Lecture 13 3/7/24 Flashcards
What is agenesis/aplasia?
absence of growth
What is atresia?
absence of the lumen
What are the potential causes of agenesis, aplasia, and atresia?
-can be unknown
-genetics
-teratogens/defect-causing drugs
What is amelia?
limb agenesis
How does atresia differ from stenosis?
-atresia is the absence of a lumen/opening; congenital
-stenosis is the narrowing of an opening; usually acquired
When can stenosis be congenital?
-narrowing of the heart valves
-stenotic nares
What are the characteristics of dysgenesis?
-abnormal growth or development
-often genetic
What is chondrodysplasia?
abnormal growth plates
What type of disturbance of growth does hip dysplasia fall into?
dysgenesis
What is palatoschisis?
cleft palate
What is the consequence of cleft palate?
possible aspiration
What are the characteristics of hypoplasia?
-decreased size due to a decreased number of cells
-organ never reaches normal size
-can be genetic, of unknown cause, or due to viruses
What happens if there is hypoplasia of the melanocytes?
sparse pigmentation
What happens if there is hypoplasia of the autonomic ganglion cells?
-colonic agangliosis
-abnormal movement/development of colon in utero
-small, hypomotile colon in neonate
What is lethal white foal syndrome?
lack of colonic ganglia and melanocytes
Which virus is known to cause cerebellar hypoplasia in cats?
feline panleukopenia - can infect kittens in utero if mother becomes infected
What are the characteristics of cellular adaptations?
-acquired
-reversible
-change in size, number, phenotype, metabolic activity, or function in response to environmental changes
What are the characteristics of hypertrophy?
-increase in cell size
-increased synthesis of cell components
-response to increased functional demand
What are the characteristics of hyperplasia?
-increase in number of cells
-increased cell division
-only possible in cell populations capable of mitosis
How does hyperplasia differ from neoplasia?
-hyperplasia generally subsides if initial stimulus is removed
-stimulated by inflammation, trauma, hormones, or increased functional demand
-hyperplasia may be diffuse or nodular
Which stimulus typically causes diffuse hyperplasia?
hormone-driven
What are the types of nodular hyperplasia?
-compensatory/wound healing
-idiopathic/age-associated
What are the characteristics of atrophy?
-decrease in size and/or number of cells
-occurs after organ has achieved normal size
What are the causes of atrophy?
-normal involution
-pressure-mediated
-idiopathic
-immune-mediated
-decreases in:
–blood supply
–nutrients
–innervation
–use
–hormone stim.
How does hypoplasia differ from atrophy?
-hypoplasia is congenital; organ never reaches full size
-atrophy is acquired; organ reaches normal size and then gets smaller
What are the characteristics of metaplasia?
-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
What are the characteristics of dysplasia?
-pre-neoplastic
-disordered organization
Which atypical microscopic features are seen in dysplasia?
-abnormal variation in size and/or shape
-increased nuclear size
-increased nucleolar size and/or number
-increased mitotic figures
How does dysplasia differ from metaplasia?
-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
How does dysplasia differ from dysgenesis?
-dysplasia is disorganization of tissue components; reversible and pre-neoplastic
-dysgenesis is abnormal growth of a tissue; congenital
