Week 2—2 Peer Response 800w. due9-16-23

Instructions:

Please read and respond to the two peers' initial postings for week 2 below. Consider the following questions in your responses.

Compare and contrast your initial posting with those of your peers.  

1. How are they similar or how are they different?

2. What information can you add that would help support the responses of your peers?

3. Ask your peers a question for clarification about their post.

4. What most interests you about their responses? 

5. Summaries at least 1 evidence based article that supports there point.

Please be sure to validate your opinions and ideas with citations and references in APA format.

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Response 1 400 words

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Week 2 Discussion: Neurotransmitters

Describe the chemical and electrical processes used in neurotransmission.

        The central and peripheral nervous system both have a very complex and precise structure. The brain has trillions of specialized nerve cells called neurons. Neurons are connected to each other via synapses. Each neuron is connected to thousands of other neurons. Synapses serve as specialized centers that direct communication between neurons via a mechanism known as neurotransmission (Masoli et al., 2022). In other words, neurotransmission means how an impulse moves through one neuron to another neuron. Pulses can move through neurons electrically or chemically.

        Electrical process involves cell membranes. Each neuron has a cell membrane that separates intracellular space from extracellular space and has electrical charge (ions). When a signal arrives to the cell membrane, the ion channels both voltage-sensitive sodium channels (VSSCs) and voltage-sensitive calcium channels (VSCCs ) open and NA+  ions can transfer through these channels and create electrical signals (action potential). This electrical signal will move through axons to reach to the axon terminal (presynaptic nerve terminal) and opens calcium channels.

        According to Huang et al. (2022), in the nervous system, the functioning of brain circuits depends on the accurate integration of synaptic vesicles filled with neurotransmitters at a region known as the presynaptic active zone. When an action potential reaches these vesicles and calcium ions are transferred, the neurotransmitters are released from these vesicles. In other words, electrical impulses within the neuron are then transformed into chemical messengers, a process known as Excitation–Secretion Coupling. When these messengers (neurotransmitters) are released, they activate the receptors on a postsynaptic neuron. Communication within a neuron is electrical, while communication between neurons is chemical (Stahl, 2021). A single synapse can have many communication lines, each using its own neurotransmitter, and each neurotransmitter can be understood by a different set of receptors. This complex setup allows for rich and diverse communication between nerve cells (Agnati et al., 2023).

Why are depolarizations referred to as excitatory postsynaptic potentials and hyperpolarization as inhibitory postsynaptic potentials?

        The neurotransmitter can affect the postsynaptic neuron's cell membrane in two different ways. If the neurotransmitter binds to the receptors on the postsynaptic neuron and reduces the negative charge of the cell membrane, causing slight depolarization, the postsynaptic neuron will reach the threshold to initiate an action potential and transmit signals further along the neural pathway. This process is called Excitatory Postsynaptic Potentials (EPSP). In other words, when the neurotransmitter depolarizes the postsynaptic cell membrane, it is termed excitatory because it initiates an action potential (Stahl, 2021).

        On the other hand, if the neurotransmitter binds to the postsynaptic cell membrane and creates a more negative charge, hyperpolarization occurs. In this case, the postsynaptic neuron receives an inhibitory signal, which means the neuron moves further away from the threshold for initiating an action potential. This pathway is referred to as Inhibitory Postsynaptic Potentials (IPSP). The balance between EPSP and IPSP regulates the activity of neurons (Stahl, 2021).

What are the differences between absolute and relative refractory periods?

        When a neuron has been depolarized and an action potential has been created, this neuron is not anymore able to start another action potential for a limited amount of time. The duration, lasting approximately 1-2 milliseconds, beginning with the initiation of the action potential and extending just beyond the spike potential. This period is referred to as the Absolute Refractory Period (ARP). It's important to note that, even in response to stronger or supra threshold stimuli, no additional action potentials can be generated during the ARP. During this period, sodium channels are closed and sodium ions are not able to flow and create another action plan (Kartik et al., 2023). This is because the system prefers to create one-directional manner and prevent backward transmission of signals along the neuron's axon.

        Relative refractory period usually follows absolute refractory period. Some neurons acquire their abilities to create another action potential little by little, however, the signal should be stronger to depolarize the neurons. Following the inactivation of the sodium (Na) channels, the opening of potassium (K) channels leads to the efflux of K ions. Subsequent recovery of the Na channels from their inactivated state permits the generation of a second action potential. However, due to the sustained efflux of K ions, there is a natural resistance to further depolarization. As a result, a stimulus stronger than the norm is required to start a second action potential (Kartik et al., 2023). This period, lasting approximately 3-4 milliseconds after the absolute refractory period, during which a second action potential can be fired with stronger stimuli due to the recovery of Na channels. The reason of this period is that some ion channels have been recovered and now are able to open their channels and let the sodium ions to flow and create action plan. The relative refractory period is usually longer that absolute refractory period. These refractory periods help to ensure proper timing in neural circuits (Stahl, 2021). 

References

Agnati, L. F., Guidolin, D., Cervetto, C., Guido, M., & Marcoli, M. (2023). Brain structure and function: Insights from chemical neuroanatomy.
 Life, 13(4), 940. 
https://doi.org/10.3390/life13040940Links to an external site.

Huang, S., Piao, C., Beuschel, C. B., & Zhao, Z. (2022). A brain-wide form of presynaptic active zone plasticity orchestrates resilience to brain aging in Drosophila.
 PLoS Biology, 20(12) 
https://doi.org/10.1371/journal.pbio.3001730Links to an external site.

Kartik, S., Hrudini, D., Aparna, J., Navya, T., & Chelliah, S. (2023). “Knowing it before blocking It,” the ABCD of the peripheral nerves: Part A (Nerve anatomy and physiology).
 Cureus, 15(7) https://doi.org/10.7759/cureus.41771

Masoli, S., Rizza, M. F., Tognolina, M., Prestori, F., & D’Angelo, E. (2022). Computational models of neurotransmission at cerebellar synapses unveil the impact on network computation.
 Frontiers in Computational Neuroscience,

 
https://doi.org/10.3389/fncom.2022.1006989Links to an external site.

Stahl, S. M. (2021). 
Stahl’s essential psychopharmacology: Neuroscientific basis and practical application (5th ed.). 

Response 2. 400 words

Describe the chemical and electrical processes used in neurotransmission.

Neurons which are nerve cells can communicate with each other through electrical and chemical signals. Communication occurs at the synapses; this is the site where chemical transmission occurs (Lovinger, 2008). Presynaptic neurons release neurotransmitters which are then received by the postsynaptic neuron also referred to as the neurotransmitter receptor protein (Lovinger, 2008). Neurotransmitter molecules bind to the receptor protein thus changing its function. Electrical signals also called action potential on the other hand are a result of charged particles that create rapid conduction from one end of the cell through the axon and to the next, its speed is dependent on the myelin sheath (Lall, 2023)

Why are depolarizations referred to as excitatory postsynaptic potentials and hyperpolarization as inhibitory postsynaptic potentials?

Depolarizations are referred to as excitatory postsynaptic potentials and hyperpolarization as inhibitory postsynaptic potentials due to the synaptic response that is facilitated by the Ligand-gated ion channels. In other words, the response of the postsynaptic neurons determines if it is excitatory (fires an action potential) or inhibitory (doesn’t fire an action potential) (Lovinger, 2008). Depolarization refers to the opening of sodium ion channels allowing an influx of sodium to enter the cell membrane increasing the likelihood of an action potential. This is followed by resting potential and rapid repolarization (Grider, 2023).

What are the differences between absolute and relative refractory periods?

An absolute refractory period is a period that follows an action potential in which a second action potential cannot occur due to the inactivation of the voltage-gated sodium channel (Grider, 2023). Whereas the relative refractory period is the duration of time in which a second action potential can occur. During this time sodium channels move from an inactive state to a closed state, however, in order for an action potential to happen a larger amount of stimulation is needed (Grider, 2023).

 

References

Grider, M. H. (2023, May 8). 
Physiology, action potential. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK538143/#:~:text=In%20neurons%2C%20the%20rapid%20rise,opening%20of%20potassium%20ion%20channels.

Lall, S. (2023, May 24). 
How do neurons communicate (so quickly)? – MIT McGovern Institute. MIT McGovern Institute. https://mcgovern.mit.edu/2019/02/28/ask-the-brain-how-do-neurons-communicate/

Lovinger, D. M. (2008). 
Communication Networks in the Brain: Neurons, Receptors, Neurotransmitters, and Alcohol. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3860493/#:~:text=Nerve%20cells%20(i.e.%2C%20neurons),the%20cell%20to%20the%20other.

 ReplyReply to Comment

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Read the following case study and answer the reflective questions.  Please provide evidence-based rationales for your answers.  APA, 7th ed. must be followed. 

 

Identifying and justifying appropriate Study Designs · 

Step 1:  A not-for-profit organization called Epidemiologists Without Borders has reached out to student researchers studying epidemiology at Florida National University. The organization has asked for support in the design of three research projects they plan to carry-out in several of the communities where they currently work. Read these three case studies summarized below.

NOTE: You may substitute one of the case-studies outlined below for a case study that is relevant to your own community. If you choose to do so, generate a case-study regarding a public health problem that is relevant and requires epidemiological research. Include the case study when you submit your assignment.

Case study 1:

Vaginal cancer is a rare disease that can often be cured when detected in its early stages. Vaginal cancer occurs more often in women over the age of 50 but can occur at any age. There are usually no symptoms for vaginal cancer. Epidemiologists Without Borders has been awarded a large grant to study the relationship between vaginal cancer and prior exposures to any risk factor among women in a South African city.  

Case study 2:

Epidemiologists Without Borders has learned that a large group of employees who have worked in a specific building (building A) of a very large corporation for more than 25 years appear to have high cancer incidence rates. The corporation has a total of 3 office buildings (buildings A, B, and C). Epidemiologists Without Borders would like to conduct research to determine if the rates of cancer incidence among those workers from building A are in fact higher than expected.

Case study 3:

Epidemiologists Without Borders supports the rights to life, health, and dignity for people who use illicit drugs. The organization is concerned about the high rates of HIV infection it has observed in one particular community and suspects that there are many risk factors possibly contributing to this high HIV risk. Currently, the data in this community with respect to the exact HIV incidence rate among injection drug users is of poor quality but estimates indicate that the prevalence is as high as 10-20%. Access to HIV testing is also low in this population. Additional challenges include limited resources, and the difficulty in recruiting people for testing due to their high mobility and hidden social networks. 

Epidemiologists without Borders would like to identify potential risk factors for contracting HIV among injection drug users in this community so that it can develop appropriate interventions.

Step 2: Select the most appropriate study design for each of the three case-studies proposed by Epidemiologists Without Borders (or for the one relevant in your community) based on what you have learned in this Week’s Lectures, Readings, PPT’s and modules. 

Step 3: Write a letter responding to Epidemiologists Without Borders outlining the study designs that you recommend. Justify why the study designs you selected are appropriate for each of the three case-studies. Your response must also outline at least one benefit and one limitation for each of the study designs you have recommended for each case-study. Your letter to Epidemiologist Without Borders should be clear and concise and contain no more than 450-550 words.  

Please be sure to adhere to the following when posting your weekly discussions:

1. Students are to write their name and the appropriate discussion number/discussion title in the title bar for each discussion. For example, Discussion 1: Micheal Cabrera or Discussion 3: Sheila Smith. This is important in identifying that students are submitting original posts as well as response posts as required.

2. Students are to submit their discussions directly onto Blackboard Discussion Board Attachments submitted as discussion board posts will not be graded.

3.  As a reminder, all discussion posts must be minimum 350-550 words, references must be cited in APA format 7th Edition, and must include minimum of 3 scholarly resources published within the past 5-7 years (not part of the classroom coursework).  

Florida

Purpose

The purpose of this assignment is to identify the scope of practice in one’s state, including level of independence of practice, prescribing authority, any limitations of practice, process for obtaining licensure in your state, certification, and education requirements for licensure.  Next, students will discuss how the level of independence of practice in their state, i.e., reduced, restricted or full practice, affects patients’ access to care in their local community.

Purpose

The purpose of this assignment is to identify the scope of practice in one’s state, including level of independence of practice, prescribing authority, any limitations of practice, process for obtaining licensure in your state, certification, and education requirements for licensure.  Next, students will discuss how the level of independence of practice in their state, i.e., reduced, restricted or full practice, affects patients’ access to care in their local community.

Activity Learning Outcomes

Through this discussion, the student will demonstrate the ability to: 

· Understand NP practice as defined by law (CO2) 

· Determine legislation as defined by legislation, statutes and regulations (CO2) 

· Identify barriers to ensuring patient’s rights (CO3) 

Due Date: Wednesday by 11:59 pm MST of Week 6

Initial responses to the discussion topic must be posted by Wednesday 11:59 pm MT. Two additional posts to peers and/or faculty are due by Sunday at 11:59 pm MT.  Students are expected to submit assignments by the time they are due.

 A 10% late penalty will be imposed for discussions posted after the deadline on Wednesday of week 6, regardless of the number of days late. NOTHING will be accepted after 11:59 pm MT on Sunday (i.e. student will receive an automatic 0). 

Total Points Possible: 100

Preparing the Discussion

Discuss your state NP community in terms of scope of practice. Include your state’s scope of practice for NPs, including: 
Florida

1.

· Level of independence of practice 
**In California, NPs are required to practice under Standardized Procedure Guidelines. If CA is your intended practice state, please provide details on how Standardized Procedures Guidelines are developed in California and an example of a California SPG.

· Prescribing authority 

· Any limitations of practice 

· Process for obtaining licensure in your state 

· Certification and education requirements for licensure. 

2. If you live in a restricted or reduced practice state, how has patient care been impacted in your local community by these barriers? For instance, is the ED used for primary care?  Are the EDs overcrowded with long wait times?  Are there urgent care clinics readily available? Is there adequate access to primary care?  If you live in a full practice, how has an independent practice of the APN resulted in improved patient access to healthcare?   

3. How does access to NPs impact any healthcare disparities?  

4. A scholarly resource must be used for EACH discussion question each week.

Florida

 Identify an article that is at least five years old. Summarize the statistical findings and discuss the significant it has on nursing.