Cell Adaptations Flashcards
Define hypertrophy in histological terms.
Increase in size of organ, above normal, due to increase in CELL SIZE
Define atrophy in histological terms.
Decrease in size and/or volume of cells and tissue in an organ
Define hyperplasia in histological terms.
Increase in size of organ, above normal, due to increase in CELL NUMBER
Define metaplasia in histological terms.
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
Define dysplasia in histological terms.
Failure to differentiate completely
Tissue alterations characterized by architectural and cytologic disorder
ALWAYS pathologic
Describe the changes that occur in Barrett’s esophagus. What are the four stages of this process?
A pathophysiologic response to chronic GI reflux -> inflammatory injury to the esophagus
- Hyperplasia of normal stratified squamous lining
- Intestinal type metaplasia (Barrett esophagus, Goblet cells present!)
- —Looks like colon! - Dysplasia (pre-neoplasia)
- Cancer (adenocarcinoma)
Describe the changes occurring in “dysplasia” as a process. (4)
Abnormal maturation
Increased replication
Increased mitoses
Disordered proliferation
Name the specific organs/tissues that exhibit physiological hyperplasia. (2)
Prostate (with BPH)
Breast (with pregnancy)
Name the specific organs/tissues that exhibit physiological hypertrophy. (1)
Myocardium (with HTN)
Name the specific organs/tissues that exhibit physiological atrophy. (4)
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)
Define aplasia.
Absence of growth
Define differentiation. How is it seen at the cellular and tissue level?
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
Define parenchyma.
The characteristic differentiated functional cells of an organ (i.e. hepatocytes)
Define stroma.
The connective tissue and vascular framework of a tissue
What signals control growth and differentiation? (6)
Trophic hormones Growth factors Growth inhibitor hormones/peptides Work load Xenobiotics Blood supply and basic nutrients
What changes would you expect to see in atrophying skeletal muscle? (3) What could cause this? (3)
Changes:
- Small muscle fibers (more pale)
- Enlarged muscle nuclei
- Increased interstitial collagen
Causes: amputation, nerve damage, prolonged inactivity
What changes would you expect to see in hypertrophy of myocardium? (2) What could cause this? (3)
Changes:
- Increased length and size of fibers
- Bigger nuclei [boxcar nuclei]
Causes: aortic stenosis, hypertension, lot of cardio
What changes would you expect to see in hyperplasia of the breast? (3) What could cause this? (1)
Changes:
- Very enlarged acini/glands
- Thin septa
- Luminal milk secretions
Causes: pregnancy (lactation)
What changes would you expect to see in hyperplasia of the prostate? (3) How about metaplasia? (2) What could cause this? (1)
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
What changes would you expect to see in osseous metaplasia? What could cause this?
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
Name the specific organs/tissues that exhibit metaplasia and the type of metaplasia seen in each. (3)
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)
List the examples given of specific organs/tissues that exhibit dysplasia and the type of dysplasia seen in each. (3)
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
Where SHOULD mitosis take place in stratified squamous epithelium?
The basal layer
What changes would you expect to see in atrophy of the breast? (2) What could cause this? (1)
Changes:
- Increased fibrous tissue
- Atrophy of epithelial/glandular tissue
Causes: age
