Neuro Flashcards
(349 cards)
Neural Development
Notochord induce ectoderm to differentiated –> neuroectoderm –> neural plate –> neural tube and NCC
Notochord becomes nucleus pulpsus
Alar plate (dorsal)- sensory, regulated by TGFB (BMP)
Basal plate (ventral: motor, regulated by SHH
Prosencephalon
Telencephalon –> cerebral hemispheres and basal ganglia (walls) and lateral ventricles (cavities)
Diencephalon –> Thalamus, hypothalamus, retina (walls) and third ventricle (cavity)
Mesencephalon
Midbrain (walls) Cerebral aqueduct (cavities)
Rhomboencephalon
Metencephalon –> pons and cerebellum (walls) and upper part of fourth ventricle (cavity)
Myelencephalon –> medulla (walls) and lower part of fourth ventricle (cavity)
CNS origin
Neuroepithelia in neural tube –> CNS, ependymal cells, oligodendrocytes, astrocytes
PNS origin
NCC –> PNS, Schwann cells, glia, melanocytes, adrenal medulla
Microglia origin
Mesoderm
Neural tube defects
Neuropores fail to fuse (4th week) –> persistent connection between amniotic cavity and spinal canal
Associated with maternal DM and low folate
High AFP and acetylcholinesterase
Spinal bifida occulta
Failure of causal neuropore to close, but no herniation
seen at lower vertebral levels
Dura intact
Associated tuft of hair or skin dimple at level of bony defect
Meningocele
Meninges herniate through bony defect
Myelomeningocele
Meninges and neural tissue herniate through bony defect
Myeloschisis
Exposed, unfused neural tissue without skin covering
Anencephaly
failure of rostral neuropore to close –> no forebrain, open calvarium
polyhydramnios
Holoprosencephaly
Failure of embryonic forebrain to separate into 2 cerebral hemispheres (weeks 5-6)
Mutations in SHH
Associated with other midline defects (cleft lip, cyclopia)
increased risk of pituitary dysfunction
Associated with Patau
Lissencephaly
failure of neuronal migration resulting in smooth brain that lacks sulci and gyri
associated with microcephaly, ventriculomegaly
Chiari I malformation
Ectopia of cerebellar tonsils inferior to foramen magnum
Congenital, asymptomatic in children
Adult- HA, cerebella symptoms
Associated with syringomyelia
Chiari II malformations
Herniation of cerebellar vermis and tonsils through foramen magnum with aqueductal stenosis –> noncommunicating hydrocephalus
Associated with lumbosacral myelomeningocele
MORE SEVERE
presents earlier in life
Dandy Walker malformation
agenesis of cerebellar vermis –> cystic enlargement of 4th ventricle that fills the enlarged posterior fossa
Associated with noncommunicating hydrocephalus, spina bifida.
Syringomyelia
Cystic cavity within central canal of spinal cord
Fibers crossing in anterior white commissure damaged first
cape like bilateral symmetrical loss of pain and temperature sensation of UE
Associated with Chiari I and scoliosis
Tongue Development
1st and 2nd pharyngeal arches for anterior 2/3 (CNV3 and CN VII)
3rd and 4th pharyngeal arches form posterior 1/3 (CNIX and CNX)
motor innervation via CNXII to hyoglossus, genioglossus and styloglossus
Motor innervation via CNX to palatoglossus
Neurons
Signal tranmission
Permanent- do not divide in adults
Neuron markers: neurofilament proteins, synaptophysin
Astrocytes
common glial cell type in CNS Physical support, repair, extracelluar K buffer, remove excess NT BBB Derived from neuroectoderm Marker: GFAP
Microglia
Phagocyte cells of CNS
mesoderm
Not stained via Nissl
HIV infected –> dementia
Ependymal cells
ciliated columnar glial cells line ventricles and central canal of spinal cord
Apical surfaces are covered in cilia and microvilli
Choroid plexus –> produce CSF