Nervous System Flashcards
Define:
- Ganglion
- Nerve
- Neuropil
ganglion - collection of PNS neurons
nerve - bundle of axons
neuropil - surrounding stain in material
What are the three types of neurons?
Unipolar - 1 process
Bipolar - 2 processes
Multipolar - more than 2
What is the most common neuron? least common?
Most common - multipolar
least common - bipolar
What are the structures of a neuron?
Dendrites Soma Axon Nissle bodies Synapse
What is the dendritic spine?
specialized synaptic contact areas in some dendrites
The nucleus of a neuron stains ____ while the nucleolus stains ____
nucleus - light
nucleolus - dark
The nissle bodies of neurons contain
RER / ribosomes
What is the postsynaptic density?
specialized underlying plasma membrane that holds receptors in place
______ are myelin cells in the CNS while _____ and myelin cells in the PNS
Oligodendrocytes - CNS myelin cell
Schwann cell - PNS myelin cell
Neuromuscular junction / motor end plates contain _______ to increase surface area of muscle
junctional folds
What are the different types of synapses?
Axosomatic - axon on cell body
Axoaxonic - Axon A on dendrite. Axon B on axon A
Axodendritic - Axon on dendrite. MOST COMMON
Axospinous - axon on dendritic spin
Neurotransmitters are released by ____
exocytosis
What are Low MW transmitters?
small non-peptide molecules
synthesized in terminal
What do these Low MW transmitters do? Acetylcholine dopamine serotonin glutamate gamma-amino-butyric acid
acetylcholine - NM junctions
dopamine - neuromodulator in horizontal / amacrine
serotonin - CNS and photoreceptors
glutamate - inhibitory (main one for photoreceptor)
GAB - in horizontal / amacrine cells
What are High MW transmitters?
peptide
synthesized in soma
Anterograde goes from ___ to ____
Retrograde goes from ___ to ___
anterograde - soma to terminal
retrograde - terminal to soma
What are the PNS glial cells?
Schwann cells - myelinated
Satellite cells - environment control
What are the CNS glial cells?
Oligodendrocytes - myelinated
Astrocytes - around neurons
Microglia - injury reponse
Ependymal cells - line ventricles of brain / SC
Mueller cells extend from ____ to ____
ILM to ELM
Astrocytes are the ___ size and are important for the
largest
blood-brain barrier
Microglia are the ___ size and respond to ___
smallest
respond to injury
Ependymal cells contain ____, synthesize ___, and are known as ____ in the ventricles of brain
cilia
CSF
Tanycytes
What is Multiple Sclerosis?
demyelination of motor neurons
What is Lateral Sclerosis?
Degeneration of motor neurons
Loss of axons in corticospinal tracts
What is Alzheimer’s?
Senile dementia
loss of neurons in cortex
due to build up of protein “plaques” and neuronal tangles
What is the difference between gray matter and white matter?
gray matter - cell bodies
white matter - axons and dendrites
the posterior horn of the spinal cord is ____ while the ventral horn is ____
posterior horn - sensory
ventral horn - motor
What is the difference between the endoneurium, perineurium and epineurium?
endoneurium - surrounds 1 axon
perineurium - surrounds 1 fascicle
epineurium - surrounds 1 nerve
What are the three layers of the meninges?
dura mater
arachnoid mater
pia mater
What meningeal space contains CSF and vessels?
subarachnoid
What holds the arachnoid to the pia?
arachnoid trabeculae
What is the blood-brain barrier? What is the only molecule allowed through?
Perivascular space in the brain surround by BM from endothelium and end feet of astrocytes
Only glucose allowed through
CSF is produced by the _____ of the _____ and is continuous with the _____ of the spinal cord
choroid plexus of ventricle
continuous with central canal of spine
What does the optic nerve exit though in the orbit?
lamina cribosa
What are the retinal layers starting inner and moving outwards
ILM ON layer Ganglion layer Inner plexiform layer Inner nuclear layer outer plexiform layer outer nuclear layer inner / outer segments of photoreceptors RPE
What is drusen?
partially digested materials in Bruch’s membrane
The spherule of a rod makes synaptic contact with __ bipolar cell and __ horizontal cells
1 bipolar cell
2 horizontal cells
The pedicle of a cone makes synaptic contact with __ bipolar cell and __ horizontal cells
2 bipolar cells
2 horizontal cells
Bipolar cells are the direct route to _____ cells
ganglion
Amacrine cells connect multiple ____ cells to ____ cells.
Horizontal cells connect multiple ___ cells to ____ cells
amacrine - multiple bipolar to ganglion
horizontal - multiple PRs to bipolar
where is the highest rod density?
20 degrees from fovea
The optic disc is elongated more ___ than ___
more vertically than horizontally
What is the physiologic cup?
optic disc indentation
The optic disc lacks al layers except ___ and ___
fibers and ILM
Why is the optic disc pale?
No RPE
What are the three fibers types of ganglion cells?
Arcuate fibers - arch around macula
Radiating fibers - go directly to disc
Papillomacular bundle - macula to disc
What are the layers of the macula lutea?
Foveola
Fovea
Parafovea
Perifovea
What is the clivus?
sloped wall ending in foveola
Where is the Far Peripheral Retina?
at ora serrata
What is the retinal blood supply?
outer layer - choroidal capillaries
inner retina - central retinal artery
What is meningitis?
infection of the meninges leading to inflammation
What are the four sources of vessels to the optic nerve?
- branches from CRA
- Branches from circle of Zinn
- Choroidal branches
- Pial branches
