Trans - Neurohistology Flashcards
2 main types of cells in neural tissue
- neurons
2. neuroglia
appearance of neuron under microscope
dark staining cytoplasm, pale staining nucleus with prominent nucleolus, prominent Golgi complex
central region in the cytoplasm surrounding the nucleus
perikaryon
Nissl bodies - define
clumps of basophilic material in the perikaryon
dendrite - function
receive input
axon - function
transmit output
differentiate dendrite and axon
dendrites are short, numerous and branched
axons are long, single, and unbranched
cortical extension of the soma into the axon
axon hillock
end of the axon
terminal bouton
rope-like intertwining component of cytoskeleton
microfilament
component of cytoskeleton resembling a spiderweb
intermediate filaments
what are the most prominent components of the cytoskeleton
microtubules
microtubules - function
transport of vesicles from golgi body to terminal bouton
organelle movement
what produces the myelin sheath in the CNS
oligodendrocytes
what produces the myelin sheath in the PNS
schwann cells
myelin sheaths are better observed using:
osmium fixation
unipolar neurons - appearance
one axon, no dendrites
unipolar neurons - where are they found
embryonic CNS
pseudo unipolar neurons - appearance
dendrites branch friom the axon
pseudo unipolar neurons - examples
sensory neurons
what type of neuron is the most susceptible to injury
pseudo unipolar neuron
bipolar neuron - appearance
2 processes on opposite ends of the soma - axon on one side, dendrites on the other
bipolar neuron - examples
neurons which transmit special senses (retina, olfactory, etc)
multipolar neuron - appearance
many cytoplasmic processes, only one axon
multipolar neuron - examples
pyramidal cells, purkinjie cells
2 types of multipolar neuron
- Golgi type 1
2. Golgi type 2
what type of neuron is the most common (structure-wise)
multipolar neurons
Golgi type 2 - appearance
have locally projecting axons (remain in grey matter of cerebrum)
Golgi type 1 - appearance
have long projecting axons (ex. pyramidal cells)
what type of neuron is the most common (function-wise)
interneurons
layers of the cerebral cortex
- molecular layer
- external granular
- external pyramidal
- internal granular
- internal pyramidal
- multiform layer
molecular layer - characteristics
no neuron soma - dendrites and axons only
external granular layer - characteristics
with small pyramidal neurons
shape of granular neurons
stellate
external pyramidal layer - characteristics
with small-medium pyramidal neurons
what layer is the main source of cortical-cortical efferent fibers of the motor system
external pyramidal layer
internal granular layer - characteristics
with stellate and pyramidal neurons
what layer is the main target for thalamocortical afferent fibers
internal granular
line of Gennari - what lobe
occipital
line of Gennari - what layer
internal granular (4th)
internal pyramidal layer - characteristics
with large pyramidal neurons
example of large pyramidal neuron
Betz cells
what layer is the principal source of subcortical efferent fibers and the corticospinal tract
internal pyramidal
what layer is responsible for the reciprocal connections to and from the thalamus
multiform
multiform layer - characteristics
with large pyramidal neurons, spindle like neurons, multiform neurons
how can astrocytes be seen more clearly (stain)
Glial Fibrillary Acidic Protein (GFAP) stain
fibrous astrocyte - function
sends foot processes involed in BBB
protoplasmic astrocytes - function
processes envelop synapses for nutrition, regulation, and support
differentiate astrocyte from neuron under the microscope
astrocyte has dark staining nucleus
oligodendroglia - function
myelination
approx. how many axons does an oligodendrocyte myelinate
50
microglia - function
phagocytic cells of CNS - engulf pathogens and foreign material, clean up remnants of physiological cell death
ependymal cells - shape
cuboidal
ependymal cells - function
lining of ventricles and CSF canals, involved in movement of CSF
[T/F] ependymal cells are ciliated
T
number of layers in hippocampus
3
which layers are in hippocampus
- molecular
- granular
- pyramidal
number of layers in cerebellum
3
what layers are in cerebellum
- molecular
- Purkinjie
- granular
approx how many axons does a Schwann cell myelinate
1
Schwann cell - function
myelination of axons
repair of damaged axons
what is the neuropil
neurons and neuroglia
appearance of oligodendrocytes under microscope
fried eggs
cells in anterior horn of spinal cord
large pyramidal neurons
cells in white matter of spinal cord (other than neurons)
oligodendrocytes