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Neuron Communication

What are Neurons?

Neurons are classified as nerve cells that receive and send electrical signals over long distances within the human body. A neuron receives electrical signals from the sensory neurons and other neurons. The neurons send electrical signals to motor neurons and to other neurons. The neuron that sends signals between the neurons is classified as the inter-neuron.

Sensory Neuron 

Inter Neuron

Motor Neuron

Neuron Structure:

Dendrite: receives stimulation from other neurons and sensory receptors, and conducts electrical messages to the neuron’s soma in order for the cell to properly function.

Nucleus: provides main energy needed in order for the nerve cell to function properly.

Soma (Cell Body): contains the nucleus and connects with the dendrites; it’s function is to form information received by the neuron’s dendrites.

Axon: a long cylindrical structure that carries and transmits the neuron’s information to different neurons, muscles, and glands.

Myelin Sheath: insulating layer (lipid substance) that surrounds the nerve cell’s axon; the myelin sheath increases the speed of electrical impulses that travel along the nerve cells.

Terminal Buttons: located at the end of the neuron; it’s main function is to send information to other neurons through the synapse.

Neuron Function: 

An electrochemical signal that occurs within a neuron is classified as Action Potential (nerve impulse). The direction of the nerve impulse is towards the axon terminals.

Action Potential is a rapid electrical charge that travels down a neuron’s axon. This nerve impulse is a result of positive ions (Na+ and K+) moving in and out of an axon.

Threshold occurs when a neuron reaches a certain level of stimulation required that will cause action potential to occur (starting a nerve impulse), and allowing a change in mV.

Stages of Action Potential 

1st Stage (Resting Potential): this is the first stage where there is a negative charge on the inside of the axon while the outside has more positive ions. The neuron has a charge of approximately -70 mV and is ready to start the process.

2nd Stage (Depolarization): this is the second stage where a message coming from the dendrites stimulates the section of the axon. Channels in the membrane allow the positive (Na+) ions to enter rapidly into the axon causing an increase in positive charge.

3rd Stage (Repolarization): this is the third stage where channels open that enable positive (K+) ions to exit out of the axon causing a decrease in positive charges; results in the charge returning to normal. The next section of the axon enters depolarization.

4th Stage (Flow of Depolarization): this is the fourth stage where positive ions (Na+ and K+) continue in a sequence of depolarization and repolarization. This causes the return to resting potential in order to begin a new cycle while AP continues to move down the axon.

The Insulated Neuron 

Glial Cells: cells that provide for the neuron with structural, nutritional, and other support. They do not produce electrical impulses and their job is to maintain homeostasis, form myelin, and provide support and protection for neurons.

Schwann Cells: cells that cover and wrap around the axon. They are the cells the produce myelin sheath around the axon; their job is to insulate the axon and produce faster electrical impulses.

Nodes of Ranvier: these are classified as the spaces between schwann cells. faster signal conduction occurs when the action potential jumps from Node to Node along the axon.

What is a Synapse? 

A synapse is classified as a structure (junction) that allows a neuron to pass an electrical or chemical signal to another neuron or to the target effector cell.

A synapse consists of: tips of terminal branches of axon, tiny space (gap) between neurons, and the ends of dendrites of the receiving neuron.

Axon Terminal Button: the axon terminal button’s primary functions are to produce neurotransmitters (NT), store neurotransmitters in synaptic vesicles, and recycle neurotransmitter building blocks.

Axon of Sending Neuron: conducts electrical impulses away from the neuron’s soma.

Synaptic Vesicle: vesicles that store neurotransmitters on the pre-synaptic side of the membrane.

Neurotransmitter: chemical messenger that carries, and maintains signals between neurons, or nerve cells, and other cells in the body.

Pre-Synaptic Membrane: the membrane that’s located on the end of an axon at a synapse that transmits neurotransmitters as a signal.

Synaptic Gap: space between two connecting neurons where neurotransmitters are released to transmit signals.

Post-Synaptic Membrane: the membrane that’s located on the axon terminal at the receiving neuron that receives signals through neurotransmitters.

Neurotransmitter Receptor: receptors that binds with neurotransmitters; in postsynaptic cells, neurotransmitter receptors receive signals that cause an electrical signal, by maintaining the activity of ion channels.

Dendrite of Receiving Axon: receive information from other neurons and transmit electrical stimulation to the soma; dendrites are covered with synapses.

Synapse Communication 

Action Potential: when action potential reaches the axon terminal; AP causes the synaptic vesicles to release the neurotransmitters into the synaptic gap. The neurotransmitters spread through the gap and bind to receptors on the receiving neuron.

The neurotransmitter messages are either received as excitatory or inhibitory. Efficient brain and nervous system function is based on proper balance of excitatory and inhibitory neurotransmitters.

Excitatory Neurotransmitters: stimulate the action potential on the receiving neuron. (Example: Acetylcholine). 

Inhibitory Neurotransmitters: represses the action potential on the receiving neuron. (Example: GABA). 

Action Potential will persist and the receiving neuron will produce AP if there is more excitatory neurotransmitters than inhibitory neurotransmitters.

Neurotransmitters in the synapse deactivate by enzymes and are reabsorbed by the axon terminal. This allows our nervous system to react at efficient moments rather than react at abnormal times.

Neurotransmitters fit into their receptors similar to a key in a lock, whereas other molecules don’t properly fit. Certain chemicals can interfere with the action of neurotransmitters. The neurotransmitters effect is based on the action of the receptor; the receptor could be Acetylcholine, Serotonin, or Dopamine.

Astronomy Wonder Post – Information Fluency

1. What questions did you need to research in order to research your topic? 

What are Exoplanets?

What methods are used to discover planets beyond our Solar System?

How many Exoplanets have been found?

Which methods are the hardest and which ones are the most resourceful?

Who was the first scientist to find an Exoplanet?

2. What new or familiar digital tools did you try to use as you worked through this project?

I used Topic Finder to help me find a detailed topic; Google to help me research the information; YouTube so I could find resourceful videos and embed them into my blog post; Citation Machine so I could cite my websites carefully and precise.

3. What was the process you used to investigate the topic? 

First, I found topics that interested me in astronomy, then I narrowed down my options to planets. I then found a topic about planets discovered beyond space and started researching more into it. Finally, I started my topic on “Exoplanets,” and began researching how scientists can discover these planets without being in space. I found many cool facts, information, and data about these planets. At the end, I went onto YouTube and found videos that explained further detail about my topic. Also, I cited all of my websites on Citation Machine so I could make sure my websites were proper, and had correct information.

4. How did you verify and cite the information you found?

To verify and cite the information I had found, I used Citation Machine and researched other websites to compare the information. I wanted to make sure these were correct facts about Exoplanets so there wouldn’t be any false information added into my blog post.

5. How did the process of completing this challenge go? What could you have done better? 

I think the majority of process to complete this blog post went well, except for a few minor setbacks. I had found my topic, and tried my best to make it interesting. I then got it checked, and started to research all of my information and questions on “Exoplanets.” When I had finished, I cited my websites and went on YouTube to find my videos. One thing I would have fixed about my project was to stop procrastinating. If we had more class time, and I used my days in class more wisely, I could have made my project more better. Also, I would have taken my time to make my project more visually creative, and detailed my images better. Overall, I think this assignment was very fun and would recommend this project for other teachers to give in science classes.

Astronomy Wonder Project

Question: How do scientists discover exoplanets outside of the solar system without physically being in space?

What are Exoplanets?

Exoplanets are planets that orbit stars beyond our Solar System. 

For many decades, scientists have been able to discover new planets outside of our Solar System. Technological advances in the workforce have increased findings to uncover unknown planets in space, and in other terms these are known as “exoplanets.”

The first exoplanet breakthrough was discovered in 1995 – when scientists found a planet in orbit around another star. Within 20 years, we have discovered more than 3,500 exoplanets beyond our Solar System. According to certain sources, there is more than one exoplanet for every star, which indicates that there are more exoplanets in the Milky Way than there are stars. Until 20 years ago, scientists assumed that they could only study planets that were found within the Solar System. Their main assumption was that other planets were beyond the Milky Way, but none were discovered and Scientists didn’t have the rights tools or methods to find them. Today in science, we know that there more than thousands of planets orbiting around other stars. They come in many different shapes and sizes, with different types of matter and chemicals. Some can be smaller than Earth, and bigger than planet Jupiter. Many exoplanets can be found around individual stars or in multiples systems. In the star systems, there can be singular or multiple planets orbiting around the star. 

Exoplanets are being discovered by scientists every day… but how are they finding them so easily, and what are their methods to finding these planets beyond our Solar System without being above earth, and in space? 

Scientists use a list of methods to find Exoplanets beyond our Milky Way. The most common methods used in the workforce are: The Transit Method, The Wobble Method, Direct Imaging, and Microlensing.

The Transit Method:

A solar eclipse is a type of transit. This occurs as the moon passes between the Sun and Earth. The Exoplanet Transits occurs when a distant planet passes between it’s Star and Earth. When a solar eclipse happens, the sun’s light goes from 100% to 0% as seen from people on earth, and goes back to 100% when the eclipse is over. When scientists observe distant stars in order to find transiting exoplanets, a star’s light might potentially dim by very little amounts or even smaller fractions of that size. The minute that the star is dim, it’s light can reveal a hidden planet. The dip in a star’s light is resourceful for uncovering exoplanets. To use this method, scientists/astronomers are required to develop sensitive instruments that can quantify the light shining from the star. Even when they looked for unknown planets for several decades, they couldn’t find any signs or evidence until the 1990’s. 

The Wobble Method (Also known as the radial velocity method): 

In all gravitational-bound systems that include stars, objects in orbit (a star and exoplanet) move around a known center of mass. When an exoplanet’s mass is significant to the star’s mass, there is a possibility for scientists to notice a wobble in the center. It would be detected by a shift in the star’s light frequencies. This shift is known as a Doppler shift. It has the same effect of a race car that makes the sound of a vroom – high-pitched coming towards you, and low-pitched when the car races away. When astronomers measure cyclic changes within the light spectrum of the star, they suspect that there is a large exoplanet orbiting around the star. The wobble method is specifically only used for finding very large exoplanets. Planets such as Earth, would not be detected because it’s too small to be measured by these tools. 

Direct Imaging: 

Direct Imaging is the most hardest and restricted method to use when trying to discover exoplanets beyond the system. First, the star has to be extremely close to Earth in order to track the planet, Also, the exoplanets in this specific system have to be far enough from the star so they can identify the planet from the star’s light. Scientists are required to use a special instrument called a “coronagraph,” so they can block the light from the star. This helps them reveal any dim light of a planet that could be orbiting around the star. Around 10-30 exoplanets have been discovered using this method. 

Microlensing:

The Microlensing method is another difficult tool that scientists use for finding exoplanets. In order to discover exoplanets using this method, one star needs to pass in front of another star that is more distant from Earth. Scientists could then possibly measure the light from the distance star that is passing the system. They can then observe differences between the star and its exoplanet. This method can work even if the exoplanet is very distant from its star. This becomes an advantage over the more common methods such as the Transit or Wobble Methods. 

In conclusion to this topic, scientists have help researching planets beyond our Solar System by using common methods to figure out differences between a star, and the planet orbiting around it. The most common methods are the Transit and Wobble methods while the uncommon ones are the Microlensing and Direct Imaging methods. This project helped me understand how scientists are able to research, observe, and discover new planets every day.

 

 

Citations:

Earthsky.org. (2017). How do astronomers find exoplanets?. [online] Available at: http://earthsky.org/space/how-do-astronomers-discoverexoplanets [Accessed 4 Jun. 2018].

sciencenordic.com. (2018). How do scientists find new planets?. [online] Available at: http://sciencenordic.com/how-do-you-find-new-planet [Accessed 4 Jun. 2018].

Encyclopedia Britannica. (2018). Extrasolar planet | astronomy. [online] Available at: https://www.britannica.com/science/extrasolar-planet [Accessed 4 Jun. 2018].

Government Responsibility Paragraph

Do you think that governments today should be held responsible for decisions and actions taken by previous governments?

There are many people that believe the governments today should be held responsible for the actions and decisions of previous governments, but other people oppose.

If I were to take the argument side of agreeing that governments should be held responsible, I would say yes. Governments from previous years were playing sides of racism, discrimination, and assimilation. They would convert Aboriginal peoples into the European culture. The residential schools were built to hurt the children, so they would be scarred enough to change their culture, language, and traditions. For many years, the government was built on trust for making Canada safe, proud, and diverse. By doing these acts, they should take full responsibility for previous acts, showing that these modern governments show empathy to the First Nations peoples by apologising and caring with remorse. For most purposes of the government, they would need to have proof of sympathy and awareness. The governments are apologizing for settlement and reimbursement against the past governments trying to make the country right again. I believe the government should take on the responsibility to help maintain liable status within the system, and help the country stay aware of the past problems we had, showing the steps Canada took in the future to make our population diverse, multicultural, and safe for all tribes, religion, culture, and status.

If I were to take the counter argumentative side, I would say no, the government was not responsible for the actions and decisions of previous governments. These acts were created and formed long ago but weren’t produced by our modern government. The residential school systems ended in 1996, showing that after this year, no new government should be held responsible for the crimes committed against them. When the decade of 2000s came, people started realizing severe fate and consequence, if our population wouldn’t show empathy to people of different status, culture, and tribe. The government would become more and more aware of these problems that continue in some parts of the country. I believe that there should be some aspects of awareness still within the government, but they wouldn’t need a formal apology to make things right for the Aboriginals. What’s done is done, and the government system changed immensely. We now believe to be multicultural and welcoming to all religions who enter/live in Canada. I believe that the government shouldn’t take on the responsibility of previous governments because of the changes that have been made over the years. This already shows acts of compassion, awareness, and care for the Aboriginals.

If I were to pick a side, choosing whether the government should take full responsibility or not, I would say yes. Even though, our modern governments haven’t done anything to hurt the Aboriginal peoples in any way, they still deserve a continuous apology to make up for what the previous governments did. It would also be right to make people aware of what happened in the past, and to help kids learn the incidents and act in school so the future won’t end up racially impacted by upcoming generations. The government doesn’t need it to be formal, but they should at least apologize once a year and have a day to remember the lives lost, and the one’s who fought against the act and won. The one’s who survived the schools should be remembered by everyone in Canada for staying strong throughout everything. I believe it would be right for the government to be responsible for previous governments because of the impactful and positive change shown in Canada throughout the years and past decade.

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