1.3 Neuroglial Cells Flashcards
What does a nerve consist of?
hundreds of thousands of axons wrapped together in connective tissue
What are ganglia?
masses of cell bodies of neurons from the PNS
What are Neuroglial cells?
support cells for neurons
What are Schwann cells?
insulate the nerve fiber and increase the speed of nerve impulses
Where are Schwann cells found?
coat the axons of PNS axons
What are Schwann cells composed of?
myelin sheath
What is the myelin sheath?
white fatty layer
How are Schwann cells associated with grey matter?
loosely associated; do not wrap around the axon
What are the Nodes of Ranvier?
gaps in between the Schwann cells insulating sections
What do the Nodes of Ranvier cause?
saltatory conduction; the electrical impulses have to jump between the nodes
What is the benefit of saltatory conduction?
greatly increases the nerve impulse transmission along the axon
What are satellite cells?
cells that surround the cell bodies of peripheral nerves that help regulate the cell body environment
What can regrow in the PNS?
axons under certain conditios
How do peripheral nerves axons regrow?
Schwann cells will grow ahead of the axon leaving a path for the axon to grow
What is axonal regeneration?
the process of peripheral nerves regenerating the axon length
What are the Neuroglial cells of the CNS?
ependymal cells
oligodendrocytes
astrocytes
microglial cells
What are ependymal cells?
circulate cerebrospinal fluid and allow fluid exchange between brain, spinal cord, and CSF
What is cerebrospinal fluid?
clear fluid that only circulates in the brain and spinal cord
What are oligodendrocytes?
act as insulation for the CNS
What are astrocytes?
control the chemical environment of neurons by wrapping around blood capillaries
