Nerve And Neuron Analysis

Nerve and neuron sound similar to most people, but they are two different components of the body (Martini, 375). Nerves are found only in the peripheral nervous system, while neurons are found in the brain, spinal cord, and peripheral nerve (Martini, 375). Neurons are nerves cells that are specialized for intercellular communication (Martini, 375). A neuron is composed of a cell body, dendrites and axon (Marieb, 376). A nerve is a bundle of axons or dendrites that is wrapped in connective tissues (Martini, 376). The nerve transport impulse between the central nervous system and other parts of the body (Martini, 376). A Myelin sheath can be found in both nerves and neurons (Martini, 383). Myelin is an electrical insulation on the axon that increases the speed at which action potential travels
along the axon (Martini, 381). Action potential is a change in the transmembrane potential of excitable cells initiated by a change in the membrane permeability to sodium ions (Martini, 376). An action potential in a neuron plasma membrane is a nerve impulse (Martini, 377). Action Potentials are circulated in the trans membrane potential that if started it affects the entire excitable membrane ( Martini,394).
The sodium potassium pump maintains the difference in electrical charge found by the diffusion of ions (Marieb, 125).
The resting membrane potential is the difference in electrical charge across the plasma membrane (Marieb, 125). The resting membrane potential can be measured with a voltmeter by putting a recording electrode inside the cell membrane (Marieb, 125). The process of moving sodium and potassium ions across the cell membrane is called active transport (Martini, 384). Active transport moves three sodium ions out of the cell while moving two potassium ions into the cell (Marieb, 125). A threshold stimulus occurs when a neuron is activated by a stimulus of adequate intensity causing the membrane to reach its trigger zone and becoming more permeable to sodium (Marieb, 126). When this occur the sodium ion channels in the cell membrane opens. Once the sodium enters the cell membrane the number of positive ions inside the cell is increased causing the cell to become more positive and less negative (Marieb, 127). When the interior of a cell membrane is more positive and the exterior surface of the surface is more negative this occurrence is depolarization (Marieb,
127).
Curare is an alpha-toxin that binds to acetylcholine binding site on postsynaptic cell membrane, it presynaptic cell membrane, it prevents the acetylcholine from acting (Marieb, 131). The synaptic transmission is blocked by preventing the flow of neural impulse from neuron to neuron (Marieb, 131). South American Indian were know to use this well know plant extract to paralyze their prey, because it affects the skeletal muscles (Marieb, 131). Lidocaine is a sodium- channel antagonist that prevents sodium channels from opening (Marieb, 131).
Materials and Methods
I used the PhysioEx CD for Exercise10 Activities 6 and 7
Results
Table 1. Inhibiting a Nerve Impulse Voltage Action Potential Curare 4.0 Yes
Lidocaine 4.0 No

Discussion
Lidocaine had no action potential. Lidocaine didn’t reach a threshold, meaning there was no change in its polarity. The interior surface of the membrane didn’t become less negative than the inside of the membrane. When a cell has equilibrium in their charges there is no action potential, because they are both the same and cannot attract to reach a threshold.
Curare was activated by a stimulus of adequate intensity causing it to reach its threshold initiating action potential.