Respiratory Assignment Answer

Respiratory Assignment Answer - which helps maintain a...

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Comments about the Respiratory Assignment Congratulations! You did very well with a challenging question. Most of you received the maximum score of 3 points. This is because (a) you understood at least most of the main concepts of the Williams, et al. hypothesis, and (b) I gave a score of 3 even if you answered one of the five questions wrong. My scoring scheme was: 4 or 5 correct answers = 3, 3 correct answers = 2, 1 or 2 correct answers = 1, and 0 correct answers = 0. Below are the answers I wanted for each question. Almost everyone answered 3, 4 & 5 correctly. Doug Wangensteen * * * * * * * * * * According the Williams, et al. paper: 1. BK channels in the glomus cell membrane are transporters for what ion? POTASSIUM That’s what the “K” stands for in the name of the channel. Many of you answered calcium but still received 3 points because you got the other four correct. 2. When the arterial P O2 is greater than 90-100 mmHg, some BK channels are open,
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Unformatted text preview: which helps maintain a normal (hyperpolarized) cell membrane potential. What is the chemical messenger that acts on BK channels to keep them open during normoxia? CARBON MONOXIDE (“It’s a Gas!”) This is one of the key concepts in the Williams, et al. hypothesis. Several of you thought it was calcium. 3. What molecule is the “oxygen sensor” that produces the chemical messenger? HEMOXYGENASE-2 (HO-2) 4. What happens to BK channels when the arterial P O2 decreases below 90-100 mm Hg? THE BK CHANNELS CLOSE; CO keeps them open when the P O2 is high enough. 5. What effect does the change in the BK channels due to decreased P O2 have on the glomus cell? THE MEMBRANE IS DEPOLARIZED (The answer I was looking for and which most of you gave.). Increased frequency of action potentials, influx of calcium ions or release of dopamine were also acceptable responses. Some of you listed all four....
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This note was uploaded on 02/20/2010 for the course PHSL 3061 taught by Professor Barnett during the Fall '08 term at Minnesota.

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