Nervous System Flashcards
Simplified Function of Nervous System
Sensory Input
Integration
Motor Output
Axon
each neuron has a single axon
Dendrites
Extensive branches from the cell body
Transmit chemical or electrical signals toward the cell
Nervous Tissue
Nuerons
Synapses
Sites at which neurons communicate
Two or more neurons
Presynaptic Neuron
Conducts the signal toward a synapse
Postsynaptic neuron
transmits chemical or electrical activity away from a synapse
Sensory neurons
make up the sensory division of the PNS, transmit impulses toward the CNS from sensory receptors in the PNS
Ganglia
Cell bodies found outside the CNS
Motor Neurons
make up the motor division of the PNS; they carry impulses away from the CNS to effector organs (muscles and glands).
cell bodies located in the CNS
Interneurons
located between the motor and sensory neurons
Synapse with sensory neurons
Confined entirely to the CNS
Reflex Arcs
Simple Chains of neurons
Responsible for reflexes
You can overcome the involuntary with a voluntary motion
Division of Nervous System
CNS-Brain, Spinal Cord
PNS-Nerves, Ganglia
CNS
Brain and Spinal Cord
A nucleus is a collection of nerve cell bodies within the CNS
A bundle of axons within the CNS connecting neighboring or distant nuclei of the cerebral cortex is a tract
Grey and White Matter
Nerve Cell bodies lie within and constitute the grey matter
The interconnecting fiber tract systems form the white matter
The gray matter appears roughly as an “H” in a cross section view.
