Chapter 59- Fetal Neural Axis

Question 1

condition associated with anencephaly in which there is complete or partial absence of the cranial bones

Answer 1

acrania

Question 2

most severe form of holoprosencephaly characterized by a single common ventricle and malformed brain; orbital anomalies range from fused orbits to hypotelorism, with frequent nasal anomalies and clefting of the lip and palate

Answer 2

alobar holoprosencephaly

Question 3

neural tube defect characterized by lack of development of the cerebral and cerebellar hemispheres and cranial vault; this abnormality is incompatible with life

Answer 3

anencephaly

Question 4

abnormality or congenital malformation

Answer 4

anomaly

Question 5

form of holoprosencephaly characterized by a common ventricle, hypotelorism, and a nose with a single nostril

Answer 5

cebocephaly

Question 6

severe form of holoprosencephaly characterized by a common ventricle, fusion of the orbits with one or two eyes present, and a proboscis (maldeveloped cylindrical nose)

Answer 6

cyclopia

Question 7

an increase in size of the jugular lymphatic sacs caused by abnormal development

Answer 7

cystic hygroma

Question 8

a range of abnormalities from abnormal cleavage of the forebrain

Answer 8

holoprosencephaly

Question 9

congenital absence of the cerebral hemispheres caused by an occlusion of the carotid arteries; midbrain structures are present, and fluid replaces cerebral tissue

Answer 9

hydranencephaly

Question 10

ventriculomegaly in the neonate; abnormal accumulation of cerebrospinal fluid within the cerebral ventricles, resulting in compression and frequently in destruction of brain tissue

Answer 10

hydrocephalus

Question 11

enlargement of the fetal cranium as a result of ventriculomegaly

Answer 11

macrocephaly

Question 12

open spinal defect characterized by protrusion of the spinal meninges

Answer 12

meningocele

Question 13

open spinal defect characterized by protrusion of meninges and spinal cord through the defect, usually within a meningeal sac

Answer 13

meningomyelocele

Question 14

neural tube defect of the spine in which the dorsal vertebrae (vertebral arches) fail to fuse together, allowing the protrusion of meninges and/or spinal cord through the defect; two types exist: spina bifida occulta (skin-covered defect of the spine without protrusion of meninges or cord) and spina bifida cystica (open spinal defect marked by sac containing protruding meninges and/or cord)

Answer 14

spina bifida

Question 15

closed defect of the spine without protrusion of meninges or spinal cord; alpha-fetoprotein analysis will not detect these lesions

Answer 15

spina bifida occulta

Question 16

abnormal accumulation of cerebrospinal fluid within the cerebral ventricles resulting in dilatation of the ventricles; compression of developing brain tissue and brain damage may result; commonly associated with additional fetal anomalies

Answer 16

ventriculomegaly