Nervous System Organization and Development

Question 1

What structures of the peripheral nervous system derived from Neural tube?, and the others ones where do they come from?

Answer 1

• preganglionic axons of skeletal motor neurons
• preganglionic axons of the autonomic neurons
• others ones: Neural crest cells

Question 2

Signs in a pregnant woman of anencephaly and causes

Answer 2

• polyhidramnios, increase alfa-fetoprotein (AFP) and acetylcholinesterase (AChE)
• defect of closure in the rostral neuropore (day 25)

Question 3

What causes the defect in closure of caudal neuropore or to induce bone growth around it?, what day should it close?

Answer 3

• Spina bifida; meningocele and myelomeningocele increase alfa-fetoprotein (AFP); myeloschisis increase AFP and acetylcholinesterase (AChE)
• Day 27

Question 4

In what case do you expect to find low and high levels of Alfa-fetoprotein (AFP)?

Answer 4

• Down syndrome - low level

- Onphalocele and gastroschisis - high level

Question 5

What malformation consist in cerebellar vermis and medulla downward displacement through foramen magnum leading in obstruction of IV ventricle?, what other signs can you see?

Answer 5

• Arnold-chiari malformation type II

- hydrocephaly, accompanied by meningomyelocele frequently

Question 6

What does the arnold-chiari malformation type I consist? and what other malformation usually is associated?

Answer 6

• cerebellar tonsils displacement through foramen magnum

- syringomyelia

Question 7

Failure of foramina of Lushka and Magendie to open leading dilation in IV ventricle. What other findings would you expect in this malformation?

Answer 7

• Dandy-walker malformation

- agenesis pf cerebellar vermis and splenium of corpus callosum

Question 8

Incomplete separation of cerebral hemispheres, what genetic defect commonly associates with it?

Answer 8

• holoprosencephaly

- trisomy 13 (Patau syndrome)

Question 9

What structure is damaged or injured in central horner syndrome?

Answer 9

Descending hypothalamic fibers - drive all preganglionic sympathetic neurons

Question 10

what structures at the head innervates the sympathetic nervous system?, how do the sympathetic fibers arrive there?

Answer 10

• dilator pupillae muscle, sweat glands, superior tarsal muscle
• through periarterial carotid nerve plexus

Question 11

Which cranial nerves carry parasympathetic fibers, and the name for each ganglia used?

Answer 11

• III: ciliarry ganglion - pupillary sphincter ciliary muscle
• VII: *submandibular ganglion - submandibular and sublingual glands
• pterygopalatine ganglion - lacrimal, nasal and oral mucosal glands
• IX: otic ganglion - parotid gland
• X: terminal ganglia (various) - viscera of thorax and abdomen (foregut and midgut)