Updated Quiz 2-Edited- 2018- QUIZ 2 D 301 Spring 2018 Final Exam.docx-Edited C R

Question

Updated Quiz 2-Edited- 2018- QUIZ 2 D 301 Spring 2018 Final Exam.docx-Edited C Regular Is 2.docxmL tne answers (tne tetter answer only ror your ce): Tne nnar exam score will De onyrtriequestionmumberan based on a total of 100 points. The exam is open-book, however, you are on your honor to not consult anyone else Essay Questions (10 points each, total 40 points). Answer each question as fully as possible. As specified for each question, you need only the required chapters/videos/websites for the answers- you are not required to use any additional information beyond the course material. You are free to add other resources, as long as you cite and reference them in APA-style, but this is completely optional. in the cked n and v .What are neurotransmitters, and how can they cause an action potential? For this answer, think about ld be forming a some of the concepts and terms from Week 2: receptors, ion channels, EPSPs/ISPSs, summation, threshold of excitation, and more havior level. P ers. The male p as monogamou emale Historically, a significant controversy in the field of biopsychology was the question of how our behavior is a result of nature (biology, genetics, inheritance) or a result of nurture (the environment we grow up in). Today, this is an obsolete position and it is believed by most that there is an interaction 50 points). C among genetics/biology and environment (or experience). The more accurate position is that behavior is due to an interaction between genetics/biology and experience le part not se le during a nig on to non-REN a the bn

Explanation / Answer

Neurotransmitters are endogenous chemicals which transmit electrochemical signals or nerve impulses from one neuron to another neuron, muscle cell or gland cell. They are stored in the synaptic vesicles in the synapses below the terminal buttons and are released into the synaptic cleft of the next cell. Once there, they bind with the specific receptors in the cell membrane of the postsynaptic cell. This causes the sodium ion(Na+) channels to open and the Potassium ion (K-) channels to close down. This results in a threshold potential which is the critical level to which a membrane potential must be depolarised to initiate a nerve impulse. This threshold potential is generally between -50 and 55mV. However, inhibitory neurotransmitters like GABA, increase the effluent of Potassium ions leading to hyperpolarization or increased negative charge inside the cell thereby causing inhibition of the threshold potential. Excitatory neurotransmitter such as Acetylcholine increase the resting membrane potential (-70 mV) by causing an influx of sodium ions inside the postsynaptic cell thereby producing a depolarisation or increased positive charge inside the cell. This depolarisation is required for the generation of the action potential.

Once in the cell, the neurotransmitter generates an action potential or a nerve impulse. A neuron that emits an action potential is said to ‘fire’. This action potential travels down the axon of the cell in one direction only and it is followed by a change in the polarity of the membrane. Action potential help in cell to cell communication andtake place through saltatory conduction that is they are generated at each myelinated part of the axon. The nerve impulse travels down the axon and reaches the terminal buttons at the synapse where it then makes connection with other cells. The process proceeds until all of the available sodium ion channels are open resulting in a larger proportion of sodium ions inside the cell than in the synaptic plasma. This reverses the polarity of the plasma membrane causing a closing down of the sodium ion channels so that no new sodium ions can enter the cell. They remaining Na ions are transported back out of the plasma membrane. POTASSIUM ion channels are then activated causing an effluent of K ions so that the electrochemical gradient is returned to the resting state after a neuron has fired.

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