Lecture 4: Development of the Periphery (unfinished)

Question 1

After the fusion fo the neural folds, what happens to neural crest cells?

Answer 1

They leave the dorsal aspect of the developing neural tube.

Question 2

Neural cells migrate away from..?

Answer 2

the neural tube

Question 3

cells form the nerual crest differentiate into what?

Answer 3

into a variety of neural and non-neural cell types.

Question 4

neural crest stem cells can become?

Answer 4

BDNF - sensory neurones
BMP - autonomic neurone 
Endothelin 3 - pigment cell
neurkgulin - Schwann cells
TGFB - smooth muscle

Question 5

Presumptive sympathetic ganglion neurons migrate from ?

Answer 5

the developing neural crest and neural tube.

Question 6

Presumptive sympathetic ganglion neurons form what and when?

Answer 6

They form 2 chains of sympathetic ganglia at 5 weeks.

Question 7

where do neuroblasts migrate from?

Answer 7

migrate from the thoracic portion

Question 8

what do neuroblasts supply?

Answer 8

supply structures in the head and neck and caudally to innervate structures in the lower body.

Question 9

what do some neuroblasts form?

Answer 9

prevertabral ganglions or organ plexuses.

Question 10

Spinal nerve fibers grow to innervate the ?

Answer 10

sympathetic ganglia

Question 11

sympathetic ganglionic neuroblasts extend what to what/

Answer 11

extend fibres to their target organs.

Question 12

Sympathetic plexuses are found where?

Answer 12

heart and lungs

Question 13

where do Pre-ganglionic parasympathetic neurons project from ?

Answer 13

they project from the mesencephalon, rhombencephalon and sacral region of the spinal cord.

Question 14

Pre-ganglionic parasympathetic neurons send axons along what?

Answer 14

They send axons along the paths of the cranial and somatic nerves.

Question 15

what does the parasympathetic NS not contain?

Answer 15

chains of ganglia

Question 16

ganglia arising from the PNS are generally ?

Answer 16

terminal or intramural.

Question 17

The ENS forms from neural crest arising from ?

Answer 17

the rhomencephalon (vagal) and sacral regions of the spinal cord.

Question 18

Ablation of the vagal section of the neural crest prevents formation of what?

Answer 18

enteric ganglia in the oesophagus, stomach, small and large intestine.

Question 19

Ablation of the sacral section of the neural crest prevents formation of ?

Answer 19

enteric ganglia in the large intestine.

Question 20

what’s a placode?

Answer 20

thickened patches of ectoderm that develop primarily into special sensory structures.

Question 21

where do places derive from?

Answer 21

They are derived from a ectoderm around the neural plate

Question 22

what are the 5 main placodes?

Answer 22

olfactory placode
optic placode
Adenohypophyseal placode 
otic placode
Profundal/trigeminal placodes

Question 23

what does the olfactory placode form?

Answer 23

the nasal olfactory epithelium

Question 24

where does the optic placode lie?

Answer 24

lies on the surface, adjacent to the optic vesicle (which forms the retina) and form the lens.

Question 25

what does the Adenohypophyseal placode give rise too?

Answer 25

– gives rise to cells of the pituitary (non neuronal).

Question 26

what placode forms the inner ears?

Answer 26

Otic placodes

Question 27

what is the first placode visible on the surface of the embryo?

Answer 27

Otic placodes

Question 28

Profundal/trigeminal placodes contribute to what?

Answer 28

contribute cutaneous sensory neurons in mammals.

Question 29

what does Epibrachail give rise too?

Answer 29

distal portion of facial ganglia.