Chapter 7 - Nervous System I (Neurons) Flashcards
Afferent (Sensory )Neurons Definition
Neurons carrying messages TO the CNS
*Located in Dorsal Root Ganglion
Efferent (Motor) Neurons Definition
Neurons carrying messages FROM the CNS
*Located in grey matter of spinal cord
(leaves CNS and goes to skeletal muscle)
Dendrites Definition
Projection from cell body that carry messages TO cell body
Axons Definition
Large projection that carry messages AWAY from cell body
Interneuron Definition
Located between sensory and motor neurons , within the CNS
- Integrate and interpret sensory signals
Myelin Definition
Myelin Sheath Definition
Myelinated Neurons Definition
Neurons with axons covering neuroglial cells that contain protein myelin
*Carry messages faster than non-myelinated neurons
Schwann Cells Definition
Form myelin sheaths
*Found in PNS
Oligodendrocytes Definition
Form myelin sheaths
*Found in CNS
Nodes of Ranvier Definition
Spaces on axon between glial cells
Ions Definition
Ion Channels Definition
Action Potential Definition
Sodium ions and Potassium ions crossing cell membrane through Ion channels
- Ion channel designed to only allow certain ions to pass through
Repolarization Definition
Caused by potassium ions leaving axon
*When potassium ions open up and allow K+ OUT of the axon, making the inside negative
(action potential travels down the axon)