3) What is the creatinine clearance test? How is it be used to estimate glomerular filtration rate?

1) Describe how CD8 T-cells contribute to cell-mediated immunity. [Be sure to provide a short general overview first, and then provide specific ways in which T cells destroy their target cells].

Which of the following statements about cardiac anatomy is CORRECT:

A. Papillary muscles contract to open the AV valves.

B. Cardiac cells in the SA node are functionally coupled by chemical synapses.

C. The heart does not have its own arteries, capillaries, and veins because it obtains vital substances from the blood that is being pumped through it.

D. The volume of the left ventricle is equal to the volume of the right ventricle.

*Option D is the correct answer, please explain why choice D is correct, and why choice A is incorrect! Thank you!

Acetylcholine stimulates an action potential in the muscle cell membrane by:

a) Opening chloride channels in the muscle cell membrane

b) Opening channels in the neuromuscular junction which allow sodium to move out of the cell

c) Opening channels in the neuromuscular junction which allow potassium to move out of the cell

d) Opening channels in the neuromuscular junction which allow sodium to move in and potassium to move out, though sodium moves faster than potassium because both chemical and electrical gradients drive sodium into the cell

e) Opening channels in the neuromuscular junction which allow sodium to move in and potassium to move out, though potassium moves faster than sodium because potassium is closer to equilibrium

Please provide an explanation. Thank you.

Which of the following is TRUE of the absolute refractory period?

a) It establishes the maximum frequency with which a nerve cell can conduct action potentials

b) It does not end until the Na+/K+ pump has restored the ions to their original locations

c) It establishes the maximum number of graded potentials that can summate

d) Two of the above are correct

d) a) b) and c) are correct

Please provide an explanation. Thank you.

You will provide a summary of the respiratory system from the perspective of inhaled air. Your description should include:

- An organized progression of travel. What organs does the air travel through? What types of tissues and structures are seen within them? What purposes do those structures serve?

- Orientation of those organs within the body using correct directional and regional terminology. For example - it is not adequate to say that air is inhaled via the nose, you should include a description of where the nose is found and where air will progress (i.e. Air is inhaled via the nares in the facial region, and progresses posterior through the nasal cavity towards the naso-pharynx.)

A young woman is snorkeling and (as an observant physiology student) you understand that she must increase her tidal volume and/or her breathing frequency to maintain her alveolar ventilation rate. Why?

What is the mechanism of gas exchange between alveoli and pulmonary capillaries? Compare the gas pressures in the pulmonary capillaries to the gas pressures in the alveoli, in a normal person at rest.

Should the Addictions be Treated with Pharmaceutical Agents? Although he is a physician, Breggin (2008) has long been a critic of the pharmaceutical industry. For example, he observed that “Drug companies heavily promote the unproven speculation that the problems they treat are biological in origin and result from biochemical imbalances.” This is, as he points out, an unproven hypothesis. It appears to be right, but sometimes the accepted theory is proven to be absolutely wrong. For example, 50 years ago every physician knew that stomach ulcers were caused by stress. The standard treatment was antacids and possibly tranquilizers. Now it is known that the vast majority of ulcers are caused by bacterial infections in the wall of the stomach and the standard treatment is a course of antibiotics and antacids to help the stomach lining heal. The “biochemical imbalance” is not automatically correct, it is just the most promising theory developed to date. However, nobody knows what a normal neurochemical balance in the brain actually is, much less how to achieve that balance. In spite of their “we’re here to help” public image, pharmaceutical companies want to sell you more pharmaceuticals so they make a profit (Breggin, 2008). Through media campaigns, they attempt to make physicians and the general public believe they need pharmaceuticals to deal with life’s problems. While this is not to dismiss the benefit of certain medications in the treatment of certain disorders (such as hypertension, for example), do we need medications to deal with all of life’s problems? People have found ways to cope with the problems of living for 10,000 generations before the rise of the pharmaceutical industry. Why do they suddenly need medications to cope? There is a rather interesting paradox inherent in the pharmaceutical treatment of a substance use disorder, in that we attempt to medicate hypothetical chemical imbalances in the brain, the exact nature of which we do not understand, with pharmaceuticals whose effects we also do not fully understand. It is important to keep in mind that although marketed as treatments for specific conditions, the psychopharmaceuticals have a blanket effect on the entire brain, not just the one subsystem that is hypothetically malfunctioning. As a result, other pharmaceutical agents are also used to treat various forms of mental illness side-effects such as drowsiness, ataxia, etc. Breggin (2008) suggested that some of psychopharmaceuticals in use today cause lifelong damage to the brain. The basic premise of psychopharmaceuticals is that they disrupt the function of the brain, hopefully in a more normal manner. The premise is the same for alcohol and for the drugs of abuse, although they usually seek euphoria. Surprisingly, from this perspective, it is possible to argue that the substance use disorders are attempts at self-medication by the abuser. However, we know so little about the normal function of the brain that neither the current generation of psychopharmaceuticals nor any of the drugs of abuse are able to selectively dampen the function of just one region of the brain (Breggin, 2008). The medications impair the function of every region of the brain to some degree, leaving the question of whether they have “cured” the disorder, or just immobilized it behind a chemical straight jacket, unanswered. These effects are “...then interpreted (or misinterpreted) as improvements” (Breggin, 2008, p. 1). When alcohol or illicit drugs are abused, the biochemistry of the individual’s entire brain is also affected, although it might only be observed in one domain of neurological function. Although the reader might question the relevance of this discussion to the addictions, it is important to remember that the substance use disorders (SUDs) have been classified as medical disorders. The pharmaceutical companies are searching for medications that can be used to treat the SUDs, and already existing medications are often being used “off label” to treat alcohol and illicit drug addiction. (Note: “Off label” is a term that refers to the application of a pharmaceutical to a disorder for which it has not been identified as an effective treatment by the FDA.)

1. Are treatments using the pharmaceutical agents described above an improvement over the damage drugs of abuse cause to the brain? Why or why not?

2 . Many patients neither want, nor will they accept, pharmacotherapy for their substance use disorders (Harris, Kivlahan, Bowe, & Humphreys, 2010). Imagine science discovers a compound that will eliminate the individual’s “craving” for alcohol or another drug of abuse with 100 percent certainty. Do we, as a society, have the right to force such treatments on a patient, even if they are effective? Who should be able to decide what medications an addict receives to help him or her escape from the addiction?

3.Are the SUDs medical disorders, behavioral disorders that affect the body (e.g., obesity), or a legal problem? Why? What implications does your answer have for how the disorder/problem is treated?

4.Do you believe that the SUDs should be treated with pharmaceutical agents? Why or why not?

What does VE/VCO2 and VE/VO2 mean?

Does anaerobic threshold occur at the same time as lactate threshold?