1.1 Growth Adaptations Flashcards
1
Q
Hyperplasia, examples of physiologic and pathologic
A
Increase number of cells from stem cells
- Physiologic: Uterus during pregnancy (also hypertrophy)
- Pathologic: endometrial hyperplasia, BPH
2
Q
Hypertrophy, mech and 1 example
A
Increase in size of cells.
- mech: gene activation, protein synthesis, organelle production
- Cardiac myocyte hypertrophy
3
Q
Atrophy, mechanism
A
Decrease in cell number
- mech:
- ubiquitin-proteosome degradation of cytoskeleton (intermediate filaments are tagged by ubuiqitin)
- autopaghy of cellular components (autophagic vacuoles fuse with lysosomes)
4
Q
Metaplasia, mech and 3 examples
A
Change in cell type
- mech: reprogramming of stem cells
- Usually surface epithelium
- Ex: Barrett’s esophagus, Vit A deficiency, myositis ossificans
5
Q
Barrett’s esophagus
A
- Ex of metaplasia
- Acid from GERD turns stratified squamous into simple columnar
6
Q
Vit A deficiency
A
- ex of metaplasia
- Columnar epithelium of conjunctiva turns into keratinized squamous epithelium, leading to destruction of cornea (keratomalacia) and blindness
7
Q
Keratomalacia
A
- Metaplasia of conjunctiva from Vit A deficiency.
- columnar into keratinized squamous epithelium
- blindness
8
Q
Dysplasia: 1 example, it is reversible?
A
Disordered cellular growth
- usually proliferation of precancerous cells
- ex: Cervical intraepithelial neoplasia (CIN) is precursor to cervical cancer
- reversible, but can progress to irreversible carcinoma
9
Q
Aplasia, 1 example
A
Failure of cell production during embryogenesis
-ex: unilateral renal agenesis
10
Q
Hypoplasia, 1 example
A
Decrease in cell production during embryogenesis, leading to small organ
-ex: streak ovary in Turner syndrome
11
Q
Myositis ossificans
A
- ex of metaplasia
- after trauma, connective tissue in muscle turns into bone during healing
