Neuron Structure Flashcards
3 parts of neuronal cytoskeleton?
Microtubules
Neural filaments
Microfilaments
Microtubule structure/location?
Tubulin diners arranged into hollow tube
Large
Run down neurites
Function of microtubules
How are they made and regulated?
Transport (esp down axon where there is no ER (transport organelle))
Microtubule associated proteins
Neurofilament structure?
Medium
Functions of neurofilaments?
Structural support
Regulate diameter of axons
Structure of microfilaments
Small
Actin
Function of microfilaments
Connects with pm and microtubules
What are neurites
Dendrites + axon
Where do densrities receive chemical info
Synapses on dendritic spines
What protein is abundant in dendrites?
Actin
How can environment and development affect dendritic spines
Affect length and density
Eg. Longer but fewer in mentally retarded individuals
3 parts of axon?
Axon hillock
Axon proper
Axon terminal
2 types of axon transport?
Fast and slow exoplasmix transport
Describe fast exoplasmix transport
1m a day
Anterograde: kinesin takes proteins to the axon terminal (via microtubule)
Retrograde: dynein takes metabolites away from axon terminal
Describe slow exoplasmix transport
Mechanism unknown
0.1-10mm
3 features of axon terminals?
No microtubules
Lots of vesicles
Lots of membrane proteins, hence mitochondria
Synapses consist of
Presynaptic axon terminal
Synaptic cleft
Postsynaptic neuron
5 variations in neuron structure?
- length of axon
- neurotransmitter
- number of axons
- shape
- connections
Describe variation in neuronal connections
Can be with other neurons, the environment or effectors
Variation in neuron shape?
Pyramidal - linear, transmit info
Stellate - collect info
Describe variation in number of axons
- unipolar: soma connected to one axon
- bipolar
- multipolar
Role of myelinating glia
Schwann cells and oligodendrocytes - create myelin, increasing conduction velocity…
Functions of microglia?
Brain immune system
Gifts neural inflammation
Macrophages phagocytise stuff
Role of ependymal cells?
Epithelial
Line ventricles
Secrete CSF
FORM choroid plexus which kinds lateral ventricle
Role of astrocytes?
Contributes to blood brain barrier
Processes hold oresynaptic and postsynaptix neurons together - take up ions, release modulators
K+ bufferingg
