Neurons and Glia Flashcards
Secretes chemicals into bloodstream
Neuroendocrine
Changes shape when inflammation is found. Becomes an ameboid
Microglia
Tripartite synapse
Formed by astrocytes to keep neurotransmitters in
Involved in myelination around axons
Oligodendrocytes and Schwann cells
Reduces work done by sodium-potassium pumps
myelin
Single elongated process with cell body off to side (sensory receptors in joints to know if movement happened)
Pseudounipolar
Brain and spinal cord to muscles and organs
Efferent. Motor
Structural support to axon
Neurofilaments
Connects one neuron to another in brain or spinal cord. Vast majority of neurons.
Interneuron
Cytoplasm, organelles, and the nucleus are found here
Cell body (Soma)
Two processes separated by cell body. Often sensory
Bipolar
Antigen presentation allows them to recognize and destroy previously seen before bacteria
Microglia
Blood brain barrier
way of keeping things in the blood from the brain and brain from blood
10-15% of all cells in the brain
Microglia
Contains protein molecules, receptors, channels/pumps, transporters
Neural membrane
Micro and macro versions of this cell
glia
Contains mitochondria and synaptic vesicles containing neurotransmitters
Axon terminal
Communicate with neurons in distant areas of the nervous system
projection neurons (very long)
Most of the brain mass is here but there are less neurons than glia
cerebral cortex
No need for ion channels under these
myelin sheath
Starts at the axon hillock where axon join cell body
axon
Sensitive to type and amount of synaptic activity
Dendritic spine
Gaps between myelin sheaths are called
nodes of ranvier
Form structural matrix for neurons. Contribute to blood brain barrier. Regulate chemicals around neurons. Form scar tissue that inhibits regrowth and connectivity
Astrocytes
Protoplasmic astrocytes
Thick projections with many branches. Found in gray matter
Provides metabolic (energy -ATP) and synthetic (protein) support
Cell body (soma)
Conducts action potentials
axon
One per many dendrites
axon
Secrete cerebrospinal fluid (CSF)
Ependymal cells
Selectively permeable. Allows polarization
Neural membrane
Fibrous astrocytes
Long and slender with less branches. Found in white matter
Provides insulation and allows for smaller diameter axons
myelin
Small amount of brain mass and very small percentage of neurons here
basal gang, dienceph, brainstem
Cell body to axon terminal (forward acting)
Anterograde
In the PNS. One cell myelinated a single axon segment
Schwann Cells
When an axon branches off but is still just one axon
axon collaterals
From brain to spinal cord
Afferent. Sensory
Non-neural (no action potentials)
glia
Primary supporting cells of the CNS
glia
Diameter of axon/speed relationship
Larger diameter = faster signals
Smaller diameter = slower signals
Damage of these is associated with multiple sclerosis
Oligodendrocytes and Schwann cells
Which neurons are always myelinated
motor
Reorganization of neuronal branches
Microfilaments
Involved in blood brain barrier
Ependymal cells
Primary functioning cells of the CNS
neurons
Structural scaffold during early neurodevelopment
Radial glia
Many dendrites and a single axon. Most common
Multipolar
Receives integrates signals from many sources of input (integration zone)
Cell body (soma)
Communicate with neurons in immediate vicinity
local circuit (short)
In the CNS. One cell myelinated about 15 axons
Oligodendrocytes
Receive chemical messages from other cells, conduct post-synaptic potentials toward cell body
Dendrites
Most common glia coming in fibrous and protoplasmic types
Astrocytes
Located in the choroid plexus
Ependymal cells
Give more surface area to increase amount of potential inputs
Dendritic spine
Axon terminal to cell body (backward acting)
Retrograde
Shows plasticity (change over time)
Dendritic spine
White blood cells do the job of these everywhere but the CNS
Microglia
Receives thousands of inputs
Dendrites
Why is it easier to repair damage in the PNS as opposed to the CNS?
The oligodendrocytes in the CNS myelinate multiple axons whereas the Schwann cells in the PNS myelinate a single axon segment
Made of phospholipid bilayer
Neural membrane
Form tripartite synapse and participate in isolation and uptake
Astrocytes
Most of the brain neurons are here but it is a small part of the brain mass
Cerebellum
Six types of glial cells
Astrocytes, oligodendrocytes, Schwann cells, ependymal cells, radial glia, microglia
Dendritic spine degree of maturity
Mature - Immature
Mushroom spine, thin spine, stubby spine, filopodia
Responsible for transport of neurotransmitters and other cellular products to and from the cell body
Microtubules
Group of dendrites on one cell
Dendritic arborization
Help new neurons radiate outward and reach their final destination
Radial glia
These are found in the membrane lining ventricles and central canal of spinal cord
Ependymal cells
Information processing and communication
neurons
Acts to gate information flow to and from other neurons
Cell body (soma)
Defines intracellular/extracellular boundaries
Neural membrane
Small protrusion that receives input from a single axon
Dendritic spine
Which neurons are sometimes myelinated
sensory
Activated by inflammation
Microglia
Proliferative. Neural and glial progenitors
Radial glia
Immune defense in CNS
Microglia
General roles of glial cells
Glue. Physical and functional support functions to neurons. Help keep neurons healthy.
Phagocytose molecules associated with cellular damage
Microglia
Two types of cells in nervous system
neurons and glia
