Anatomy

Structure of a neuron

Directions: Use the text to find the information for the following questions. Be sure to use in-text referencing and include the proper reference documentation at the end of the assignment.

1. In the space below, make a diagram of a multipolar neuron. Be sure to label the following: dendrite, axon, cell body, node of Ranvier, myelin sheath, Schwann cell and direction of nerve impulse.

2. Compare and contrast motor, association and sensory neurons on the basis of function and direction of impulse travel.

They transport impulses. Sensory neurons are responsible for converting external stimuli from the environment of an organism which produces corresponding internal stimuli. Association neurons form connections between other neurons. They are not motor or sensory. A motor neuron is a nerve cell that forms part of a pathway which impulses pass from the brain or spinal cord to a muscle or gland.

3. Describe the all-or-none response of nerve impulses and compare it to the all-or-non response of motor unit contract.

The all-or-none response of a nerve impulse is that the strength that the muscle fiber responds with to the stimulus is not dependent on the stimulus itself. If the stimulus is strong enough it and the muscle fibers will give complete responses, if not then they both will give no response. The all-or-none response of motor unit contract is the contraction of all the fibres in one motor unit. When motor units all the fibres in that unit contract at full force. They strength depends on the number of motor units recruited.

4. Describe saltatory conduction. Contrast both the structural and functional difference this creates compared to other neurons.

Saltatory conduction is the propagation of action potential along myelinated axons from one node of Ranvier to the next node.

Work Cited

"Membrane Potential." Wikipedia. Wikimedia Foundation, 15 Mar. 2014. Web. 20 Mar. 2014.

"Multipolar Neuron - Google Search."...