Neuron Modeling Kit in Brief

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In Brief: Key Teaching Points for the Neuron Modeling Kit©

Student Learning Objective: How Do Organisms Detect, Process and Use Information About the Environment? Using this kit teachers can guide their students to: • Construct and identify the parts of a multipolar neuron. • Distinguish between a multipolar neuron, bipolar neuron, unipolar neuron, and interneuron. • Describe the differences between the cells that compose the myelin sheath in the central and peripheral nervous systems. • Model simple and complex neural communication pathways.

Identifying the Parts of a Multipolar Neuron

Synaptic Knob Axon Hillock Dendrites Axon

Soma / Cell Body

Nucleus of Neuron Schwann Cell

Nucleus of Schwann Cell Myelin Sheath

Node of Ranvier

Key Teaching Points for Page 1 the Neuron Modeling Kit© 3dmoleculardesigns.com cbm.msoe.edu

Identifying Types of Neurons

Bipolar Unipolar Multipolar Interneuron (sometimes identified as pseudounipolar)

Type of Neuron Based on Location Functional Class Abundance Structure

Most abundant/ multipolar PNS/CNS motor/efferent major CNS neuron least common but typically found in the special sense bipolar most sensory retina of the eye, organs olfactory epithelium and vestibulocochlear nerve

commonly found unipolar in spinal cord and (psedounipolar) chiefly PNS most sensory cranial nerves

interneuron Conducts impulses (a special kind most abundant CNS from afferent to of multipolar (over 100 billion) motor neurons neuron) The Myelin Sheath

Neuron Oligodendrocyte

Schwann Cells Neurons

Peripheral Nervous System Central Nervous System

Key Teaching Points for Page 2 the Neuron Modeling Kit© 3dmoleculardesigns.com cbm.msoe.edu

Modeling Neural 2) Afferent Communication Pathways 1) Stimulus Monosynaptic Reflex – one synapse between the sensory neuron and the motor Unipolar neuron 3) Integration neuron center

Ipsilateral Reflex – the neural pathway is on one side of the spinal cord

Multipolar Example: Knee-Jerk Reflex 5) Effector neuron 4) Efferent

Polysynaptic Reflex – more than one synapse between the sensory neuron and the motor neuron 1) Stimulus 2) Afferent – the neural pathway is on Unipolar neuron Ipsilateral Reflex 3) Integration one side of the spinal cord center

Example: The Withdrawal Reflex Interneuron

4) Efferent 5) Effector Multipolar neuron

Polysynaptic Reflex – one synapse 2) Afferent between the sensory neuron and the motor neuron 1) Stimulus Unipolar neuron

Contralateral Reflex – the neural pathway 3) Integration involves both sides of the spinal cord center

4) Efferent Example: When stepping on a nail, the leg Multipolar with the foot that is stepping on the nail pulls neuron 5) Effector 5) Effector away, while the other leg bears the weight of Multipolar the body. neuron 4) Efferent

The Neuron Modeling Kit© can be borrowed from the MSOE Model Lending Library (cbm.MSOE.edu/LendingLibrary) or purchased from 3D Molecular Designs (3dmoleculardesigns.com). Find complete lessons and activities at http:// www.3dmoleculardesigns.com/Teacher-Resources/Neuron-Modeling-Kit.htm.