CNS Flashcards
singular meninx is composed of
specialized epithelial cells (meningothelial cells)
meninges are supported by
connective tissue
meninges have a — function
protection
the meninges are confined to
outlet layer of brain and cord in CNS
dura mater
outermost layer
thick layer of dense connective tissue, internally lined by mesothelium
dura in the cranium
fuses with the periosteum of the skull
dura in the spinal cord
dura surrounded by epidural space
subdural space
separates the dura from underlying arachnoid mater
underlying subarachnoid space is lined by
flattened mesothelial cells
subarachnoid space separates the arachnoid from the Pia mater, subarachnoid space contains
CSF
subarachnoid space is continuous with
ventricles of the brain
pia mater is highy
vascular
pia + arachnoid
leptomeninges
denticulate ligamanets
support cord, extend from pia, anchor cord to arachnoids, dura, and periosteum
neurons in the CNS are derived from
neuroectodermal cells of the neural tube
brain and cord contain
gray and white matter
peripheral gray matter contains
neuron cell bodies, dendrites, and axons
central white matter contains
mostly myelinated axons
neuroglia/neuroglial cells
large number of support cells in the CNS
neuroglia are highlight branched and provide
structural and metabolic support for neurons
aid in tissue repair following injury
oligodendrocytes
CNS equivalent of Schwann cells, elaborate myelin sheaths
astrocytes
most highly branched, largest neuroglia cells
microglia
phagocytic, fixed tissue macrophage; part of monocyte-macrophage lineage; smallest neuroglia cells; originally mesodermal, have immune function
ependymal cells
cuboidal epithelium singing ventricles and central canal of spinal cord
ependymal cells are frequently
ciliated, microvilli for reabsorption of CSF
CSF is secreted by the
choroid plexus
choroid plexus
vascular structure arising from walls fo ventricle in brain
modified — cells secrete CSF
ependymal cells of the choroid plexus
cerebrum is also known as the
cerebral cortex
in mammals, neocortex evolved to include
sensory, motor, and association areas
in humans –% of the cortex is neocortex
90%
cerebrum is grossly organized into
folds or gyri
cerebral cortex is composed of — — peripherally
gray matter
nuclei
Clusters of neuron cell bodies form small islands of gray matter in cerebrum & cerebellum
Neuroglial cells in gray matter include (2)
astrocytes and microglial cells
Deep to cortex is subcortical
white matter (medulla)
white matter contains mostly
myelinated axons surrounded by oligodendrocytes
Axons leading in & out of gray matter also grouped in bundles called
tracts
Histologically, neurons of neocortex divided into — morphological categories
five
Anatomically, divided into —layers, designated with Roman numerals I-VI, from superficial to deep
six
functionally, arranged into
vertical columns or units
cortical neurons (5)
pyramidal cells stellate cells cells of martinotti fusiform cells horizontal cells of cajal
pyramidal cells
pyramid-shaped neurons with long, slender axons, varying in size from small to large
Beta cells
largest pyramidal cells, include upper Moto neurons in the motor cortex
stellate cells
mall star-shaped neurons with short axons & dendrites
cells of martinotti
small neurons with long, horizontal axons
fusiform cells
vertically oriented, spindle-shaped neurons with vertical axons
horizontal cells of cajal
horizontally oriented, spindle-shaped neurons with horizontal axons