1.2 embryology

Question 1

define gastrulation

Answer 1

outer layer of bilaminar disc invaginates at primitive streak to form trilaminar disc

Question 2

what does diencephalon become?

Answer 2

thalamus, hypothalamus, optic nerve, retina

Question 3

hydrocephalus

Answer 3

cord tethered aster site of defect, brainstem pulled down through foramen magnum = occlusion

Question 4

craniorachischisis

Answer 4

entire neural tube open, brain and spinal cord don’t form

incompatible with life

Question 5

myelocoele

Answer 5

spinal cord doesn’t develop, neural tube exposed to outside world

and CSF cyst

neurological deficit, prone to meningitis

Question 6

myelomeningocoele

Answer 6

CSF cyst containing spinal cord, but spinal cord and roots stretched so neurological deficit possible

Question 7

meningocele

Answer 7

CSF cyst, cord in vertebral canal

may predispose to infection though

Question 8

spina bifida oculta

Answer 8

lack of posterior vertebral arch, tuft of hair over region on back

common

Question 9

problems associated with di George syndrome

Answer 9

immunodeficiency
facial anomalies
heart anomalies
hypocalcaemia

Question 10

why does hirschprungs disease lead to comstipation

Answer 10

no enteric neurons in parts of large intestine, so peristalsis slow so hypo motility