A & P Quick Cards 10, 11, 12, 16, 17, 18, 19
Saltutory Conduction
Jumping from node to node - nerve impulse. Is a consequence of myelination. Develops at Nodes of Ranvier, the bare axonal membrane. Increases speed with which nerve impulse travels along nerve fiber. 169
Oligodendrocytes
Makes nyelin in CNS.
Neurons
Nerve cells that transmit info as electrical signals.
Neuroglia (glia)
Nerve tissue that is called nerve glue; composed of astrocytes, microglia, oligodendrocytes, and ependymal cells. (CNS); Schwann Cells (PNS)
Axon terminals
Part of the axon where the neurotransmitters are stored.
Cell body
Part of the neuron that contains the nucleus; dendrites bring info to this structure, and the axon carries info away from this structure.
Axon
Part of the neuron that transmits info away from the cell body.
nodes of Ranvier
Short segments of the axonal membrane that are not covered by myelin sheath.
Repolarization
The depolarized neuron returns to the resting state. The second phase of the action potential that is cause by the outward movement of potassium (K+). 165-168
Dendrites
Treelike part of the neuron that receives info from another neuron and transmits that info toward the cell body.
Acetylcholine (ACh)
A common neurotransmitter.
What inactivates ACh
Acetylcholinesterase - enzyme. 170
Ganglia
Clusters of cell bodies located in the PNS. Cluster of cell bodies located outside of CNS.
Nuclei
Clusters of cell bodies located within CNS.
Astrocyte
Common type of glial cell that supports and protects the neurons; the cell helps form the blood-brain barrier.
Microglia
Glial cells that engage in phagocytosis of pathogens and damaged tissue.
Schwann cells
Glial cells that form the myelin sheath in the PNS (peripheral nervous system.
Depolarization
The inside of the neuron becomes positively charged. The first phase of the action potential caused by and inward movement of sodium (Na+). 165-168
Polarization (Resting state) or (resting membrane potential - RMP)
The inside of the unstimulated neuron is negative; this electrical charge is caused by the outward leak of potassium (K+). 165-168
Ependymal Cell
Type of glial cell that lines the inside cavities of the brain and helps form the cerebrospinal fluid.
Myelin Sheath
White, fatty material that surrounds the axon; it increases the rate at which the electrical signal travels along the axon. Makes white matter white. Allows for saltatory conduction of the nerve impulse.
Neurilemma
a layer of cell that covers the axon of peripheral neurons; concerned with ner regeneration.