Brain Anomaly Flashcards
Thickening of the endo
MSD = 2-3mm
Fourth Gest week sono findings
MSD = 10 mm
Yolk sac seen w/ TV
May vis embryonic disc
May vis cardiac activity
Fifth Gest Week sono findings
MSD = 15-20 mm
Yolk sac seen w/ TV
C-Shaped embryo measuring 5 mm
Cardiac Activity should be present
Sixth Gest week sono findings
MSD = 30 mm CRL = 1 cm Cardiac activity should be present Head is 1/2 of embryo Limb buds appear
Seventh gest week sono findings
CRL = 1.5 cm Embryo unfolds Head becomes dominent Midgut has herniated into base of umbilical cord Plac location can be identified Spine may be identified
Eighth gest week sono findings
CRL = 2.3 cm
Can differentiate cerebral hemisphere
Vis limb buds
Early ossification seen
Ninth Gest week sono findings
CRL = 3.0 cm
Muscular movement has begun
Hyperechoic choriod plexus
Cystic rhombencephalon demonstrated in posterior fossa
Tenth Gest week sono findings
CRL= 5.5 cm Yolk sac no longer vis Midgut has returned to abd cavity Amnion is now abutting the chorion Fetus demonstrates a skeletal body Fluid is displayed in fetal sto
Twelfth Gestational week sono findings
By ____ w, the neural plate has developed
4.5
What structure forms the CNS
Neural Plate
Plate gives rise to the neural tube which becomes
spine and brain
Prosencephalon(forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
3 Primary vesicles of brain
Number of cranial bones connected by sutures
8
Seen as hypo spaces b/t bone
sutures
Premature fusion of sutures
craniosyntosis
Spaces between the fetal bones are termed
fontanelles
Anterior fontanelle when filled with bone is
bregma
Posterior fontanelle when filled with bone is
lambda
opening in the base of the skull which the spinal cord travels
Foramen magnum
Largest part of brain
cerebrum
Cerebral lobes
6 frontal 2 temporal 2 parietal occipital
Cerebrum is divided into rt and lt hemispheres by
interhemispheric fissure
Falx cerebriis located within
interhemispheric fissure
Cerebral hemispheres are linked in the midline by the
corpus callosum
a thick band of tissue that provides communication between the rt and lt hemispheres
corpus callosum
3 meninges cover and protect brain and spinal
Pia mater-innermost
Arachnoid membrane-middle layer
Dura mater- dense outermost layer
Should be completely intact between 18 and 20 weeks
corpus callosum
4 parts of corpus callosum ant to post
Rostrum,genu,body and splenium respectively
Forms at the same time as the cavum septum pellucidum
corpus callosum
Normally when the corpus callosum is absent, the ___ is absent also
CSP
Does not communicate with the ventricular system
CSP
The closure of this structure is normal in later gestation and often occurs before birth or shortly thereafter
CSP
The 2 lobes are located on both sides of the third ventricle
Thalamus
The ____ adhesion passes through the third ventricle to connect the two lobes of the thalamus
massa intermedia or interthalamic adhesion
Ventricular system function
provide cushion for brain
Ventricular system is Lined by a membrane called the
ependyma
mass of cells responsible for producing the cerebrospinal fluid in the fetus
Choroid plexus
Each lateral ventricle communicates with the third ventricle at the
foramen of Monroe
The third ventricle connects to the fourth ventricle by means of a long, tubelike structure called
aqueduct of Sylvius
What is located anterior the the cerebellum within the midline of the brain
Fourth ventricle
The fourth ventricle has 3 openings through which the CSF travels. 2 openings allow CSO to ______. The other allows CSP to pass from ______ to _____ and ______.
subarachnoid space
fourth ventricle to cisterna magna and subarachnoid space
Arachnoid villi are responsible for the
reabsorption of CSF into the venous system
Located in the posterior fossa of the cranium
CM
Appears as an anechoic, fluid filled space, posterior to the cerebellum, between the cerebellar vermis and the interior surface of the occipital bone
CM
Located in the posterior fossa of the cranium along w/ CM
Cerebellum
Consists of two hemispheres, right and left, joined together at the midline by the cerebellar vermis
Cerebellum
The cerebellar tonsils are located on the undersurface of the cerebellum and become distorted with what malformation
spina bifida and Arnold-Chiari malformations
The lateral ventricle does not typically measure more than ____ mm at the level of the atrium
10
Cerebellum grows at a rate of
1 mm per week between 14 and 21 weeks
