Module 1: Basic tissue types: Nervous Flashcards
CNS consists of
brain and spinal cord
integrates sensory info received and initiates and coordinates responses to stimuli
Grey and white matter
grey matter
almost all of the neron cell bodies and their associated fibers as well as a bast number of neruoglia
white matter
tracts of nerve fibers as well as some neuroglia
consisting of mainly oligodendrocytes (responsible for myelination)
meninges
outer surface of the brain and spinal cord is covered by 3 specialized connective tissue layers, collectively known as the meninges
cerebral cortex
opposite arrangement of grey and white matter tot hat of the spinal cord
grey matter forms outer cerebral cortex (6 layers)
white matter consists of a mass of fibre tracts in the central core
cerebellum
pink staining medullary core of white matter
blue staining covering of grey matter made up of 3 layers
neurons of the grey matters outermost (molecular) layer and inner (granular) layer are relatively small
Purkinje cells found between granular and molecular layers (large multipolar neurons unique to the cerebellum)
spinal cord
central butterfly-shaped region of grey matter, in the middle of which is located the central canal
White matter is located outside the grey matter (where myelinated tracts of nerve fibers ascend and descend); main bodies of this area are the neuroglial oligodendrycytes
PNS
an extension of the CNS
consists of extensions of brain and spine, the cranial and spinal nerves and nodules of associated neuronal cell bodies (ganglia)
divisions of PNS
autonomic nervous system: involuntary functions
somatic nervous system: voluntary
cell bodies of all neurons are located in the
CNS with exception of cell bodies of most primary sensory neurons and the terminal effector neurons of the autonomic nervous system
nervous tissue cells
impulses of info from neurons spread to other neurons (via synapses in neural pathway)
impulses sent may trigger or inhibit the spread of info (excitatory or inhibitory)
Interneurons or association neurons that coordinate all of the info spread throughout body segments
non dividing, respond to stimuli
nerve impulse
waves of excitation generated by nerve cell membranes
neurons
large cell body with nucleus, surrounded by cytoplasm (which is perikaryon)
a single axon and one or more dendrites
dendrites
highly branched
either end in specialized sensory receptors or form synapses
axon hillock
cone shaped portion of cell body that axon arises from
terminal boutons
swollen ending of small branches from axon?
axons are commonly referred to as
nerve fibres
multipolar neuron
most common
many dendrites projecting from cell body
bipolar neuron
single dendrite that arises from the pole of the cell body opposite to the origin of the axon
act as receptor neurons for smell, sight, blanace
pseudo-unipolar neuron
single dendrite and axon arise from a common sten of the cell body
Nissl substance
clumps of highly basophilic cytoplasmic material called Nissl substance/bodies
Represents rough endoplasmic reticulum where protein synthesis takes place
found in perikaryon and dendrites but not present in axon or axon hillock
lack of nissl substance
indicates neuron damage
Neuroglia
support cells: astrocytes oligodendrocytes microglias ependymal
Astrocytes
star shaped
most numerous glial cells in grey matter
perivascular feet
