Flashcards in Cellular Neuroanatomy (1) Deck (65)
2 principal cell types in nervous system
Neurons and glia
Structural and functional unit of the NS
3 functions of glia
1. Physical support ( protection)
2. Electrical insulation
3. Metabolic exchange b/n vascular system and NS
Function of neuronal cell body. Other name?
Produces proteins and provides metabolic function. Also called soma
Which neuronal structures receive input from other neurons.
What kind of inputs are are preferentially on to dendrites and dendritic spines?
Excitatory synaptic inputs
What three functions do dendritic spines serve as the anatomical substrate for?
1. Synaptic transmission
2. Synaptic plasticity
3. Memory storage
How many axons does each neuron have? Function?
One and ONLY ONE axon. Axons conduct electrical output from one neuron to another.
How many dendritic spines may be on a dendrite?
Hundreds to thousands. Remember they are the small membranous protrusions from the dendrites themselves, sort of like microvilli.
Soma of neurons is esp. rich in what organelle?
What are Nissl bodies?
Basophilic masses consisting primarily of rough ER and ribosomes. Function is protein synthesis.
Positive Nissl stain indicates what 2 neuronal structures.
1. Cell bodies
2. Proximal dendrites
Where is Nissl substance not found in neurons?
In the axon, beginning at the axonal hillock
Gray matter is _________ tissue and consists primarily of what two neuronal structures?
Unmyelinated; consists of Somas and Dendrites
White matter is ______ tissue; what neuronal structure does it primarily consist of?
Myelinated; consists of myelinated Axons
What organelles are present in the axonal hillock.
What is the axonal initial segment?
Portion of axon from axonal hillock to beginning of myelination
Pseudounipolar neurons are typically found where?
In the PNS, as part of sensory neurons. Ex. - sensory neurons with cell bodies in the dorsal root ganglia
Where are multipolar neurons typically found
In the CNS. Ex. - pyramidal cells of cortical regions, Purkinje fibers of the cerebellum, or motoneurons
Local circuit interneurons, such as those in the retina are usually what type of neuron?
What type of cells integrate information and send long axons to other brain areas? Other two names for these?
Principal cells; also called projection neurons or Golgi type I cells
What is unique about interneurons? What other two names are they known as?
They do not send their axons out of the local brain area. Also called Local Circuit neurons or Golgi Type II cells (either no axon or short, local axon)
What are the two types of synaptic transmission?
Electrical and chemical
What structures are needed for electrical synapses to function?
Most excitatory synapses in the brain are located on what structures?
What are the 4 types of synapse types?
The neuromuscular junction is also one; axospinous is a subtype of axodendritic
What is unique about chemical synapses in vertebrates compared to electrical synapses?
Chemical synapses transmit information unidirectionally
What is the presynaptic bouton or axonal varicosity?
Portion at end of axon where synaptic vesicles containing NT reside
What are two examples of excitatory NTs?
Acetylcholine and glutamate