Cellular Neuroscience Flashcards
basic unit of organization of the nervous system
Neuron
part of the neuron that contains the nucleus and genetic information for protein synthesis.
Soma (cell body)
Materials move from the cell body along _____ and _____ by a process called _____.
microtubules
neurofilaments
axoplasmic transport
Highly branched outgrowths from the cell body
dendrites
In some cells (spinal motor neurons) the surface area of dendrites accounts for over ____ of the total neuronal surface area available for synaptic contact.
90%
Single process extending from the cell body that carries action potentials away from the cell body.
axon
____ axons conduct action potentials at a higher velocity than ____ axons.
Myelinated, unmyelinated
Myelin is formed by ____ cells and is not considered part of the neuron itself.
glial
Spaces between myelin-forming cells are called ____.
nodes of ranvier
____ are branches of axons which enable the neuron to activate more than one effector cell at a time
Axon collaterals
____ contain synaptic vesicles of chemical substances (____) for transmitting signals at the synapse.
Axon terminals
neurotransmitters
The nature of the action of a neuron on another cell type is determined by the ____ for the neurotransmitter.
post-synaptic receptor
Ion channels that allow negatively charged ions to flow into the cell will _____ the cell.
hyperpolarize or inhibit
Ion channels that allow positively charged ions to flow into the cell will _____ the cell.
depolarize or excite
Two types of summation of inputs that can also determine output of the post-synaptic cell are ____.
Spatial and Temporal summation
4 Types of Neurons are:
Unipolar
Pseudounipolar
Bipolar
Multipolar
____ have large dendritic trees and receive input from many sources (spinal motor neurons, purkinje cells in cerebellum)
Multipolar neurons
____ make up peripheral sensory afferents. Unique because they have 2 axons.
Psuedounipolar neurons
____ are found in special sensory systems (retina, auditory and vestibular systems)
Bipolar neurons
____ are found in invertebrates.
Unipolar neurons
____ neurons have receptors at their peripheral endings that respond to physical or chemical changes in their environment and cause electrical signals to be generated in the neurons.
Afferent
____ neurons transmit electrical signals from the CNS out to effector cells (muscle or gland)
Efferent
____ are found entirely within the CNS. These cells, which account for about 99% of all neurons, integrate inputs from many sources and are important components of reflex pathways and of pattern-generating circuits.
Interneurons
Functionally related groups of neuronal cell bodies are clustered together to form ____ and ____.
nuclei and ganglia
Terms to describe bundles of white matter include:
tract, fasciculus, lemniscus
Several tracts together form a funiculus
Neurons may also be described by the action of their neurotransmitter. Some of those groups are:
noradrenergic, cholinergic, dopaminergic, serotenergic, glutaminergic, GABAergic, glycinergic, peptidergic
Some glial cells called ____ may be excitable.
astrocytes
____ form the myelin sheath in the CNS
Oligodendrocytes
____ surround every CNS blood vessel and provide structural support for neurons.
Astrocytes
Astrocytes also secrete ____ which is vital for neurons.
growth factors
____ line the ventricles, cerebral aqueduct and central canal of the spinal cord and produce some CSF.
Ependymal cells
____ are the resident macrophages of the CNS. They are the first line of defense and carry out the immune response of the brain.
Microglia
____ form the myelin sheath in the PNS.
Schwann Cells (myelinating type)
____ surround cell bodies of neurons in sensory and autonomic ganglia.
Satellite cells
Provide trophic support to regenerating motor axons in the PNS following denervation.
Schwann Cells (non-myelinating type)
Resting cell membrane potential is approximately ____ mV.
-70 to -90