Embryology

Question 1

Meroencephaly (anencephaly)

Answer 1

Failure of the anterior neuropore to close

Question 2

Spina bifida cystica

Answer 2

failure of the posterior neuropore to close

Question 3

Lissencephaly

Answer 3

abnormal patterning of sulci and gyri. Incomplete neuronal migration to the cerebral cortex during the 3rd and 4th months of gestation.

Question 4

Grey matter heterotopia

Answer 4

gray matter appears in white matter, basis for seizure disorder

Question 5

Neurocristopathies

Answer 5

neuroblastoma, Schwannoma, Neurofibromatosis, Waardenburg syndrome, pheochromocytoma, Hirschsprung’s disease, CHARGE, DiGeorge syndrome

Question 6

Neuroblastoma

Answer 6

neuroendocrine tumor arising from any neural crest cell element of the sympathetic nervous system. Metastasizes widely in bone marrow, bones and lymph nodes.

Question 7

Raccoon eyes

Answer 7

appear with neuroblastoma and metastasis of neuroblastoma to the skull

Question 8

Schwannoma

Answer 8

benign tumor of Schwann cells of neural crest origin. It is most commonly located near the vestibular branch of CN VIII

Question 9

Neurofibromatosis/Von Recklinghausen Disease

Answer 9

NF Type 1 is an autosomal dominant condition characterized by changes in skin pigmentation and tumors along nerves in skin, brain and other parts of the body

Question 10

Cafe au lait spot

Answer 10

clinically associated with neurofibromatosis. Flat patch on skin that are darker than the surrounding area.

Question 11

Pheocromocytoma

Answer 11

tumor in adrenal medulla. Occurs as a result of too much epinephrine and norepinephrine

Question 12

Waardenburg syndrome

Answer 12

genetic condition that causes congenital hearing loss and changes in pigmentation of hair, skin, and eyes.

Question 13

NTDs

Answer 13

caused by abnormal neurulation

Question 14

Total Dysraphism

Answer 14

incomplete closure of the neural tube

Question 15

Anencephaly

Answer 15

total dysraphism of the brain with normal function of the spinal cord

Question 16

Spina Bifida Aperta/Myeloschisis

Answer 16

entire spinal cord is open to the body surface, bifid vertebral spines are also present

Question 17

Localized spinal dysraphism

Answer 17

only certain regions of the neural tube remain open

Question 18

Meningomyelocele

Answer 18

most common open NTD. Type of spina bifida in which the neural tube and its meningeal membranes protrude from the vertebral canal, forming a fluid filled sac. Aka spina bifida cystica

Question 19

Risk factors for meningomeyloceles

Answer 19

valproic acid, vitamin A, hyperthermia, maternal diabetes

Question 20

Meningocele

Answer 20

meningeal membrane protrudes into the sac but the spinal cord does not. Less severe than meningomyelocele

Question 21

Spina bifida oculta

Answer 21

NTD at the level of the spinal cord. Caused by failure of the posterior neuropore to close. Often location is mid sacral and marked externally by tuft of hair, mole, angioma, lipoma, or dimple. May be associated with tethered cord

Question 22

Encephaloceles

Answer 22

NTD at level of brain. Brain tissue protrudes through the skull. Most common location is occipital but can also be frontal.

Question 23

Tethered spinal cord

Answer 23

lower end of spinal cord is attached in a lower than normal position. Filum terminal is short an thick.

Question 24

Chiari malformation

Answer 24

4 types. Most common congenital anomaly that involves structural defect of cerebellum. Cerebellum is located below the foramen magnum.

Question 25

Hydrocephalus

Answer 25

3rd and lateral ventricles are swollen with fluid, cerebral cortex is abnormally thin, and surfers of skull are forced apart

Question 26

Obstructive/noncommunicating hydrocephalus

Answer 26

caused by lack of communication between ventricles and subarachnoid space. Commonly caused by congenital aqueduct stenosis or choroid plexus tumors that secrete too much CSF.

Question 27

non obstructive or communicating hydrocephalus

Answer 27

free communication between the ventricles and the subarachnoid space but the reabsorption of the CSF is impaired. Common cause–> obliteration of the subarachnoid cisterns and malfunction of arachnoid villi

Question 28

Holoprosencephaly

Answer 28

results from incomplete separation of the cerebral hemispheres and most are associated with facial abnormalities.

Question 29

Dandy walker anomaly

Answer 29

complete agencies of the cerebellar vermis and cystic dilation of the fourth ventricle that occupies the posterior fossa.

Question 30

Agenesis of Corpus Callosum

Answer 30

complete or partial absence of corpus callosum

Question 31

Derivatives of neural crest cells

Answer 31

Dorsal root ganglia, majority of ANS

Question 32

Derivatives of neural tube in PNS

Answer 32

All preganglionic autonomic fibers and somatic motor fibers

Question 33

Mesoderm derivatives of PNS

Answer 33

Dura mater and connective tissue investments of peripheral nerve fibers

Question 34

What separates the pharyngeal arches externally?

Answer 34

Ectoderm-lined pharyngeal clefts

Question 35

What separates the pharyngeal arches internally?

Answer 35

Endoderm-lined pharyngeal pouches.

Question 36

What does each pharyngeal arch contain?

Answer 36

Outer ectoderm, inner endoderm and a core of mesenchyme

Question 37

Nerve of First (mandibular) pharyngeal arch

Answer 37

Trigeminal

Question 38

Nerve of second (hyoid) pharyngeal arch

Answer 38

Facial

Question 39

Nerve of third pharyngeal arch

Answer 39

Glossopharyngeal

Question 40

Nerve of fourth pharyngeal arch

Answer 40

Superior laryngeal nerve of vagus

Question 41

Nerve of sixth pharyngeal arch

Answer 41

Recurrent laryngeal branch of vagus

Question 42

Groove between the maxillary prominence and the lateral nasal prominence

Answer 42

Nasolacrimal groove (cleft).

Question 43

Primary (anterior) palate

Answer 43

formed by merging of the medial nasal prominences

Question 44

Secondary (posterior) palate

Answer 44

formed by fusion of the palatine shelves (plates and processes)