Lecture 13 3/7/24

Question 1

What is agenesis/aplasia?

Answer 1

absence of growth

Question 2

What is atresia?

Answer 2

absence of the lumen

Question 3

What are the potential causes of agenesis, aplasia, and atresia?

Answer 3

-can be unknown
-genetics
-teratogens/defect-causing drugs

Question 4

What is amelia?

Answer 4

limb agenesis

Question 5

How does atresia differ from stenosis?

Answer 5

-atresia is the absence of a lumen/opening; congenital
-stenosis is the narrowing of an opening; usually acquired

Question 6

When can stenosis be congenital?

Answer 6

-narrowing of the heart valves
-stenotic nares

Question 7

What are the characteristics of dysgenesis?

Answer 7

-abnormal growth or development
-often genetic

Question 8

What is chondrodysplasia?

Answer 8

abnormal growth plates

Question 9

What type of disturbance of growth does hip dysplasia fall into?

Answer 9

dysgenesis

Question 10

What is palatoschisis?

Answer 10

cleft palate

Question 11

What is the consequence of cleft palate?

Answer 11

possible aspiration

Question 12

What are the characteristics of hypoplasia?

Answer 12

-decreased size due to a decreased number of cells
-organ never reaches normal size
-can be genetic, of unknown cause, or due to viruses

Question 13

What happens if there is hypoplasia of the melanocytes?

Answer 13

sparse pigmentation

Question 14

What happens if there is hypoplasia of the autonomic ganglion cells?

Answer 14

-colonic agangliosis
-abnormal movement/development of colon in utero
-small, hypomotile colon in neonate

Question 15

What is lethal white foal syndrome?

Answer 15

lack of colonic ganglia and melanocytes

Question 16

Which virus is known to cause cerebellar hypoplasia in cats?

Answer 16

feline panleukopenia - can infect kittens in utero if mother becomes infected

Question 17

What are the characteristics of cellular adaptations?

Answer 17

-acquired
-reversible
-change in size, number, phenotype, metabolic activity, or function in response to environmental changes

Question 18

What are the characteristics of hypertrophy?

Answer 18

-increase in cell size
-increased synthesis of cell components
-response to increased functional demand

Question 19

What are the characteristics of hyperplasia?

Answer 19

-increase in number of cells
-increased cell division
-only possible in cell populations capable of mitosis

Question 20

How does hyperplasia differ from neoplasia?

Answer 20

-hyperplasia generally subsides if initial stimulus is removed
-stimulated by inflammation, trauma, hormones, or increased functional demand
-hyperplasia may be diffuse or nodular

Question 21

Which stimulus typically causes diffuse hyperplasia?

Answer 21

hormone-driven

Question 22

What are the types of nodular hyperplasia?

Answer 22

-compensatory/wound healing
-idiopathic/age-associated

Question 23

What are the characteristics of atrophy?

Answer 23

-decrease in size and/or number of cells
-occurs after organ has achieved normal size

Question 24

What are the causes of atrophy?

Answer 24

-normal involution
-pressure-mediated
-idiopathic
-immune-mediated
-decreases in:
–blood supply
–nutrients
–innervation
–use
–hormone stim.

Question 25

How does hypoplasia differ from atrophy?

Answer 25

-hypoplasia is congenital; organ never reaches full size
-atrophy is acquired; organ reaches normal size and then gets smaller

Question 26

What are the characteristics of metaplasia?

Answer 26

-reversible
-one differentiated cell type is replaced by another
-response to injury or stress
-new epithelium is more resistant to injury, less specialized, and has poor functional performance

Question 27

What are the characteristics of dysplasia?

Answer 27

-pre-neoplastic
-disordered organization

Question 28

Which atypical microscopic features are seen in dysplasia?

Answer 28

-abnormal variation in size and/or shape
-increased nuclear size
-increased nucleolar size and/or number
-increased mitotic figures

Question 29

How does dysplasia differ from metaplasia?

Answer 29

-dysplasia is disorganization of tissue components, and
is pre-neoplastic
-metaplasia is a change from one cell type to another, but cells still look normal
-both are reversible

Question 30

How does dysplasia differ from dysgenesis?

Answer 30

-dysplasia is disorganization of tissue components; reversible and pre-neoplastic
-dysgenesis is abnormal growth of a tissue; congenital