1.1 Growth Adaptations

Question 1

What are the permanent tissues in the body that do not undergo hyperplasia but only hypertrophy?

Answer 1

Cardiac muscle, Skeletal muscle, Nerves

Question 2

Pathologic hyperplasia can lead to dysplasia and eventually cancer. What is a notable exception to this?

Answer 2

Benign Prostatic Hyperplasia

It does not increase one’s risk of cancer

Question 3

What are the 2 primary processes used by the cell to undergo atrophy?

Answer 3

Ubiquitin-proteosome pathway that breaks down the cytoskeleton
Autophagy that includes formation of autophagic vacuoles containing cellular components that fuse with lysosomes for breakdown

Question 4

What is metaplasia?

Answer 4

Changes in cellular stress lead to a change in cell type to adapt to the stress
Occurs via reprogramming of stem cells that produce the new cells
In most situations it is reversible, but can progress to dysplasia when chronic
Barrett esophagus is classic example

Question 5

What is one example of metaplasia that does not increase risk for cancer?

Answer 5

Apocrine metaplasia in the breast

Question 6

What is a vitamin deficiency that can lead to metaplasia?

Answer 6

Vit A deficiency
Maintains specialized epithelium, deficiency leads to changes in the cells
Example: keratomalacia

Question 7

What growth adaptation is exhibited by myositis ossificans?

Answer 7

Metaplasia

Trauma to muscle leads to connective tissue changing to bone during healing

Question 8

What is dysplasia?

Answer 8

Disordered cell growth
Most often refers to the proliferation of cancerous cells
Often arises after longstanding pathologic hyperplasia or metaplasia
Generally still reversible until it becomes carcinoma at which point it is no longer reversible

Question 9

What are aplasia and hypoplasia?

Answer 9

Aplasia: failure of cell production during embryogenesis
Hypoplasia: decrease in cell production during embryogenesis