fetal neural axis Flashcards
Anencephaly is also know as …
aprosencephaly or atelacephaly
The most common neural tube defect
anencephaly
Anencephaly which means absence of the _____, is caused by failure of closure of the neural tube at the cranial end,
brain
In anencephaly the reminate brain is covered by a thick membrane called _________ or _________.
angiomatous stroma, cerebrovasculosa
Anencephaly is a lethal disorder, with up to ____ of cases resulting in fetal demise.
50%
Acrania, also known as _________, is a lethal anomaly that manifests as absence of the cranial bones with the presence of complete, although abnormal, development of the cranial hemispheres.
exencephaly
A neural tube defect in which the meninges alone or the meninges and the brain herniate through a defect in the calvarium.
cephalocele
A term used to describe herniation of the meninges AND brain through the defect.
enecphalocle
Describes the herniation of only the meninges
cranial meningocele
Cepholoecles occur at a rate of 1-3 in _______ live births.
10,000
In ____ of cases cephaloceles are located at the midline and involve the occipital bone.
75%
Chromosomal anomalies and syndromes have been identified with cephoceles, including trisomy ___ and ________.
13, Meckel-Gruber syndrome
Meckel-Gruber syndrome is an autosomal-recessive disorder characterized by encephalocele, _________ , and _________.
polydactyly, polycystic kidneys
Cephaloceles located off midline are usually the result of __________.
ammniotic band syndrome
Cephaloceles maybe confused with _________ although they lack a cranial defect.
cystic hygroma
Encompasses a wide range of vertebral defects that result from failure of neural tube closure.
spina bifida
Spina Bifida occurs most commonly along the _______ and ______ regions.
lumbar, sacral
Results from the abnormal cleavage of the prosencephalon (forebrain)
holoprosencephaly
Holoprosencephaly is often associated with ______ abnormalities.
facial
Facial anomalies identified with holoprosencephaly…
cyclopia, hypertelorism, an absent nose, a flattened nose with single nostril, and proboscios (think trisomy 13)
Consists of the combination of hyoptelorism with a normally placed nose with a single nostril.
cebocephaly
Severe hypotelorism with a proboscis superior to the eyes.
ethmocephaly
Chromosomal anomalies must also be considered if holoprosencephaly is present, especially _________.
trisomy 13
The _________ is a fiberous tract that connects the cerebral hemispheres and aids in learning and memory.
corpus callosum
