Development Of The Nervous System Flashcards
This process occurs during the 3rd week of embryogenesis, and is when the 3 layers of embryonic tissue are formed.
Gastrulation
Name the 3 different structures that are involved in the development of the nervous system:
The notochord - forms 1st
The neural tube - gives rise to CNS
The neural crest - gives rise to PNS
The CNS develops from the primitive (ecto/endo/meso)derm?
Ectoderm
The first step of neural system development is the formation of the ______ _____.
Neural plate
During the ______ week of development, the anterior neuropore closes, 3 primary brain vesicles are formed dividing the brain into: (name 3)
4th
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
During the ____ week, the 3 primary brain vesicles divide into 5 secondary brain vesicles, 2 additional flexures appear, and the optic cup and nerves bulge from the diencephalon to form the eye.
5th
Anterior horn motor neurons innervate skeletal muscle and are classified as _______ _______.
The lateral horn motor neurons project to autonomic ganglia and are classified as _______ ________.
Somatic efferent (SE)
Visceral efferent (VE)
_______ neurons whose peripheral processes innervate the skin and receptors in joint capsules, tendons, and muscles are classified as somatic afferent (SA).
Sensory
The intervertebral foramina, containing the spinal nerves, move caudally; and nerves from lumbar, sacral, and coccygeal levels are lengthened to form a bundle called the _____ ______.
Cauda equina
_______ are paired blocks of paraxial mesoderm.
Somites
The sensory neurons of dorsal root ganglia are derived from the ______ _____.
Neural crest
The segmental nature of the embryo is reflected in the segmental sensory innervation of the body surface. These segments are known as __________.
Dermatomes
___________- failure of the anterior neuropore closure. Results in no brain formation, death is inevitable.
Anencephaly
____________-failure of the back of the skull to close.
Cranioshisis
The cystic structure contains meninges:_____________
Meninges plus brain:__________________
Meninges plus brain and a part of the ventricular system:________________
Meningocele
Meningoencephalocele
Meningohydroencephalocele
This type of defect involves herniation of the cerebellar vermis and tonsils through the foramen magnum. Often associated with a cavitation of the spinal cord or of the medulla.
Chiari 1 malformation
This type of defect is also called the Arnold-Chiari malformation and is associated with myelomeningocele.
The Chiari 2 malformation
Myeloschisis - defect in the closure of the _________ neuropore.
Posterior (spina bifida)
