Developmental Anomalies (Ex3) Flashcards
What are the types of anatomic defects?
- failure to fuse
- failure to canalize/separate
- cysts
- failure of a structure to develop
- abnormal development of a structure
- ectopic development
Explain the pathogenesis of arthrogryposis
- limbs do not move during development
- muscles don’t develop correctly
- connective tissue matures
- limbs are fixed in place
What is hydraencephaly?
- cerebral hemispheres have not developed
- affected calves called dumby cows
What are the four main causes of developmental anomalies?
- genetic defect
- in-utero infection
- in-utero exposure to teratogens
- in-utero nutritional deficiencies
What is palatoschisis?
What is the etiology?
- failure of the roof of the mouth to fuse
- cleft palate
- Griseofulvin (teratogen)
What is synophthalmia?
What is the etiology?
failure of the orbit to separate
- ingestion of veratrum californicum at day 14 of gestation
Define aplasia
failure to develop
What are the 4 genetic etiologies of developmental anomalies?
- inherited genes: often autosomal recessive
- spontaneous somatic genetic defect
- chromosomal anomalies
- breed dispositions
What is spina bifida?
cleft in the dorsal tissues of the spine
What is cheiloschisis?
cleft lip
What is hypospadias?
cleft in the penis, exposing the urethra
What is coloboma?
cleft in the internal structures of the eye
What is intraventricular cardiac septal defect?
a hole communicating between the ventricles of the heart
What is meningeoencephalocele?
failure to fuse of the skull
Define atresia
failure to canalize
What is polydactyly?
too many digits
What is polymelia?
too many limbs
Describe biochemical defects
- involve an inability to synthesize adequate amounts of a particular enzyme or other protein
- usually no grossly visible malformations
- usually due to genetic mutation
What is mannosidosis?
- vacuolar neuronal degeneration
- due to genetic defect for mannosidase
- mannis accumulates in cytoplasm, so neurons unable to function normally
What are lysosomal storage disease?
How do they appear histologically?
What cells are most susceptible?
- genetic deficiency of particular lysosomal enzymes
- histo: vacuoles filled with the accumulated substrate of the deficient enzyme
- post-miotic cells most susceptible: neurons, skeletal and cardiac muscle
What is Neiman Pick disease?
- vacuolar neuronal degeneration
- genetic defect for sphingomyelinase
