1: Basic Organization of the Nervous System Flashcards
Neurons
the major functional unit of the nervous system
Neuroganglia
cells that play an important tole in supporting the neurons
Nerve
a bundle of axons held together by connective tissue
Cell body
integrated information, synthesizes and processes proteins for the neuron
What are 2 other names for a cell body?
- soma
- perikaryon
Dendrites
numerous short processes that receive information from other cells, contain receptors for neurotransmitters
Axon
moves materials from cell body to synaptic terminals, carry action potentials, may be insulated with myelin
Myelin
covering on the axon, not always present
Axon hillock
cone-shaped segment of cell body, part of “trigger zone” where action potentials are generated
Presynaptic termianls
collection of fine branches at distal end of axon
Synapse
specialized junction that allows neurons to communicate with other cells
Myelin functions
- increase speed of conduction
- protection
- insulation
- repair neurons
Axons with larger diameter have ____ conduction velocity
faster
White matter
regions are axons with myelin sheats
White matter in CNS
nerve tracts in spinal cord and brain