
• Thin septa
• Luminal milk secretions

Causes: pregnancy (lactation)

Question 19

What changes would you expect to see in hyperplasia of the prostate? (3) How about metaplasia? (2) What could cause this? (1)

Answer 19

Changes with hyperplasia:

• Nodular overgrowth
• –Nodule = a whole sack of glands
• Wider space between glands
• Sometimes glandular hyperplasia (-> complex infolding)

Changes with metaplasia:

• Squamous metaplasia in glands (versus normal 2-layered glands)
• Corpora amylacea (also in normal)

Causes: age

Question 20

What changes would you expect to see in osseous metaplasia? What could cause this?

Answer 20

Changes:

• Large areas of bone and cartilage in CT outside of arterial adventitia
• Bone = irregular PINK spicules

Cause: uncertain, can occur as metaplasia in scars

Question 21

Name the specific organs/tissues that exhibit metaplasia and the type of metaplasia seen in each. (3)

Answer 21

Places with chronic irritation

Bronchi: squamous metaplasia (from respiratory epithelium [ciliated pseudostratified columnar epithelium])

Esophagus (as in Barrett’s esophagus)

Cervix: squamous metaplasia (from secretory columnar)

Question 22

List the examples given of specific organs/tissues that exhibit dysplasia and the type of dysplasia seen in each. (3)

Answer 22

Bronchial (squamous) dysplasia:

• Disorderly architecture
• Enlarged and hyperchromatic nuclei
• Abnormal mitotic figures

Esophageal (Barrett’s) dysplasia: glandular dysplasia

• Cells darker, more compact (lose mucous secretions)
• Nuclei elongated, mitosing
• Cells more plump and round

Cervical dysplasia: squamous dysplasia (from HPV)

• Enlarged and hyperchromatic nuclei
• Disordered epithelial cell growth
• Loss of cellular maturation
• Abnormal mitotic figures

Question 23

Where SHOULD mitosis take place in stratified squamous epithelium?

Answer 23

The basal layer

Question 24

What changes would you expect to see in atrophy of the breast? (2) What could cause this? (1)

Answer 24

Changes:

• Increased fibrous tissue
• Atrophy of epithelial/glandular tissue

Causes: age