1. Growth Adaptations, Injury, Cell Death

Question 1

what are the main types of Growth Adaptations?

Answer 1

hyperplasia, hypertrophy, atrophy, metaplasia, dysplasia

Question 2

what is hyperplasia?

ex?

Answer 2

increase in number of cells, due to increase in stress to organ

Congenital Adrenal Hyperplasia

Benign Prostatic Hyperplasia

Cushing’s Dz

Endometrial Hyperplasia

Question 3

what is hypertrophy?

ex?

Answer 3

increase in size of cells, due to increase in stress to organ

ex = cardiac hypertrophy

Question 4

what processes are involved in hyperplasia?

Answer 4

new cells made from stem cells

Question 5

what tissues cannot perform hyperplasia? why?

Answer 5

cardiac, skeletal muscle, nerve. these are permanent tissues and have no stem cells

Question 6

in response to systemic hypertension, what will the cardiac myocytes do?

Answer 6

hypertrophy, NOT hyperplasia

Question 7

pathologic hyperplasia can lead to what?

Answer 7

dysplasia –> cancer

Question 8

what is an exception to pathologic hyperplasia leading to dysplasia and cancer?

Answer 8

benign prostatic hyperplasia (does not increase the risk for prostate cancer). technically a pathologic hyperplasia still.

Question 9

what are the mechanisms of hypertrophy?

Answer 9

gene activation, protein synthesis, production of organelles.

Question 10

what are the 2 mechanisms of atrophy?

Answer 10

decrease in size of cells decrease in number of cells

Question 11

atrophy: how do the TWO mechs work for decreasing the size of cells?

Answer 11

1. via ubiquitin-proteosome degradation of cytoskeleton: intermediate filaments of cytoskel are tagged with ubiquitin and destroyed by proteosomes 2. autophagy of cellular components: autophagic vacuoles fuse with lysosomes and hydrolytic enzymes break down cellular components.

Question 12

atrophy: how does the mech work for decreasing the number of cells?

Answer 12

apoptosis

Question 13

example of physiologic hyperplasia?

Answer 13

pregnancy

Question 14

def of metaplasia?

Answer 14

change in stress on an organ leads to a change in cell type

Question 15

classic example of metaplasia?

Answer 15

Barrett esophagus

Question 16

what is usually involved in metaplasia?

Answer 16

one type of surface epithelium changes to another

Question 17

why would metaplasia occur?

Answer 17

metaplastic (new) cells are better able to handle the new stress.

Question 18

three main types of surface epithelium?

Answer 18

squamous, columnar, urothelial/transitional

Question 19

explain Barrett esophagus

Answer 19

esophagus epithelium is typically squamous. if acid is in contact with esophag for a prolonged time, squamous tissue will change to columnar, which can better cope with the acid

Question 20

stomach: normal epithelium?

Answer 20

columnar: non-ciliated, mucinous (goblet cells). suited to handle acid

Question 21

esophagus: normal epithelium?

Answer 21

nonkeratinizing squamous (suited to handle friction)

Question 22

how does metaplasia occur?

Answer 22

reprogramming of stem cells

Question 23

metaplasia, dysplasia, carcinoma: which are reversible?

Answer 23

in theory, metaplasia and dysplasia are reversible with removal of stressor

Question 24

Barrett esophagus can progress to what?

Answer 24

metaplasia of Barrett esophagus can progress to adenocarcinoma (dysplasia)

Question 25

what is a risk factor for adenocarcinoma?

Answer 25

Barrett esophag

Question 26

metaplasia can progress to what?

Answer 26

dysplasia

Question 27

metaplasia progressing to dysplasia: exception?

Answer 27

apocrine metaplasia of breast. no increased risk of cancer

Question 28

metaplasia can result from stress and what else?

Answer 28

Vit A deficiency

Question 29

what is the key distinction between dysplasia and cancer?

Answer 29

dysplasia is reversible

Question 30

how does Vit A def result in immunodeficiency?

Answer 30

it is required for maturation of immune cells

Question 31

specific situation in which Vit A def results in metaplasia?

Answer 31

Vit A = required for differentiation of specialized epithelium of conjunctiva. with def, squamous lining of conjunctiva --\> metaplasia into stratified keratinizing squamous epithelium. Keratomalacia Cause of night blindness

Question 32

a classic example of metaplasia involving skel muscle?

Answer 32

myositis ossificans. after trauma, muscle cells in process of healing converts to bone

Question 33

how can you tell the difference between myositis ossificans and osteosarcoma?

Answer 33

MO: nearby bone is NORMAL Osteosarcoma: bone and abnormal growth in muscle are connected.

Question 34

definition of dysplasia

Answer 34

disordered cell growth

Question 35

dysplasia generally refers to what?

Answer 35

proliferation of precancerous cells

Question 36

what type of dysplasia is a precursor to cervical cancer?

Answer 36

CIN: cervical intraepithelial neoplasia

Question 37

dysplasia may arise from what?

Answer 37

metaplasia (ex: Barretts), or pathologic hyperplasia (ex: endometrial hyperplasia)

Question 38

aplasia: definition

Answer 38

failure of cell production during embryogenesis

Question 39

aplasia: example

Answer 39

unilateral renal agenesis

Question 40

hypoplasia: definition

Answer 40

decr in cell production during embryogenesis resulting in relatively small organ

Question 41

hypoplasia: example

Answer 41

streak ovary in Turner syndrome