Von Bartheld Development Flashcards
the CNS appears in the (blank) week of human development.
3rd week
Explain early brain development
neural plate (thickening of ectoderm) occurs due to notochord signals-> neural plate folds inward making neural groove-> neural tube-> fusion starts central of tube and moves cranial and caudally. -> neuropores created-> closure of neural tube-> spinal cord and wide cephalic portion with several dilations (brain vesicles)
failure of the neural tube to close results in….?
neural tube defects (can involve vertebrae, muscles and skin)
what do you call a neural tube defect that occurs in the spinal cord
spina bifida
What do you call a neural tube defect that occurs at the cephalic end?
anencephaly (forebrain doesnt form)
When the flow of CSF is obstructed CSF will accumuate and will result in (blank)
hydrocephalus
What do you call a neural tube defect when the meninges protrude?
meningomyelocele
What do you call a neural tube defect when the meninges protrude and the nervous system protrudes?
meningoencephalocele
During neuralation (neural tube formation) another impotant structure forms at the “crest” (upper portion) of the neural tube called the (blank)
neural crest
Cells of the neural crest subsequently migrate along distinct paths and give rise to a variety of structures in the body, including (blank) and (Blank).
sensory and sympathetic ganglia
Most nerve cells derive from what?
the nerual tube or the neural crest
Is the retina part of the PNS or CNS?
CNS
At 4-6 weeks what happens to the brain?
you get subdivision
What are the subdivisions of the brain that occur at 4-6 weeks of development?
prosencephalon (telencephalon + diencephalon)
mesencephalon (midbrain)
rhombencephalon (metencephalon and myelencephalon)
What is the mesencephalon?
the midbrain
What is the metencephalon?
pons and cerebellum
What is the myelencephalon?
medulla
The neural tube becomes patterened along the longitudinal axis into (blank) which have specific sets of (blank) that regulate the segmental development in the embryo.
neuromeres
homeobox genes
What happens if you have a mutation in a homeobox gene?
disease like aniridia and waardenburg syndrome (craniofacial defects, spina bifida and hearing loss)
The develops from (blank) compnents that make the lens and (blank) components that make the retina
placodes
neural tube
At 22 days of development what happens to the eye?
optic vesicles form and induce lens placode in ectoderm, then optic vesicle invaginates and forms optic cup
What does the inner surface of the optic vesicle form?
the choroid fissure and hyaloid artery,
Please describe inner ear development
at 22 days->otic placode (level of rhombencephalon) invaginates and forms otic vesicle (otocyst). Otic vesicle makes the membranous labyrinth.
The otic placode, together with neural crest, also give rise to the (blank) and (blank) ganglia
auditory and vestibular
What are the components of the membranous labyrinth?
saccule, cochlear duct, utricle, semicircular canals, endolymphatic duct
Rubella virus or toxoplasmmosis in the first trimester may cause severe damage to (blank)
the organ of corti
The olfactory placode gives rise to what? How often are these replaced?
olfactory receptor cellsevery 6-8 weeks
Some cells within the region of the olfactory placode migrate into (blank)
CNS and become part of the hypothalamus.
The pituitary develops from 2 different parts, what are they?
an outpocketing of the oral cavity -> rathkes pouch
and
a downward extension of the diencephalon-> infundibulum
Does rathkes pouch stay connected to the oral cavity through development?
no
What does rathkes become in the hypothalamus?
forms anterior lobe of the hypophysis or adenohypophysis.
What does the infundibulum become in the hypothalamjus?
stalk, pars nervosa (posterior lobe of hypophysis)
(blank) can rise from remnants of Rathkes pouch, causing hydrocephalus and pituitary dysfunction
craniopharyngiomas
When do spinal nerves pass through the intervertebral foramina at the level of their orign?
as an embryo
Where does the spinal cord end?
L2-3
What do nerve fibers form below L2-3?
the cauda equina
Where should you do a lumbar puncture?
below L2-L3 to avoid the spinal cord
What does neuraltion require from the notocord? Name a few please
signals :)
noggin and chordin
What does noggin and chordin do?
it inhibits BMP so that neuralation can occur
What is an agent that is well known but can interfere with neuraltion?
vitamin A (retinoic acid)