Spinal cord development Flashcards
Spinal cord
part of CNS that arises from brainstem and ends at the conus medullaris
3 primary functions of spinal cord
carry motor signals from brain to PNS
carry sensory info from PNS to brain
coordinate reflexes
ectoderm
outmost of the 3 primary germ layers. the root of all neural tissue
mesoderm
muddle of the 3 primary germ layers. form much of the bone and musculature
endoderm
innermost of the 3 primary germ layers. forms much of the viscera
neurulation
the process of neural tube formation
neural tube
the precursor structure to the CNS
neuropores
the openings found at each end of the neural tube
neural tube formation occurs
between day 16-28 after conception
day 15 neural tube formation
neural plate forms, neural groove begins
day 18 neural tube formation
neural plate begins to fold centrally
day 20 neural tube formation
first neural tube fusion occurs
day 20-22 neural tube formation
neural tube slow fuses outward from the center
day 22-24 neural tube formation
anterior (cranial) neuropore closes
day 26-28 neural tube formation
posterior (spinal) neuropore closes
day 28+ neural tube formation
neural tubes closed. will begin to differentiate into structures
DNA is rapidly duplicating during neural tube formation which means —-
increased folate requirement
what is the blueprint for folding
DNA
What is affected in all forms of spina bifida
somites
What do somites form
the mesoderm
differentiate to form skin, muscles, and axial skeleton
notochord goes on to form
intervertebral discs
neural crest cels differentiate to form
the Pia and arachnoid mater
When should the spinal cord end
L1 or L2; conus medullaris
2 most common neural tube defects
spina bifida
ancephaly
neural tube defects
any of a series of conditions caused by failure of the neural tube to close
open neural tube defect
neural tube defect with meninges/neural tissue exposed
closed neural tube defect
neural tube defect with skin intact
Occulta spina bifida
most common and least debilitating
technically falls under closed NTD category but might not involve neural tube at all
Meningocele spina bifida
out pouching of meningeal layers without neural tissue
Myelomeningocele
out pouching of meningeal layers with neural tissue
Myeloschisis
outpouring of neural tissue without meningeal covering
What is unaffected by the supplementation of folate
lipomyelomeningocele
so folate deficiency does not increase risk of lipomyelomeningocele
spinal cord imaging is complete primarily via
MRI with or without contrast
MRI works by
measuring energy released by protons in the body tissue
CT measure _____, MRI measures ______
CT measures density
MRI measures RF signal from protons
MRI contrast dye
Gadolinium
T1 spinal MRI
CSF = dark
Gray matter = gray
White matter = white
T2 spinal MRI
CSF = bright
Gray matter = gray
white matter = dark
Flair spinal MRI (T2 with inverted CSF)
CSF = dark
Gray matter = gray
White matter = dark
STIR spinal MRI uses
beneficial for fat suppression
water (edema) = bright
FLAIR MRI uses
suppresses fluid (CSF) allowing for increased visibility near CSF-brain borders
What is CT myelogram good for
CSF leak
