Chap1: Growth Adaptations Flashcards
Define hypertrophy
increase in size of cell
define hyperplasia
increase in number of cell
MOA for hypertrophy
gene activation
protein synthesis
production of organelles
MOA for hyperplasia
production of new cells from stem cells
Give an example when hyperplasia and hypertrophy occur together
uterus duging pregnancy
name 3 permanent cells in the body
cardiac muscle
skeletal muscle
nerve
do permanent cells undergo hyperplasia or hypertrophy
hypertrophy only
what is an example of a pathologic hyperplasia that does increase the risk of cancer
Benign prostatic hyperplasia
define atrophy
decrease in stress leads to decrease in organ size and/or decrease in number and/or size
in atrophy how does it decrease cell number
apoptosis
In atrophy what are 2 processes that decrease size
- ubiquitin-proteosome degradation
2. autophagy of cellular components
what happens in the ubiquitin-proteosome degradation
ubiquitin- tags on intermediate filaments of the cytoskeleton
proteosomes - destroy them
what happens in autophagy of cellular components
generation of autophagic vacuoles
-vacuoles fuse with lysosomes ( hydrolytic enzymes break down cellular components)
define metaplasia
change in stress on an organ leads to a change in cell type
why does metaplasia occur
metaplastic cells are better able to handle the new stress
What is the classic examples of metaplasia
Barrett esophagus
what is the epithelium lining of the esophagus
nonkeratinizing squamous epithelium
acid reflex from the stomach causes metaplasia of the lower esophagus to turn into what
non-ciliated, mucin-producing columnar cells
Metaplasia occurs via _____, which then produce the new cell type
reprogramming of stem cells
Metaplasia is ___ in theory, with removal of the driving stressor
reversible
Under persistent stress, metaplasia can progress to what
dysplasia and eventually result in cancer
what type of metaplasia carries no increased risk of cancer
apocrine metaplasia of breast
A deficiency in what vitamin can result in metaplasia
vitamin A
Vitamin A is necessary for differentiation of what epithelium cells
columnar epithelium of conjunctiva
during vitamin A deficiency what metaplasia occurs
goblet cell/columnar epithelium of conjunctiva into keratinizing squamous epithelium
xerophthalmia
dry eye
Xerophthalmia leads to the destruction of what
cornea: keratomalacia –> blindness
keratomalacia
destruction of cornea
what is a classic examples of mesenchymal tissue undergoing metaplasia
myositis ossificans
-tissue within muscle changes to bones during healing after trauma
define dysplasia
disordered cellular growth
-proliferation of precancerous cells
Give an example of dysplasia
cervical intraepithelial neoplasia (CIN)
dysplasia is ___, in theory with alleviation of inciting stress. If stress persists, dysplasia progress to carcinoma which is ____
reverisble
irreversible
define aplasia
failure of cell production during embryogensis
define hypoplasia
decrease in cell production during embryogenesis, resulting in a relatively small organ.
name an example of aplasia
unilateral renal agenesis
name an example of hypoplasia
streak ovary in Turner syndrome
name 5 growth adaptations
- Hyperplasia/hypertrophy
- Atrophy
- Metaplasia
- Dysplasia
- Aplasia/hypoplasia
