1.1 Growth Adaptations Flashcards
What is hypertrophy?
Increase in cell size
What is hyperplasia?
Increase in cell number
What are the two processes that underlie hypertrophy?
- Gene activation/Protein synthesis
- Production of organelles
True or false: hyperplasia and hypertrophy usually occur separately
False– usually together
Why is it that permanent cells such as the heart and brain cannot undergo hyperplasia?
They do not have stem cells–thus only hypertrophy
What are the three major permanent tissues in the body?
Cardiac myocyte
Skeletal muscles
Nerves
What is the classic example of physiologic hypertrophy?
Uterine expansion during pregnancy
What can pathologic hyperplasia progress to?
Dysplasia
Does BPH progress to cancer?
No
What are the two processes that underlie atrophy?
- Apoptosis of cells
- Decrease in cell size
What is the pathway the cells have to degrade cellular proteins (e.g. cytoskeletal)
Ubiquitin-proteasome pathway
What is the mechanism through which cells reduce the number of organelles?
Autophagy–degrade organelles via lysosomes
What is the underlying process of metaplasia?
Change in cell stress leads to a change in cell type to better handle the stresses placed upon it
What type of cells most often undergo metaplasia?
Surface epithelium
What is the classic example of metaplasia?
Barrett’s esophagus–goes from squamous to columnar epithelium with goblet cells
What is the main underlying process that occurs with metaplasia?
Reprogramming of stem cells
Is metaplasia reversible?
Yes
What is the major problem with metaplasia?
Progression to dysplasia
What is the one exception to the general rule, that metaplasia will progress to dysplasia?
Apocrine glands
t(15;17) translocation = ?
ALL (acute promyelocytic leukemia) that is treated with ATRA
What is the role of vitamin A in the development of the immune system?
Needed for maturation
What is the pathophysiology of keratomalacia?
Lack of vitamin A causes a metaplasia of the conjunctiva of the eye, leading to thicker epithelium and blindness
What are mesenchymal tissue?
Bone
Cartilage
Fat
CT
What is myositis ossificans?
Inflammation of skeletal muscle (usually d/t trauma) causes metaplasia to bone
What is dysplasia?
Disordered cellular growth that arises from longstanding pathologic hyperplasia or metaplasia
Is dysplasia reversible?
Yes
What is aplasia?
Failure of cell production during embryogenesis
What is hypoplasia?
Decrease in cell production during embryogenesis
What is the streak ovary that can occur in Turner’s syndrome?
a form of aplasia in which the ovary is replaced by functionless tissue. The accompanying hormonal failure also prevents the development of secondary sex characteristics
