Neurons and Microglia Flashcards
what are the 4 cytoskeleton components of neurons
fibrillar proteins
microtubules
microfilaments
neurofilaments
what are nissl bodies
RNA in free ribosomes and rER
where are nissl bodies found
everywhere except axon hillock and axon
what is the function of nissl bodies
protein synthesis
what are the 4 types of synapses
axodendritic
axodendritic with dendritic spine
electrical
dendrodendtitic
what is neuropil
synapse region with glial processes, dendrites, and unmyelinated axons
what is the structure of a gap junction
6 molecules of connexin make up a hemichannel
2 hemochannels (one from each opposing membrane makes up a gap junction
what is the arrangement of neurofilaments
3x2
what is the function of microtubules (2)
fast anterograde axonal transport
axon regrowth
in what diseases do neurofilaments become tangled up
Alzheimers
Lou Gehrig’s
Charcot Marie Tooth
what is the function of microfilament
motility of growth cone during development
what are the functions of dendrites (2)
increase SA for signal reception
integrate signals
what is the function of dendritic spines
enhance synaptic surface area
what is the plasma membrane of the axon called
axolemma
which is fast/slow/both:
anterograde axon transport
retrograde axon transport
anterograde- fast and slow
retrograde- fast
fast, retrograde axonal transport uses what motor protein
dynein
fast, anterograde axonal transport uses what motor protein
kinesin
what gets transported fast retrograde
vesicle membrane remnants
reuptaken neurochemicals
nerve growth factors
cholera toxin
bacteria/viruses
what gets transported fast anterograde
pre-propeptides
enzymes required for processing of neuropeptides
what gets transported with slow anterograde axonal transport
neurofilaments
microtubules
enzymes required for small molecule neurotransmitter synthesis
what are 2 locations where multipolar neurons are located
ventral horn of spinal cord
pyramidal cells of layer V
where are bipolar neurons located (3)
retinal neurons
olfactory neurons
cochlear/vestibular ganglia
where are pseudo-unipolar neurons found
dorsal root ganglion cells
sensory ganglion of CN V, VII, VIII, and X
what neuron structure type is formed from bipolar neurons
pseudo-unipolar
where are unipolar neurons found
sensory cells of cochlea
vestibular ganglion cells
how are golgi type 1 and type 2 projection types different
type 1- principle and projecting neurons with long axons
type 2- intrinsic neurons with short axons acting locally
are interneurons golgi type 1 or 2
2
what are spindle neuons
large neurons with fat, elongated soma with few dendrites
in what regions of the brain are spindle neurons found
anterior cingulate cortex
fronto-insular cortex
dorsolateral prefrontal cortex
___ neurons are though to be the first among neurons damaged in diseases like Alzheimers and frontotemporal dementia
specialized spindle
what are the connective coverings in the peripheral NS
epineurium
perineurium
endoneurium
what are the connective coverings in the central NS
only endoneurium
the neocortex has 2 broad categories of neurons; __ and __
pyramidal and non-pyramidal
what neurotransmitter do pyramidal cells release
glutamate
do pyramidal cells release an excitatory or inhibitory neurotransmitter
excitatory (glutamate)
how do pyramidal and non-pyramidal cells of the neocortex differ in their projection location
pyramidal project to other cortical areas or out of the cortex
non-pyramidal do not project outside the neocortex
non-pyramidal cells of the neocortex release what neurotransmitter
GABA
do non-pyramidal cells of the neocortex release an excitatory or inhibitory neurotransmitter
inhibitory
large diameter pyramidal cells in the M1 (motor cortex), layer 5 region are called __
Betz cells
what are the 5 classes of neuroglia
astrocytes
oligodendrocytes
radial glia
microglia
ependymal cells
what is the function of protoplasmic astrocytes (2)
metabolic function to facilitate exchange of nutrients between blood vessels and neurons
provide limiting membrane on blood vessels and pia
what is the function of fibrous aatrocytes
form scar tissue
in white matter, oligodendrocytes are called __
in grey matter, oligodendrocytes are called __
white- interfascicular
grey- perineural
what are radial glia cells
progenitors of neurons, astrocytes, and oligodendrocytes
*they degenerate once the cerebral cortex is developed
what is the function of radial glia cells
act as a scaffold for migration of cortical cells
what is the function of mircroglia
phagocytosis
what are the 3 types of ependymal cells
ependymocytes
tanycytes
choroidal epithelial cells
what is the main function f ependymocytes
produce CSF
what is the main function of choroidal epithelial cells
form tight junctions
line choroid plexus of ventricles
production and secretion of CSF
absorption of CSF
what cells are the site of the blood-CSF barrier
choroidal epithelial cells
the choroid plexus is the site of the ___
blood CSF barrier
the blood CSF is made of __ cells
the blood brain barrier is made of __ cell
endo or epithelial cells
blood CSF= epithelial
blood brain= endothelial
what cells help form the blood brain barrier
astrocytes
how does myelin production differ in the CNS and PNS
CNS- oligodendrocytes produce myelin that covers up to 60 neurons
PNS- Schwann cells produce myelin that covers one neurons
what are the symptoms of Guillian Barre syndrome (4)
ascending muscle weakness
loss of proprioception
areflexia
deep aching muscle pain
Guillian Barre syndrome can be caused by a descending version. This version is called ___
Miller Fisher Syndrome
what are the symptoms of Charcot Marie Tooth disease
ascending muscle weakness in foot and lower limbs (can lead to hammertoes, footdrop, etc.)
neuropathic pain, numbness/tingling
what is the cause of symptoms in multiple sclerosis
damaged nerve myelination
what is primary active MS
increasing disability
attack episodes
gets worse between attack episodes
what is primary not active MS
steady increase in disability
no attacks
what is relapsing remitting MS
increasing disability
attacks
does not get worse between attacks
*most common progression type
what are the 2 main treatments for MS
interferons
glatiramer acetate
what is being looked for in brain scan to diagnose MS
demyelinating brain lesion in optic nerve (left)
demyelinating plaques (Dawson Fingers) near ventricles and around occipital lobe (right)
how does diabetes lead to diabetic polyneuropathy
minimal circulation to hands/feet–>hypoxia –>degeneration of nerves–>polyneuropathy
what is neurofibromatosis
tumor of neural tissue (glia or neurons)
how does type I neurofibromatosis differ from type II
I- tumors of neural tissue in the brain, spinal cord, and peripheral tissue
II- acoustic neuroma of CN VIII–>deafness
what type of neuronal damage is reversible
mitochondria swelling
ER
cellular swelling
what type of neuronal damage is irreversible
Ca2+ deposits in the mitochondria
cytomembrane ruptures
what type of neuronal damage leads to cell death
pyknosis (nucleus shrinks)
karyorrhexis (nucleus falls apart, becomes eccentric)
karyolysis (nucleus disappears)
