Brain Embryology Flashcards
The neural plate is induced due to signals from what structure?
the notochord
What section of neural tube will develop into the brain?
cranial to 4th somite
What are the names of the primary brain vesicles?
Prosencephalon, Mesencephalon, and Rhombencephalon
As the neural tube folds ventrally into a C shape, what are the names and locations of the ventral flexures that develop?
cephalic flexure- between the forebrain and midbrain
cervical flexure- between hindbrain and spinal cord
During week 5, the prosencephalon develops into which subdivisions?
the telencephalon and diencephalon
During week 5, the rhombencephalon develops into which subdivisions?
the metencephalon and myelencephalon
Unequal growth between flexures results in a dorsal flexure. What is its name and location?
the Pontine flexure; between the mesencephalon and metencephalon (developing pons)
What is the adult derivative of the telencephalon?
the cerebral hemispheres
What is the adult derivative of the diencephalon?
the optic cup/nerves, thalamus, and hypothalamus
What is the adult derivative of the mesencephalon?
the midbrain
What is the adult derivative of the metencephalon?
the cerebellum and pons
what is the adult derivative of the myelencephalon?
the medulla oblongata
From which part of the fetal devleoping brain do the lateral ventricles develop?
telencephalon (prosencephalon)
From which part of the fetal devleoping brain does the majority of the 3rd ventricle develop?
diencephalon (prosencephalon)
What brain cavity develops from the mesencephalon?
the aqueduct
The metencephalon and myelencephalon are responsible for the development of which brain cavity?
the 4th ventricle
What is the function of ependymal cells?
To line the cerebral ventricles and help secrete CSF
ependymal cells would be expected to have a high level of which type of junction?
tight junctions (adherens may also be highly present)
What two enzymes are especially necessary for CSF production?
Na+/K+ ATPase and Carbonic anhydrase
In the development of the Choroid Plexus, which structure is responsible for first invaginating into the ventricle roof?
developing arteries
As the primitive choroid plexus enlarges, what main histological development occurs?
the apperance of villi with brush border of microvilli, which can secrete CSF
After CSF is produced, it traverses what in order to enter the subarachnoid space?
the median and lateral aperatures
CSF is absorbed into the dural venous sinuses through what mechanism?
absorption through the arachnoid villi (granulations)
What characterizes the condition of Hydrocephalus?
an imbalance between production and absorption of CSF, resulting in too much CSF
Which layer of the neural tube contributes to choroid plexus and produces CSF?
the ependymal layer
Which layer of the neural tube involves cell proliferation?
the ventricular zone
Cells from the mantle layer of the neural tube have what purpose?
to migrate and form GRAY matter of CNS
Cells from the marginal layer of the neural tube have what purpose?
axons of mantle layer cells form WHITE matter of CNS
The mantle zones are dervied from what structure of the neural plate?
the alar (dorsal) and basal (ventral) plates
the caudal myelencephalon (medulla) will housewhich cranial nerve nuceli?
CN III-XI
the medulla oblongata has what 3 major functions?
regulation of respiration, heartbeat, and reflexes
the alar plate in the caudal myelencephalon migrates and forms what type of neurons in 3 columns?
sensory afferent neurons
the basal plate in the caudal myelencephalon forms what type of neurons in 3 columns?
motor neurons
Cerebellar malformations often result in what clinical finding?
ataxia (lack of muscle coordination/control)
What is a Chiari malformation?
A structural defect with a projection of cerebral tissue through the formane magnum
As the mesencephalon develops, alar plate cells migrate ventrally to form what significant structure?
the substantia nigra
the choroid pleus develops in what generalo region of the neural tube?
the roof plate
Rostral to the pontine flexure, the rhombic lip expands over to neural canal to give rise to what?
the cerebellum
The walls of the diencephalon are formed by cells from exclusively which plate?
the alar plate
What is Lissencephaly?
A lack of normal cortical layers, due to incomplete migration of cortical neurons
What differences in brain matter caused by lissencephaly are visible in CT scan?
the brain would appear smooth
What is microcephaly?
a reduced brain size, due to fewer than normal neurons produced
Infection with zika virus (ZIKV) during pregnancy increases risk for what neurological condition for the fetus?
microcephaly, due to insufficient neurons to populate the cortical plate
In what ventricle are the lateral foramina of Luschka and the medial foramen of Magendie located?
the fourth ventricle
Which section of the adult brain is know as the cardiorespiratory regulation center?
the medulla oblongata
In which secondary brain vesicle does the third ventricle develop?
the diencephalon
What are clinical findings associated with lissencephaly?
severe psychomotor retardation, unusual facial appearance, muscle spasms, failure to thrive
What are clinical findings associated with chiari malformation?
occipital headache, neck pain, and cerebellar symptoms (i.e. ataxia); these can appear in adolescence/early adulthood
What are clinical findings associated with hydrocephalus?
typical findings of increased ICP (headache, nausea, vomiting, abnormal gait, impaired consciousness)
