What destroys ubiquitin tagged proteins? Correct Ans-Proteosomes
Autophagy Correct Ans-Cell consumes its own components in vacuoles, which fuse with
lysozomes, whose hydrolytic enzymes breakdown the cellular components in the vacuoles
What are the two processes in atrophy that can decrease cell size Correct Ans-Ubiquitin-
proteosome degradation (to decrease cytoskeleton) and autophagy (to decrease organelles)
What promotes metaplasia? Correct Ans-A change in stress on a cell --> change in cell type
(metaplasia)
What is Epithelium? Correct Ans-Cells that line body surfaces
What type of cells are most commonly involved in metaplasia? Correct Ans-Change of one
type of surface epithelium to another (i.e. squamous, columnar, urethelial/transitional)
Barrett's Esophagus Correct Ans-Non-keratinized squamous epithelium of the esophagus
becomes non-ciliated, mucin producing columnar cells (normal cell in stomach)
This is done to better handle the stress of acid reflux in the esophagus
Is metaplasia reversible? Correct Ans-Yes, in theory, with the removal of the driving
stressor
, Pathoma Chapter 1- Questions and Answers
Ex/ treatment of GERD may reverse Barrett esophagus
How does metaplasia occur? Correct Ans-Via reprogramming of stem cells, which then
produces a new cell type
Metaplasia to cancer pathway Correct Ans-Metaplasia --> dysplasia --> cancer
Barrett esophagus can progress to ___ if under persistent stress? Correct Ans-
adenocarcinoma of esophagus
What type of metaplasia does not produce an increase in cancer risk? Correct Ans-
Apocrine metaplasia of the breast, which is seen in fibrocystic change of the breast
What vitamin deficiency can result in metaplasia? Correct Ans-Vitamin A deficiency
Why is Vitamin A necessary? Correct Ans-It is necessary for the differentiation of
specialized epithelial surfaces such as the conjunctiva covering the eye (causes night
blindness!!); also necessary for maturation of the immune system
What happens to the conjunctiva of the eye during Vitamin A deficiency? Correct Ans-
Undergoes metaplasia from goblet cell/columnar epithelium to keratinizing squamous
epithelium (leading to dry eyes --> destruction of cornea --> blindness)
, Pathoma Chapter 1- Questions and Answers
Xerophthalmia Correct Ans-Dry eyes (caused by vitamin A deficiency and metaplasia); can
lead to keratomalacia
What leads to an increase in organ size? Correct Ans-Increase in stress
What are the two processes via which an organ can increase in size? Correct Ans-
Hyperplasia (increase in number of cells) and hypertrophy (increase in size of cells)
What are three processes/events that occur in hypertrophy? Correct Ans-Gene activation,
protein synthesis, production of organelles
Where do the new cells in hyperplasia come from? Correct Ans-Stem cells
What tissues cannot undergo hyperplasia, only hypertrophy? Correct Ans-Permanent
tissue, i.e. skeletal muscle, cardiac muscle, nerve tissue
What is the only type of muscle that can undergo hyperplasia? Correct Ans-Smooth muscle
(i.e. uterus)
How do cardiac myocytes respond to hypertension? Correct Ans-Hypertrophy, not
hyperplasia
Picture shows left ventricular hypertrophy