Development of the Nervous System Flashcards
Above the 4th somite:
At and below the 4th somite:
Brain
Spinal cord
Anatomy of the spinal cord (gray matter)
Posterior (sensory), Lateral (autonomic), Anterior (motor) horns.
Anatomy of the spinal cord (white matter)
Posterior (sensory), Lateral (autonomic), Anterior (motor) funniculi.
Lateral horn is only located:
From T1 - L2.
Alar plate
Will become sensory portion.
Basal plate
Will become motor portion.
Sulcans limitans
Will separate alar and basal plates.
Embryonic cells of Ventricular, Intermediate (Mantle), Marginal Zones
VZ: ependymal and choroid plexus cells.
IZ: gray matter. Neurons and astrocytes.
MZ: white matter. Myelinated axons.
Neural tube gives rise to neuroectoderm which gives rise to:
Neurons, astrocytes, oligodendrocytes, choroid plexus.
Microglial cells come from:
Mesoderm
Where does the newborn’s spinal cord end?
L2-L3
SC grows much slower than VC.
High BMP causes:
Dorsal differentiation (alar plate). Comes from the roof plate. Sensory. PAX3 and PAX7 genes are activated.
High SHH causes:
Ventral differentiation (basal plate). Comes from notochord and floor plate. Motor. NKX 2.2 and NKX 6.1 are activated.
What cell types form the PNS?
Neural crest and ectodermal placode.
Motor neurons and preganglionic autonomic neurons come from:
Neural tube cells
Neurons from dorsal root ganglia, Schwann cells, and SNS and PSNS ganglia come from:
Neural crest
CNS is myelinated by:
Oligodenrocytes and occurs from 6 mo. to puberty.
PNS is myelinated by:
Schwann cells. Occurs prior to 4 mo. Motor roots before sensory.
Dorsal (posterior) root
Sensory. From neural crest.
Ventral (anterior) root
Motor. From neuroectoderm.
Spinal nerves
Mixed sensory and motor nerves.
Dorsal ramus
Mixed. Motor to dorsal muscles and sensory to dorsal integument.
Ventral ramus
Mixed. Motor to limbs lateral and ventral to body wall. Sensory to to integument of same region.
Rami are the:
Communication centers.
GSE
Motor to somatic muscle.
GVE
Autonomics to smooth and cardiac and glands.
SVE
Motor to muscles from pharyngeal arches.
GSA
From neural crest. Sensory to skin, joint capsules, tendons and muscles.
GVA
Sensory of visceral structures.
SSA
Hearing, balance, sight.
SVA
Taste and smell.
Efferent neurons are from:
Afferent neurons are from:
Neuroectoderm
Neural crest
Ganglion and postganglionic neurons are from:
Neural crest.
Preganglionic neurson are from:
Neuroectoderm.
Sympathetic region of spine
Thoracolumbar T1 - L2.
Sympathetic neurons have:
Short and myelinated preganglionic neurons. Long and unmyelinated postganglionic neurons.
Parasympathetic neurons have:
Long and myelinated preganglionic neurons. Short and unmyelinated postganglionic neurons.
Parasympathetic regions of spine
Cranial and sacral regions.