Cells Of The Nervous System Flashcards
Describe the structure of a nerve?
Endoneurium = connective tissue surrounding axons
Bundle of axons = fascicle
Perineurium = surrounds each fascicle
Exoneurium = surrounds fascicles, fat, blood vessels
What is the difference between a dendrite and an axon?
Dendrites = impulse form one neural cell to soma of another
Many dendrites per cell
Decrease in diameter further from soma
Dendritic spines
Axons = impulse away from soma
One per cell
Constant diameter
Many intermediate filaments and microtubules
What are the 2 types of axon terminals and where are they found?
Bouton
Varicosities = smooth muscles, pne axon makes whole muscle contract
Describe the cytoskeleton of neuronal cells
A lot of intermediate filaments and microtubules
Highly organised = tensile strength
Neuronal filaments = scaffolding of axons
Describe movement of substances in neuronal cells
Vesicles = fast anterograde transport (towards synapse) using microtubules - unidirectional
Retrograde movement = substances are structurally different to vesicles so they dont get confused
Types of synapses?
Axo-dendritic = excitatory Axo-somatic = inhibitory Axo-axonic = modulatory
How wide is a synapse?
20-100 nm
Classifications of neurones
Pseudo unipolar = sensory
Bipolar cells = retinal
Golgi type 1 multipolar= long axon e.g. motor
Golgi type 2 multipolar =short axon
Classes of neuralgia in CNS?
Astroglia
Microglia
Ependymal
Oligodendritic
Classes of neurolgia in PNS
Schwann cells
Satellite cells
What are astrocytes and their functions?
Intermediate filaments = glial fibrillation acidic protein 2 types - fibrous and protoplasmic FUNCTION: Potassium ion buffering Macrophage Axon growth Homeostasis of NT
What are microglia?
Macrophages of the CNS Smallest cells 3 types: Resting ratified Rod like Activated
What are ependymal cells?
Line the fluid filled ventricles
Produce CSF
What are satellite cells?
In the PNS
Each neuronal cell is surrounded by satellite cell to help with its function
Which cells produce myelin in the CNS and PNS
CNS = oligodendrocyte PNS = Schwann
What are oligodendrocytes?
2 types = inerfasicular (in rows), perineural (with soma)
NO INTERMEDIATE FILAMENTS
Can produce myelin for multiple cells
