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.