Basic Neurology: Cellular Anatomy Flashcards
glial cells
These cells serve varied functions, including providing support, and removal of neurotransmitters from the synaptic cleft.
motor end plate
This refers to the end button/end bulb at the transition between the neuron and the muscle.
astoglia
These star-shaped glial cells are important in transporting nutrients from capillaries to nerve cells
synaptic vesicles
Neurotransmitters are stored in these vesicles, found at the terminal end buttons/end bulbs.
microglia
These glial cells are macrophages, helping to destroy harmful organisms by engulfing them. They also clean up dead or damaged brain tissue.
neurons
These are the basic building blocks of the nervous system. They are responsible for processing and transmitting messages throughout the entral and peripheral nervous systems.
axon
The portion of the neuron that transmits information away from the soma.
oligodendrocytes, oligodendroglia
Myelin sheaths within the central nervous system are produced by this type of glial cell.
soma
The cell body of a neuron.
synaptic cleft
The space between the end bulb/button and the next neuron’s soma or dendrite.
dendrite
This portion of the neuron often has branch like extensions, which receive information from other neurons or sensors.
neurotransmitters
These neurochemicals either transmit messages from neurons to other neurons, neurons to organs or muscles or act in a neuromodulatory role.
telodendria, terminal branches
These are the thin, end branches of axons.
multipolar
Most mammalian neurons have several dendrites and several axons. Thus their polarity is referred to as ________________.
myelin
The role of this substance is to speed transmission of neural conduction and reduce degradation of signal.
Schwann cells
Myelin sheaths within the peripheral nervous system are produced by this type of glial cell.
terminal buttons
These are the tips or end bulbs of axons or telodendria.
Nodes of Ranvier
These breaks between myelinated segments of myelinated axons are densely covered in sodium (Na) channels, allowing for regeneration of the action potential as it propagates down an axon.
neuromuscular junction, neuromuscular end plate
This refers to the synaptic cleft between the motor end plate and the muscle itself.
efferent (motor)
Motor pathways, which carry information from the CNS towards muscles or glands.
interneurons
These cells connect neurons to other neurons, either locally or over long distances.
afferent (sensory)
Sensory pathways, which carry information from sensory receptors toward the CNS.
acetylcholine
This is the neurotransmitter responsible for sending messages across the neuromuscular junction.
action potential
The process of stimulating a neuron adequately to produce a change in electrical potential allows for generation of a(n) ___________.
resting membrane potential (RMP)
This refers to the condition of a neuron’s cell membrane at rest. It is polarized, which means there is a net negative charge in the intracellular space and a net positive charge in the extracellular space.
Initiation of an action potential or spike leads to an influx of what ion?
sodium
depolarization
A change in polarity. The influx of sodium contributes to __________ of the membrane.
Once the action potential spike has peaked, what ion exits the cell in an effort to return to equilibrium or resting potential?
potassium
repolarization
This is the process of returning a depolarized cell back towards equilibrium or resting potential.
absolute refractory period
This refers to a period of time during which an action potential cannot be stimulated, no matter how strong the stimulus.
relative refractory period
This refers to a period of time during which an action potential can only be stimulated with a strong stimulus.
sodium-potassium ion pump
This structure actively transports ions across the neuron cell membrane in an effort to maintain a weighted equilibrium. It is responsible in part for returning a cell to its resting membrane potential following an action potential.
diffusion
This refers to the process of ions moving freely along the concentration gradient. When ion gates are open, this ion movement can contribute to depolarization and repolarization of the cell membrane.
saltatory condution
The process of transmitting an action potential from node to node. Gets its name from the prevalence of Na channels at the Nodes of Ranvier.
Propagation down an unmyelinated axon requires successive opening and closing of ______ channels throughout the length of the axon.
ion
temporal summation
This refers to the cumulative process of adding stimuli which occur in close time proximity to produce an action potential.
spatial summation
This refers to the cumulative process of adding stimuli which occur in close physical proximity to produce an action potential.
excitatory response
This refers to a message or stimuli, which excites another neuron.
inhibitory response
This refers to a message or stimuli, which inhibits another neuron.
pre-synaptic neuron
This refers to a message or stimuli, which inhibits another neuron.
post-synaptic neuron
This refers to the neuron about to receive the message.
the six main roles of glial cells
structure, transport nutrients, insulation, produce CSF, remove neurotransmitters from synaptic cleft, clean up injured/dead tissue
