How would you relate association and causation?

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Instructions
Please answer the following questions in your own words to the best of your understanding. If you find evidence that is not from the Gordis text, please cite it in APA Style.
1. An investigator examined cases of fetal death in 27,000 pregnancies and classified mothers according to whether they had experienced sexual intercourse within 1 month before delivery. It was found that 11% of the mothers of fetuses that died and 2.5% of the mothers of fetuses that survived had had sexual intercourse during the period. It was concluded that intercourse during the month preceding delivery caused the fetal deaths. What guideline(s) did this researcher fail to take into account? Why is the conclusion reached by the investigator incorrect? (3 pts)\
1. How would you relate association and causation? Are these terms the same thing? (3 pts)
1. How could an epidemiological study prove causation? Other than the examples in the book, can you discuss another example of how an epidemiological study proved causation? (3 pts)
1. Give examples of indirect and direct causation associated with experiences in everyday life. (3 pts)
1. Give an example of a time you experienced what you thought was causation, but turned out to be confounding. This could be an event that has happened to you or a news story that demonstrated confounding. (3 pts)
Please remember to number your responses appropriately.

An Organ Systems

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An Organ Systems
The human body is truly remarkable and is designed to function effectively. Organs are important structures composed of different tissues that facilitate specific functions within the body. Organs function as part of an integrated group of structures known as organ systems. These organ systems form the organizational units that are responsible for crucial processes necessary for sustaining life. Examples of organ systems include, but are not limited to, the cardiovascular system, the digestive system, the musculoskeletal system, the nervous system, the excretory system, the endocrine system, and the respiratory system. Even organ systems do not function alone. These systems work together, interacting with other organs in a functional network that keeps the body in balance. (Look up the term homeostasis in your text.) When homeostasis or the normal functioning of organ systems is disrupted, disease may develop, causing injury to the body or even death.
The following case studies detail an outcome associated with a disease or organ malfunction. Select 1 study to investigate further for your assignment.
Critically evaluate the information provided, and correlate it with the organ systems that are affected in the scenario. Use the information that you have gathered to answer the assignment questions that follow the case study. Present your work as an APA-formatted research report.
Recommended: In addition to the case studies, click on the following links to view materials to increase your understanding and enhance your analysis of the cardiovascular and respiratory systems.
How Your Body is Like a Factory
How Lungs Work
Cardiovascular System
Case Study 1:
Atherosclerosis is narrowing of the arteries caused by the accumulation of fatty deposits on the arterial walls. On June 22, 2002, the St. Louis Cardinals were preparing for their upcoming baseball game against the Chicago Cubs. Concern arose when their prized pitcher, 33-year old Darryl Kile did not show up for practice. Soon after, he was found still in his hotel room where he had suddenly died in his sleep (New York Times, 2002). It was discovered that the cause of death was related to three of his coronary arteries being 80–90% blocked as a result of atherosclerosis (New York Times, 2002), which ultimately caused him to suffer a heart attack.
Answer the following questions in regard to this case study:

  • Why would atherosclerosis result in a heart attack? Provide a brief explanation based on how the heart functions.
  • How are arteries different from veins and capillaries? Describe the functions of both arteries and veins.
  • Vertebrates and some invertebrates have a closed circulatory system. Explain the advantage of having a closed circulatory system over an open circulatory system

Case Study 2:
Cigarette smoking remains the leading preventable cause of death in the United States, causing an estimated 438,000 deaths—or about 1 out of every 5 smokers—each year (National Cancer Institute, 2008).
Mr. Amos is 57 years old and has been smoking for the past 30 years of his life. A recent doctor’s visit revealed that Mr. Amos has stage 3 lung cancer, characterized by his symptoms of nagging chest pain, fatigue, coughing up blood, substantial weight loss, and increased carbon dioxide levels in his blood. The doctor informed Mr. Amos that had he quit his smoking habit several years ago, he would have reduced his risk for developing lung cancer later in life. Mr. Amos immediately began treatment for the lung cancer that had metastasized to his lymph nodes.
Answer the following questions regarding this case study:

  • What main components in cigarettes affect the respiratory system? Explain their effects on specific organs, cells, and processes in the respiratory system.
  • There are alternate mechanisms of transporting carbon dioxide (CO2) and oxygen (O2) in the blood. Explain how smoking might lead to increased levels of carbon dioxide in the blood.
  • Can smoking affect other organ systems of the body? Give specific examples, and briefly explain your answer.

Follow these guidelines for your paper:

  • Utilize at least 2 credible sources to support the arguments presented in the paper. Make sure you cite them appropriately within your paper, and list the references in APA format on your Reference page.
  • Your paper should be 2–3 pages in length, not counting the Title page, Abstract, and Reference page. In accordance with APA formatting requirements, it should be double-spaced and include a running head and page numbers.

References
American Lung Association. (2018). How lungs work. Retrieved from http://www.lung.org/lung-health-and-diseases/how-lungs-work/
The Franklin Institute. (2017). How your body is like a factory. Retrieved from https://www.fi.edu/heart/how-you-body-is-like-a-factory
Taylor, T. (2018). Cardiovascular system. Retrieved from http://www.innerbody.com/image/cardov.html

Antibiotic Resistance

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Antibiotic Resistance
For many years, antibiotics have been effectively used to treat bacterial disease.
A growing concern for treating bacterial diseases is the evolution of antibiotic resistance by bacterial populations. Resistance means that a particular antibiotic is no longer effective in treating a disease. This resistance can be viewed as evolution of a new trait at the population level, which is resistance to an antibiotic.
Recommended: Click on the following links to review materials to increase your understanding of natural selection and antibiotic resistance.
Understanding Evolution
Antibiotic Resistance
Focus your discussion on 1 of the following topics:

  • The use, overuse, and abuse of antibiotics are accredited with creating antibiotic-resistant strains of bacteria. Explain how this relates to natural selection.
  • Using a credible source, describe at least 2 of the things that people do (you can include individuals, doctors, health care professionals, hospitals, farmers, and so on) that contribute to this problem. Explain.
  • Are there things that you can personally do to reduce your risk or even to reduce the spread of these dangerous microbes?

Utilize at least 1 credible source to support the arguments presented in your post.
In your own words, post a response to the Discussion Board, and comment on at least 2 other postings. You will be graded on both level of engagement and the quality of the contribution to the discussion.
References
Centers for Disease Control and Prevention. (n.d.). About antibiotic use and resistance. Retrieved from https://www.cdc.gov/antibiotic-use/community/about/index.html
University of California Museum of Paleontology. (n.d.). Understanding evolution. Retrieved from https://evolution.berkeley.edu/evolibrary/home.php

Human Anatomy and Physiology

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Page 1“Bad Fish: Human Anatomy and Physiology Edition” by James A. Hewlett
NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
by James A. Hewlett Science and Technology Department Finger Lakes Community College
Bad Fish: Human Anatomy and Physiology Edition
Part I – Poisoned! One evening during a recent trip to Indonesia, Dr. Marshall Westwood from the Montana Technical Institute sat down to a meal of puff erfi sh and rice. Within an hour of returning to his hotel room, Dr. Westwood felt numbness in his lips and tongue, which quickly spread to his face and neck. Before he could call the front desk, he began to feel pains in his stomach and throat, which produced feelings of nausea and eventually severe vomiting.
Fearing that he had eaten some “bad fi sh” for dinner, Dr. Westwood called a local hospital to describe his condition. Th e numbness in his lips and face made it almost impossible for him to communicate, but the hospital staff managed to at least understand the address he gave them and they sent an ambulance in response. As Dr. Westwood was rushed to the hospital, his breathing became increasingly diffi cult.
Doctor’s Notes Th e patient presented in the ED with severe headache, diaphoresis, motor dysfunction, paresthesias, nausea, and an ascending paralysis that spread to the upper body, arms, face, and head. Th e patient was cyanotic and was hypoventilating. Within 30 minutes of presenting in the ED, Dr. Westwood developed bradycardia with a BP of 90/50. Atropine was administered in response to the bradycardia. IV hydration, gastric lavage, and activated charcoal followed a presumptive diagnosis of tetrodotoxin poisoning based on the clinical presentation in the ED. Five hours after intervention, the following vitals were noted:
• BP 125/79 • HR 78bpm • Oxygen saturation: 97% on room air
Follow-up Within a few hours, Dr. Westwood’s condition improved and he was on his way to a full recovery. After discussing his case with his physician, he learned that he had probably been the victim of a puff erfi sh poisoning. Th e active toxin in the tissues of this fi sh is a chemical called tetrodotoxin. Tetrodotoxin is in a class of chemicals known as neurotoxins due to the fact that it has its eff ects on nerve cells (neurons). Specifi cally, tetrodotoxin blocks voltage-gated sodium ion channels on neurons.
Questions 1. Present the “Doctor’s Notes” portion of the case with a description of the following terms or concepts:
• diaphoresis • motor dysfunction
NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Page 2“Bad Fish: Human Anatomy and Physiology Edition” by James A. Hewlett
• paresthesias • cyanotic • hypoventilating • bradycardia • gastric lavage • oxygen saturation
2. How many diff erent elements are contained in a molecule of tetrodotoxin? What are the names of these elements?
3. What type of chemical bonds are found in this molecule? Describe the structure of those bonds. 4. As mentioned in the case description, tetrodotoxin is a molecule that blocks voltage-gated sodium ion channels.
Describe the structure of a sodium ion. 5. What is a voltage-gated sodium ion channel? What is it made of? What is its function? 6. Why do sodium ions need channels in order to move into and out of cells? 7. Describe the process involved in the movement of ions through these channels. 8. When nerve cells are at rest, there is an unequal amount of positive and negative charges on either side of a
nerve cell membrane. Th is charge diff erence is called an electrical potential. Describe this “potential” when the neuron is at rest (resting potential).
9. What is happening to the electrical potential of a neuron when it generates an action potential? What is the function of the action potential in neurons?
10. Describe the role of sodium ions and sodium channels in the action potential. 11. What would happen to a neuron if it were exposed to tetrodotoxin? Be specifi c regarding its eff ect on the ability
of a neuron to communicate. 12. Now that you have addressed some of the basic biology of this case, explain why Dr. Westwood experienced
numbness after eating the puff erfi sh meal. 13. Paralysis is a term used to describe the loss of function of muscle. If tetrodotoxin’s eff ect is on neurons, why did
Dr. Westwood experience paralysis? 14. Explain how tetrodotoxin is involved in the development of hypotension and hypoventilation. 15. Briefl y describe the role of the autonomic nervous system in human physiology. What are the two divisions of
this system? 16. Atropine was administered in the ED as part of Dr. Westwood’s care. What eff ect did it have on his vitals after
it was administered? Atropine acts as an antagonist within the central nervous system, which means it acts as a blocker of specifi c cellular functions. What part of the autonomic nervous system does atropine block to produce its eff ect on Dr. Westwood?
NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Page 3“Bad Fish: Human Anatomy and Physiology Edition” by James A. Hewlett
Part II – Oh No! Not Again After recovering from his TTX poisoning, Dr. Marshall Westwood decided to take a vacation. An avid birder, he decided to go to Papua New Guinea with Bill Whitlatch, an ornithologist friend of his from Montana Technical Institute.
Th ree days into their trip, Bill netted bird with an orange body and black wings and head for closer study. Dr Westwood was very curious and asked Bill if he could have a closer look at the bird. After handling the bird and then later wiping his mouth with his hand, Dr. Westwood noticed that his fi ngers and lips were going numb. His mind immediately fl ashed back to the disastrous trip to Indonesia and he began to panic. Luckily, the symptoms faded before they progressed into anything more serious.
His friend Bill used a key to identify the animal as a pitohui. Th e pitohui are small, social songbirds that live in Papua New Guinea. Th ey are generally about 23 centimeters long with strong legs and a powerful beak. Th eir encounter was the fi rst time anyone had scientifi cally realized the birds’ toxicity.
Before releasing the bird, Dr. Westwood collected feather and tissue samples to bring back to the lab. After returning to Montana, he set out to isolate the toxic compound that he believed was being produced by the pitohui. It appeared that the active ingredient was a homobatrachotoxin. Homobatrachotoxin is a steroidal alkaloid that is similar to batrachotoxin, the toxic principle of the Central American poison arrow frog Phyllobates aurotaenia. Batrachotoxin and homobatrachotoxin are both known to act on the voltage-sensitive sodium channels in excitable tissues.
You and your colleagues received a call from Dr. Westwood asking if you could help elucidate the mechanism of action of this toxic compound. One of the hypotheses is that this toxin acts similarly to TTX.
Questions 17. In your fi rst experiment, you generated action potentials in axons of large neurons obtained from squid in the
presence of this new toxin. You found that after depolarizing, the membrane potential remained positive for an extended length of time, and the repolarization was often extremely delayed. Draw a graph (membrane potential in mV vs. time) to illustrate this eff ect.
18. As you continued to experiment with higher concentrations of the toxin, you found cases when the cell could not repolarize at all, or if it began to repolarize, it would immediately depolarize again. Using this description and the description in the previous question, describe how this toxin acts on voltage-gated sodium ion channels.
NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE
Page 4“Bad Fish: Human Anatomy and Physiology Edition” by James A. Hewlett
Image credits: Photograph on page 1, Arothron meleagris, © John E. Randall. Used with permission. Photograph on page 3, Hooded Pitohui, Jack Dumbacher. Courtesy of the Smithsonian National Museum of Natural History.
Case copyright held by the National Center for Case Study Teaching in Science, University at Buff alo, State University of New York. Originally published April 13, 2003. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.
Part III – Pharmacology In this section, you (or your group) will become a small pharmaceutical company that is trying to develop a drug that can be used in the ED to treat tetrodotoxin poisoning. Th ere is no antidote to tetrodotoxin poisoning. Th erefore, it is extremely important that your company is successful in this endeavor. In your report, you need to include the following:
• Your Company Name: o What do you want to call your company? Be creative!
• Name of Your Drug: • Treatment of:
o What does your drug treat? o What other diseases, problems etc. might it be useful for?
• Mechanism of Action: o Describe how your drug will work. o Be sure to provide details regarding its action. You are now familiar with the activity of this toxin at the
level of molecules and cells, so your description should contain details of how your drug works at that level.
• Dosage Form: o How will it be administered to patients?
• Side Eff ects: o What type of side eff ects might your drug have?
Some of your information will come from your understanding of what tetrodotoxin does to neurons. Th ere is no right or wrong answer to how your drug will work because there currently is no drug to treat this problem.
After you decide how your drug might work, you should consider if its mechanism would lead to side eff ects. In addition, your drug may be useful for other problems related to nerve function. You may want to do some research on drugs that have actions at neurons (specifi cally sodium ion channels) and diseases that involve sodium ion channels. Th is will help you develop your drug.

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