https://padlet.com/wentworthaw/x51z4tfizvehwxmc Abigail Wentworth en-us 2023-03-11 16:08:40 UTC 2023-03-13 03:14:57 UTC hello@padlet.com wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512966601 The central nervous system (CNS) is made up of neurons and glial cells (CrashCourse, 2015a; Stufflebeam, 2006).  Neurons receive information, decide how to respond, and then send out messages to other cells, enabling life to occur as it does (CrashCourse, 2015a; Stufflebeam, 2006).  For instance, neurons process information that allows for movement, seeing, hearing, feeling, and thinking (Stufflebeam, 2006).  As important as neurons are, there are far more glial cells than neurons in the CNS (CrashCourse, 2015a; Stufflebeam, 2006).  Glial cells are supportive cells that fill the space around neurons in the CNS, serving many different functions (CrashCourse, 2015a).  The most common glial cells in the CNS are astrocytes which ensure neurons are getting adequate blood flow (CrashCourse, 2015a).  In addition, microglial cells offer immune system support to the CNS (CrashCourse, 2015a).  Other glial cells protect neurons and increase the efficiency of receiving and outputting information (CrashCourse, 2015a).]]> 2023-03-12 04:49:16 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512966601 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512966928 There are four major areas of the neuron.  The cell body, also called the soma, is the source of power for the neuron; it also produces new neurotransmitters and disposes of proteins that are no longer useful (Stufflebeam, 2006).  Dendrites are the parts of the neuron that receive information from other cells in the body (Stufflebeam, 2006).  When the cell has determined its response, the axon, which connects neurons, outputs the information (Kolb et al., 2019; Stufflebeam, 2006).  At the end of each axon, there are axon terminals responsible for holding neurotransmitters (Stufflebeam, 2006).  ]]> 2023-03-12 04:50:45 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512966928 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967087 Action potentials in electronic devices and the body are similar; in both cases, positive and negative charges are separated but move to generate electric signals (CrashCourse, 2015b; Stufflebeam, 2006).  Electronics rely on wire circuits to move these electric charges while the neuron’s protein cell membrane maintains a negatively charged interior and positively charged exterior (CrashCourse, 2015b; Stufflebeam, 2006).  To generate an action potential, positively charged particles must cross through the cell membrane and into the neuron to meet a certain voltage threshold (CrashCourse, 2015b; Stufflebeam, 2006).  ]]> 2023-03-12 04:51:28 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967087 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967238 Ions are positively and negatively charged particles that are separated by the cell membrane (CrashCourse, 2015b).  When ions need to move into the cell or out of the cell to generate an action potential or return to equilibrium, gated channels open, allowing ions to pass through (CrashCourse, 2015b).  Further, different types of gated channels exist including those that are opened at a certain voltage and those that require a neurotransmitter (CrashCourse, 2015b).  In addition, sodium-potassium pumps move ions in and out of the neuron when necessary to maintain a negative charge inside the cell (CrashCourse, 2015b). ]]> 2023-03-12 04:51:51 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967238 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967449 A resting neuron has a charge of -70 millivolts which is achieved by having a more negatively charged cell interior than exterior (CrashCourse, 2015b; Stufflebeam, 2006).  The two main ions that contribute to this are sodium and potassium ions, both of which are positively charged (CrashCourse, 2015b; Stufflebeam, 2006).  The outside of a neuron has more positive sodium ions than the inside has positive potassium ions; the neuron also contains negative ions (CrashCourse, 2015b). ]]> 2023-03-12 04:52:35 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967449 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967551 When a neuron is stimulated, it begins to depolarize (Stufflebeam, 2006).  If it reaches -55 millivolts, the action potential is triggered and sodium gated channels open, allowing sodium ions to enter the cell (CrashCourse, 2015b; Stufflebeam, 2006).  As sodium ions are positively charged, the inside of the neuron becomes more positively charged than the outside (CrashCourse, 2015b; Stufflebeam, 2006).]]> 2023-03-12 04:53:00 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967551 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967683 To rebalance the electrical charges in the neuron, potassium gated channels open and potassium ions flood out of the cell (CrashCourse, 2015b; Stufflebeam, 2006).  This may result in hyperpolarization, or the cell becoming too negatively charged (CrashCourse, 2015b).  After the potassium gated channels close, the sodium-potassium pumps bring the electrical charges to a resting level by moving two potassium ions into the cell for every three sodium ions it pumps out of the cell (CrashCourse, 2015b).  While the cell is returning to a resting -70 millivolts, it is in a refractory period and cannot trigger another action potential (CrashCourse, 2015b; Stufflebeam, 2006).]]> 2023-03-12 04:53:32 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512967683 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512977449 Neurons are responsible for processing information that allows the body to move and the brain to operate (Stufflebeam, 2006).  As they fulfill this vital purpose, glial cells support neurons by connecting them, keeping them healthy and protected, and surrounding them (Stufflebeam, 2006).  In addition, each distinct part of the neuron has a unique function that keeps information flowing smoothly throughout the CNS (Stufflebeam, 2006).  Neurons use electrical signals to communicate; when an action potential is generated, positive ions rush into the cell membrane and make the overall charge of the neuron positive (Stufflebeam, 2006).  After the cell returns to a resting level, it is again ready to communicate with an action potential (Stufflebeam, 2006). ]]> 2023-03-12 05:34:07 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2512977449 wentworthaw https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2513700664 CrashCourse. (2015a, February 23). The nervous system, part 1: Crash course A&P #8 [Video]. YouTube. https://youtu.be/qPix_X-9t7E
CrashCourse. (2015b, March 2). The nervous system part 2 – Action! Potential! Crash course A&P #9 [Video]. YouTube. https://youtu.be/OZG8M_ldA1M
Kolb, B., Whishaw, I. Q., & Teskey, G. C. (2019). An Introduction to Brain and Behavior (6th ed.). Worth Publishers.
Stufflebeam, R. (2006). Neurons, synapses, action potential, and neurotransmission. The Mind Project. https://mind.ilstu.edu/curriculum/neurons_intro/neurons_intro.html]]> 2023-03-13 02:59:13 UTC https://padlet.com/wentworthaw/x51z4tfizvehwxmc/wish/2513700664