Embryology Flashcards
Alar Plate
Dorsal, Sensory
Basal Plate
Ventral, Motor
Notochord
Nucleus Pulposus and IV disc in adults, Induces overlying ectoderm to differentiate into neuroectoderm and formneural plate
Neural Plate
Neural Tube and Neural Crest Cells
Prosencephalon
Forebrain, makes up the telencephalon and diencephalon
Telencephalon
Cerebral hemispheres and lateral ventricles
Diencephalon
Thalamus and third ventricle
Mesencephalon
Midbrain, aqueduct
Rhombencephalon
hindbrain, splits into metencephalon & myelencephalon
Metencephalon
Pons and cerebellum
upper part of 4th ventricle
Myelencephalon
medulla, lower part of 4th ventricle
Neuroectoderm
CNS neurons, ependymal cells, oligodendroglia, astrocytes
Neural Crest
PNS neurons, Schwann cells
Mesoderm
Microglia
Neural Tube Defects
elevated AFP in amniotic fluid and maternal serum, increased AChE in amniotic fluid
Failure of bony spinal canal to close but no structural herniation. Tuft of hair or skin dimple at level of bony defect
Spina bifida occulta
Meninges, not spinal cord, herniate through spinal canal defect (normal AFP)
Meningocele
Meninges and spinal cord herniate through spinal canal defect
Meningomyelocele
Malformation of anterior neural tube resulting in no forebrain, polyhydraminos
Anencephaly
Frog-like appearance
Anencephaly
Failure of left and right brain hemispheres to separate
Holoprosencephaly
Mutations in sonic hedgehog signaling pathway
Holoprosencephaly
herniation of cerebellar tonsils and vermis through foramen magnum
Arnold Chiari Malformation II
Aqueductal stenosis and hydrocephalus, often presents with lumbosacral myelomeningocele and paralysis below the defect
Arnold Chiari Malformation II
Agenesis of cerebellar vermis with cystic enlargment of 4th ventricle
Dandy-Walker
Enlarged posterior fossa
Dandy-Walker
Cystic cavity (syrinx) within the spinal cord
Syringomyelia
“cape-like” BL loss of pain and temperature sensation in upper extremities; Anterior Spinal Commissural fibers
Syringomyelia
Most commen syrinx location
C8-T1
Syringomyelia is associated with
Chiari I malformation
Sensation of Anterior 2/3 of tongue
CN V3
Taste sensation of Anterior 2/3 of tongue
CN VII
Taste and Sensation of Posterior 1/3 of Tongue
CN IX
Taste in the extreme posterior tongue
CN X
Occipital Myotomes
where muscles of tongue are derived from
Arches for Anterior 2/3 tongue
Arches 1 & 2
Arches for Posterior 1/3 tongue
Arches 3 & 4
Multinucleated giant cells in the CNS
HIV-infected microglia
Injured in MS, PML and leukodystrophies
Oligodendroglia
Promote axonal regeneration
Schwann Cells
BL Acoustic neuroma
Neurofibromatosis type 2
Meissner Corpuscles
Large, myelinated fibers; adapt quickly in Glabrous (hairless) skin
Sensory Corpuscles Dynamic, fine/light touch; position sense
Meissner Corpuscles
Sensory Corpuscles Vibration and pressure
Pacinian corpuscles
Sensory Corpuscles Found in deep skin layers, ligaments, and joints
Pacinian Corpuscles
Sensory Corpuscles In basal epidermal layer, hair follicles
Merkel Discs
Sensory Corpuscles Pressure, deep static touch, position sense
Merkel Discs
Invests single nerve fiber layers
Endoneurium
Surrounds a fascicle of nerve fibers.
Perineurium
Dense CT that surrounds entire nerve
Epineurium