1- development of nervous system

Question 1

why does the Caudia equine form

Answer 1

• the lumbar spine grows faster than the spinal cord

- the lower cord is stretched drawing out into the caudia equina

Question 2

why do neural tube defects predispose to hydrocephalus

Answer 2

• cord is tethered at site of defect
• as spine grows cord cannot move within vertebral canal, causing brainstem to be pulled down through foramen magnum and become occluded

Question 3

craniorachischisis

Answer 3

neural tube remains open,brain and spinal cord don’t form. incompatible with life

Question 4

anecephaly

Answer 4

cranial neural tube fails to close. failure of brain to form. may live for a little

Question 5

myelocoele

Answer 5

spinal cord does not develop, csf filled cyst. have neurological defects and have meningitis often

Question 6

which 3 defects have abnormal neural tube

Answer 6

• craniorachischisis
• anecephaly
• myelocoele

Question 7

which defects have normal neural tube

Answer 7

• myelomeningocoele
• meningocoele
• spina bifida occulta

Question 8

myelomeningocoele

Answer 8

CSF filled cyst containing spinal cord. does not transilluminate. neurological defect

Question 9

meningocoele

Answer 9

CFS filled cyst. transilluminates. no neurological defect

Question 10

spina bifida occulta

Answer 10

lack of posterior vertebral arch, tuft of hair/naevus over deficit. no neurological problems.

Question 11

how does folic acid work

Answer 11

fusion of epithelial cells, not fully known

Question 12

di George syndrome

Answer 12

• immunodeficiency
• facial anomalies
• heart anomalies
• hypocalcaemia

Question 13

hirschprungs disease

Answer 13

lack of enteric neurones in large intestine. hypo mobility, constipation