Lesson 3 Assignment

Chemical C blocks the neurotransmitter receptors on the postsynaptic neuron

Anesthetics act to lessen pain by inhibiting nerve transmission. Which of the three substances listed might be the most effective anesthetic? (2 points)

Exocytosis of the neurotransmitter from the presynaptic neuron

Consider the action of a calcium channel blocker. Calcium channels blockers are used to treat high blood pressure. How do they work? During the transfer of information across a chemical synapse (involving a presynaptic neuron and a postsynaptic neuron), what step would be disrupted ("blocked") by a calcium channel blocker? (2 points)

Inhibit reuptake of the neurotransmitter

Consider the action of certain anti-depressive drugs. These drugs maintain an increased concentration of neurotransmitters such as serotonin within the synapse. How might these drugs cause this effect? (2 points)

More sodium ions flow into the neuron than potassium ions flow out of the neuron

During an excitatory postsynaptic potential (EPSP) (2 points)

WRONG - (d) See Section 12.5, page 532 in text.

During an inhibitory postsynaptic potential (IPSP) (2 points) a - the postsynaptic membrane depolarizes b - the postsynaptic membrane hyperpolarizes c - the postsynaptic neuron releases less neurotransmitter d - calcium ion entry into the presynaptic terminal is prevented

Excessive levels of nicotine might cause respiratory paralysis because it will keep channels open that will cause muscle to remain depolarized and unable to contract. This will block the transmission of signals, leading to muscle weakness and paralysis. https://science.howstuffworks.com/nicotine6.htm

Extra Credit: One of the hallmarks of addiction is the withdrawal symptoms that occur when a person stops ingesting the addictive substance. Nicotine withdrawal symptoms include lethargy, hunger, and irritability. To avoid these withdrawal symptoms, people who are trying to stop smoking may use a nicotine patch. These adhesive patches deliver a small, continuous dose of nicotine that is usually enough to keep the withdrawal symptoms in check. When you look more closely at the nicotine package insert however, you will notice a warning to keep the patches away from children. An overdose of nicotine (highly unlikely when the patch is used as directed) could result in complete paralysis of the respiratory muscles (the diaphragm and skeletal muscles of the chest wall). (5 extra credit points) Here's your question... Why might excessive levels of nicotine cause respiratory paralysis? Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

Increase Na+ permeability.

How could you increase the magnitude of excitatory postsynaptic potentials (EPSPs) generated at a synapse? (4 points)

sympathetic

If a neuron releases norepinephrine, which division of the peripheral nervous system is it a part of? (2 points)

hyperpolarize the membrane

Neurotransmitters categorized as inhibitory are expected to ________(2 points).

The sympathetic nervous system controls nervous system activity that prepares the body to deal with a threat, real or imaginary. It prepares the body by producing physiological changes that allow us to oppose the threat (fight) or flee the threat (flight). The changes produced include heart and respiratory rate becoming elevated, pupils dilating, increased flow of blood to cardiac and skeletal muscle, and excess oxygen sent to the brain to increase alertness. Sympathetic activity explains our increased "jumpiness" when we're home alone at night, watching a horror movie on TV because the movie is scary and even though there's no real threat it can still trigger the sympathetic nervous system response. Once the response is triggered we undergo the physiological changes and become ready for action and more alert which we experience as increased "jumpiness." https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response (Links to an external site.)

Short answer question: Explain the use of the terms fight and flight in describing sympathetic motor responses. How does sympathetic activity explain your increased "jumpiness" when you are home alone at night, watching a horror movie on TV? (6 points) Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

Ginger's heart continued to beat rapidly for another 30 minutes because although the initial threat had passed she was still anxious because of the noise so her body was still in high alert mode. https://psu.instructure.com/courses/2179322/pages/divisions-of-the-nervous-system?module_item_id=34205116

Short answer question: Ginger was enjoying a quiet evening watching television when she hear a loud bang that she thought might be a gunshot. Immediately her heart began to beat rapidly. She later learned that the noise was just the sound of a firecracker. While she was glad that the sound was not a gunshot, her heart kept beating heavily for another 30 minutes. Why did her heart to continue to beat rapidly? (6 points) Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

Javier's sympathetic nervous system was at work when he heard someone following him and felt like he was in danger, it caused him to become excited and more alert but once he was safe his parasympathetic system kicked in. This triggers his body to reverse the sympathetic system's response and promote "rest and digest" which explains why Javier felt the need to urinate once safe. https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response (Links to an external site.)

Short answer question: Javier was walking through a dark alley heading for home after work. He heard someone following him and decided to run to a nearby crowded street to escape any danger. Once he felt he was safe, he noticed he had an intense feeling that he needed to urinate. Using your understanding of the nervous system, explain this response. (6 points) Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

After eating a big meal you might feel tired because the parasympathetic division of the autonomic nervous system is dominating. This division controls the "rest and digest" response which increases digestion, slows down respiration, and slows down heart rate; it does all of this so that the body can restore itself. https://psu.instructure.com/courses/2179322/pages/divisions-of-the-nervous-system?module_item_id=34205116

Short answer question: We've all had the experience of feeling quite tired after eating a big meal. Based on your understanding of the autonomic nervous system, explain why you might feel tired. (4 points) Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

The receptor is the important element determining the effect a neurotransmitter has on a target cell because the receptor has power to trigger ion channels and the type of receptor determines which channel is opened. https://www.khanacademy.org/science/biology/human-biology/neuron-nervous-system/v/neuronal-synapses-chemical (Links to an external site.)

Short answer question: Why is the receptor the important element determining the effect a neurotransmitter has on a target cell? (6 points) Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

The presynaptic neuron receives a signal or multiple signals on its dendrites. The signal is summed up and the combined effects move through the soma until they reach the hillock. Once at the hillock if the signal is strong enough it will then trigger an action potential. The action potential will cause the signal to travel the remainder of the axon triggering sodium channels along the way. Near the end of the axon there are calcium channels that will then be triggered instead of the sodium channels. Once the calcium channel is triggered calcium ions flood into the terminal end of the axon. Inside the terminal end of the axon there are vesicles that are docked by S.N.A.R.E proteins to the presynaptic membrane that house neurotransmitters. The calcium ions once in inside the terminal end bind to the S.N.A.R.E proteins and change their confirmation enough to bring the vesicles closer to the membrane. The proteins then pull apart the two membranes so that the vesicle membrane and the presynaptic neuron membrane merge. This merge triggers the exocytosis of neurotransmitters from the vesicle into the synaptic cleft. Once in the synaptic cleft the neurotransmitters bind to the surface of the postsynaptic neuron receptors, this binding triggers ion channels. If a sodium channel is triggered the postsynaptic neuron will be excited, if a potassium channel is triggered, the postsynaptic neuron will be inhibited. https://www.khanacademy.org/science/biology/human-biology/neuron-nervous-system/v/neuronal-synapses-chemical

Short answer question: Discuss the order of events happening at a chemical synapse. (10 points) Begin with the stimulation of the presynaptic neuron and the generation of the action potential. Assume threshold is reached. What are the roles of calcium ions at the axonal terminal? Explain the function of ALL of the following: the neurotransmitter, the postsynaptic neuron receptors, the synaptic cleft, the synaptic vesicles, removal of the neurotransmitter, excitation or inhibition of the postsynaptic neuron, the ion (sodium, potassium, calcium, etc.) channels affected? Be sure to use your own words. Do not use abbreviations. Include a citation for the reference (text or other sources) you used in formulating your response. If you do not include a citation, you will lose 2 points for this question.

True

TRUE OR FALSE: The autonomic nervous system may cause activation or inhibition, depending on the division that is active and the target that is affected. (2 points)

FALSE Both divisions innervate the same organs. See page 656 in text.

TRUE OR FALSE: The parasympathetic division innervates more organs than the sympathetic division. (2 points)

mechanoreceptors

Tactile sensation is a combination of touch, pressure, stretch, and vibration. Which of the following is most likely the receptor type that senses tactile stimulation? (2 points)

degradation on the postsynaptic membrane

The activity of acetylcholine in a synapse is terminated by its ________ (2 points).

both thoracic and lumbar

The sympathetic nervous system originates in the _______ region(s) of the spinal cord. (2 points)

propioceptors

We can touch our finger to our nose while our eyes are closed in part because we can sense the position and movement of our joints as well as the length of stretch in our muscles. These sensations create awareness of our body's positioning. Which of the following receptors are most likely responsible for this ability? (2 points)

No action potential results.

What happens if twice as many inhibitory postsynaptic potentials (IPSPs) as excitatory postsynaptic potentials (EPSPs) arrive in close proximity at a postsynaptic neuron? (4 points)

WRONG - (a&d) See Section 12.5, page 534 in text.

Which of the following are characteristics of a chemical synapse? Choose all that apply. (2 points) a - Release of neurotransmitter by exocytosis from the presynaptic neuron b - Receptors for the neurotransmitter are present on the postsynaptic neuron c - The presynaptic neuron and the postsynaptic neuron are physically connected together d - The synaptic cleft is a space separating the presynaptic and postsynaptic neurons

Occurs when pain is felt at a site other than the area where the pain originates; pain in the left arm may occur with a heart attack

Which of the following best describes referred pain (2 points):

WRONG - (a) See Instructor review of Lesson 3 part 2 beginning at 16:30.

Which physiological responses results from sympathetic action? (2 points) a - increase in heart rate b - constriction of arterioles c - increase in digestion d - stimulation of glycogenolysis e - Choices A, B, and D are correct.

WRONG - (a) See Section 12.5, page 534 in text.

Which statement about synapses is correct? (2 points) a - Cells with shared cytoplasm are coupled chemically b - Neurotransmitter is released when cells are electrically connected c - Neurotransmitters' receptors are present in the axons of neurons d - The synaptic cleft separates two neurons and prevents direct transmission of impulses between them