2. Review of Cellular Neuroanatomy Flashcards
Parts of Neuron and Function (3)
- Cell Body(Soma)-metabolic supply
- Single Axon-output for electrical impulses
- Dendrites(including spines)-receive input
Gray vs. White Matter
Gray-unmyelinated, primarily somas and dendrites
White-myelinated axons
Nissl Stain
Stains “Nissl Substance” made up of basophilic “Nissl Bodies” (rER/ribosomes) in neuronal somas and proximal dendrites
Pyramidal Neuron
pear-shaped soma and prominent apical dendrite with a group of basal dendrites
Are there organelles at the axon hillock?
NO
What is between the axon hillock and the beginning of myelination and why is it important?
Axonal Initial Segment. Site of AP generation
Branches of the axon are called?
Collaterals
Buzzwords: Unipolar Pseudounipolar Bipolar Multipolar
Not in humans
Sensory in DRG
Local Circuit Neurons
Motor, pyramidal, purkinje
Projection Neuron
integrate info and send axons to other brain areas
- Golgi Type I
- ie. Principal Cells(pyramidal neuron)
Interneuron
don’t send axon out of local brain area(local circuit)
- Golgi Type II
- ie. Chandlier, basket and double bouquet cells
Electrical vs Chemical Synapse
Electrical-direct connection via gap junctions (6 connexion= 1 connexon; 2 connexons= gap jcn)
Chemical-unidirectional, neurotransmitters released after Ca influx, postsynaptic receptors
Name 5 neuronal synapses based on subcellular target
Axosomatic
Axodendritic
-Axospinous
Axoaxonic
DendrodendriticExcitatory Neurotransmitters
Glutamate at AMPA and NMDA receptors
Ach at nicotinic
Inhibitory Neurotransmitters
Glycine
GABA at GABA-A
Modulatory Neurotransmitters
Dopamine NE ACh at muscarinic GABA at GABA-B Serotonin
Excitatory Synapse
Gray’s Type 1
Asymmetric(pronounced postsynaptic density)
Found on Dendrites
Inhibitory Synapse
Gray’s Type 2
Symmetric density
Found on Soma
How do things move down axon. Anterograde? Retrograde?
Microtubules. Kinesin(antero). Dynein(retro)
Supporting Cells and buzzwords (6)
Schwann Cells-myelin PNS; forms 1 internode
Oligodendrocytes-myelin CNS; 1 for 30-50 axons
Astrocytes-Fibrous and Protoplasmic; metabolic
Microglia-Mac of CNS
Satellite Cells-astrocytes in ANS; neural crest
Ependymal Cells-line ventricles; cuboid/columnar
Node of Ranvier
Unmyelinated area where APs regenerate
Schmidt-Landerman Clefts/Incisures
Small folds of cytosol remaining in the Schwann Cell after wrapping around the axon
Endoneurium vs Perieurium
Endo-Thin layer of CT surrounding each nerve fiber
Peri-surrounds the fasicle
