Neuron Structure
Neurons Three classified types of neurons: Sensory Neurons Associative (inter neurons) Motor Neurons
Sensory Neurons Transfer message from receptors PNS to CNS. (3 types of receptors)
Sensory Neurons Exteroceptors: External, or on surface. (eyes, ears, skin ~ sense environment)
Sensory Neurons Propioceptors: Involved in balance and tension (muscles)
Sensory Neurons Interoceptors: Internal (digestion, hunger, excretion, heart, breathing)
Inter-neurons ONLY IN CNS!!!! Link sensory to motor
Motor neurons Message from CNS to effectors (muscles, glands)
Let us put it together! Roman Candle time.
NEURON STRUCTURE
COLOR CODE TIME PLEASE COLOR CODE THE NEURON ON PAGE 4. Color d, g, h, I, j, k, l and cell body
CELL BODY AKA Soma Contains nucleus, neuroplasm, nissl bodies.
Nissl Bodies Clusters of ribosomes (energy/protein makers)
Dendrites Receive signals, impulse carried towards cell body. Afferent process. (Carry toward)
Axon Carries outgoing signals (away from cell body = Efferent process Can branch to touch many fibers.
Myelin Insulated lipid that improves impulse speed. White in appearance
Myelin A. White matter: White appearance from myelin CNS
Myelin B. Gray matter: No myelin, outer part of brain (cortex) and some CNS
Neurilemma Thin membrane that surrounds axon in PNS. If nerve has neurilemma it CAN regenerate!
Node of Ranvier Gaps between glial cells where myelin is not complete. Saltatory conduction= jump from node to node.
Schwann cell Neuroglia cells which add myelin to axons of the PNS