Brain Embryology

Question 1

The neural plate is induced due to signals from what structure?

Answer 1

the notochord

Question 2

What section of neural tube will develop into the brain?

Answer 2

cranial to 4th somite

Question 3

What are the names of the primary brain vesicles?

Answer 3

Prosencephalon, Mesencephalon, and Rhombencephalon

Question 4

As the neural tube folds ventrally into a C shape, what are the names and locations of the ventral flexures that develop?

Answer 4

cephalic flexure- between the forebrain and midbrain
cervical flexure- between hindbrain and spinal cord

Question 5

During week 5, the prosencephalon develops into which subdivisions?

Answer 5

the telencephalon and diencephalon

Question 6

During week 5, the rhombencephalon develops into which subdivisions?

Answer 6

the metencephalon and myelencephalon

Question 7

Unequal growth between flexures results in a dorsal flexure. What is its name and location?

Answer 7

the Pontine flexure; between the mesencephalon and metencephalon (developing pons)

Question 8

What is the adult derivative of the telencephalon?

Answer 8

the cerebral hemispheres

Question 9

What is the adult derivative of the diencephalon?

Answer 9

the optic cup/nerves, thalamus, and hypothalamus

Question 10

What is the adult derivative of the mesencephalon?

Answer 10

the midbrain

Question 11

What is the adult derivative of the metencephalon?

Answer 11

the cerebellum and pons

Question 12

what is the adult derivative of the myelencephalon?

Answer 12

the medulla oblongata

Question 13

From which part of the fetal devleoping brain do the lateral ventricles develop?

Answer 13

telencephalon (prosencephalon)

Question 14

From which part of the fetal devleoping brain does the majority of the 3rd ventricle develop?

Answer 14

diencephalon (prosencephalon)

Question 15

What brain cavity develops from the mesencephalon?

Answer 15

the aqueduct

Question 16

The metencephalon and myelencephalon are responsible for the development of which brain cavity?

Answer 16

the 4th ventricle

Question 17

What is the function of ependymal cells?

Answer 17

To line the cerebral ventricles and help secrete CSF

Question 18

ependymal cells would be expected to have a high level of which type of junction?

Answer 18

tight junctions (adherens may also be highly present)

Question 19

What two enzymes are especially necessary for CSF production?

Answer 19

Na+/K+ ATPase and Carbonic anhydrase

Question 20

In the development of the Choroid Plexus, which structure is responsible for first invaginating into the ventricle roof?

Answer 20

developing arteries

Question 21

As the primitive choroid plexus enlarges, what main histological development occurs?

Answer 21

the apperance of villi with brush border of microvilli, which can secrete CSF

Question 22

After CSF is produced, it traverses what in order to enter the subarachnoid space?

Answer 22

the median and lateral aperatures

Question 23

CSF is absorbed into the dural venous sinuses through what mechanism?

Answer 23

absorption through the arachnoid villi (granulations)

Question 24

What characterizes the condition of Hydrocephalus?

Answer 24

an imbalance between production and absorption of CSF, resulting in too much CSF

Question 25

Which layer of the neural tube contributes to choroid plexus and produces CSF?

Answer 25

the ependymal layer

Question 26

Which layer of the neural tube involves cell proliferation?

Answer 26

the ventricular zone

Question 27

Cells from the mantle layer of the neural tube have what purpose?

Answer 27

to migrate and form GRAY matter of CNS

Question 28

Cells from the marginal layer of the neural tube have what purpose?

Answer 28

axons of mantle layer cells form WHITE matter of CNS

Question 29

The mantle zones are dervied from what structure of the neural plate?

Answer 29

the alar (dorsal) and basal (ventral) plates

Question 30

the caudal myelencephalon (medulla) will housewhich cranial nerve nuceli?

Answer 30

CN III-XI

Question 31

the medulla oblongata has what 3 major functions?

Answer 31

regulation of respiration, heartbeat, and reflexes

Question 32

the alar plate in the caudal myelencephalon migrates and forms what type of neurons in 3 columns?

Answer 32

sensory afferent neurons

Question 33

the basal plate in the caudal myelencephalon forms what type of neurons in 3 columns?

Answer 33

motor neurons

Question 34

Cerebellar malformations often result in what clinical finding?

Answer 34

ataxia (lack of muscle coordination/control)

Question 35

What is a Chiari malformation?

Answer 35

A structural defect with a projection of cerebral tissue through the formane magnum

Question 36

As the mesencephalon develops, alar plate cells migrate ventrally to form what significant structure?

Answer 36

the substantia nigra

Question 37

the choroid pleus develops in what generalo region of the neural tube?

Answer 37

the roof plate

Question 38

Rostral to the pontine flexure, the rhombic lip expands over to neural canal to give rise to what?

Answer 38

the cerebellum

Question 39

The walls of the diencephalon are formed by cells from exclusively which plate?

Answer 39

the alar plate

Question 40

What is Lissencephaly?

Answer 40

A lack of normal cortical layers, due to incomplete migration of cortical neurons

Question 41

What differences in brain matter caused by lissencephaly are visible in CT scan?

Answer 41

the brain would appear smooth

Question 42

What is microcephaly?

Answer 42

a reduced brain size, due to fewer than normal neurons produced

Question 43

Infection with zika virus (ZIKV) during pregnancy increases risk for what neurological condition for the fetus?

Answer 43

microcephaly, due to insufficient neurons to populate the cortical plate

Question 44

In what ventricle are the lateral foramina of Luschka and the medial foramen of Magendie located?

Answer 44

the fourth ventricle

Question 45

Which section of the adult brain is know as the cardiorespiratory regulation center?

Answer 45

the medulla oblongata

Question 46

In which secondary brain vesicle does the third ventricle develop?

Answer 46

the diencephalon

Question 47

What are clinical findings associated with lissencephaly?

Answer 47

severe psychomotor retardation, unusual facial appearance, muscle spasms, failure to thrive

Question 48

What are clinical findings associated with chiari malformation?

Answer 48

occipital headache, neck pain, and cerebellar symptoms (i.e. ataxia); these can appear in adolescence/early adulthood

Question 49

What are clinical findings associated with hydrocephalus?

Answer 49

typical findings of increased ICP (headache, nausea, vomiting, abnormal gait, impaired consciousness)