Nokea
Decompression sickness is caused by
- A. a rapid rise of carbon dioxide in the blood.
- B. lack of oxygen in the tissues
- C. bubbles of nitrogen in the blood
- D. glucose deficiency.
Correct Answer: C
Rationale: Decompression sickness occurs when nitrogen bubbles form in the blood due to rapid changes in pressure during ascent. Nitrogen, a major component of air, dissolves in the blood at higher pressure and forms bubbles when pressure decreases. These bubbles can block blood vessels, leading to various symptoms. Choice A is incorrect as it pertains to hypercapnia, not decompression sickness. Choice B is incorrect as decompression sickness is not caused by lack of oxygen but rather by nitrogen bubbles. Choice D is incorrect as glucose deficiency is not related to decompression sickness. Therefore, the correct answer is C, bubbles of nitrogen in the blood.
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Haldane effect refers to
- A. Increased CO2 uptake to minimize CO2 tension
- B. Increased O2 tension
- C. Decreased CO2 tension
- D. Decreases O2 tension
Correct Answer: A
Rationale: The correct answer is A: Increased CO2 uptake to minimize CO2 tension. The Haldane effect describes how the blood's ability to carry CO2 increases as oxygen levels decrease. When oxygen binds to hemoglobin, it displaces CO2, allowing more CO2 to be carried by the blood. This phenomenon is crucial in the exchange of gases in the lungs and tissues.
Choice B is incorrect as the Haldane effect is related to CO2, not O2 tension. Choice C is incorrect as the Haldane effect leads to increased CO2 uptake, not decreased. Choice D is incorrect as it states decreases O2 tension, which is not directly related to the Haldane effect.
The most abundant gas in the earth's atmosphere is
- A. oxygen.
- B. water vapor
- C. argon.
- D. nitrogen.
Correct Answer: D
Rationale: The correct answer is D: nitrogen. Nitrogen makes up about 78% of the Earth's atmosphere, making it the most abundant gas. This is due to the fact that nitrogen is a chemically stable element that forms diatomic molecules (N2) which are not easily broken down. Oxygen (A) makes up about 21% of the atmosphere, while water vapor (B) and argon (C) are present in much smaller quantities. Therefore, nitrogen is the most abundant gas in the Earth's atmosphere based on its high percentage composition.
While assessing an older adult patient, what finding indicates left-sided heart failure?
- A. Weight gain
- B. Ascites
- C. Crackles
- D. Jugular vein distention
Correct Answer: C
Rationale: The correct answer is C: Crackles. Crackles indicate left-sided heart failure due to fluid accumulation in the lungs. This occurs when the left side of the heart is unable to efficiently pump blood, leading to fluid backing up into the lungs. Weight gain (A) may be a general sign of heart failure but is not specific to left-sided failure. Ascites (B) is more indicative of right-sided heart failure, where fluid accumulates in the abdomen. Jugular vein distention (D) is a sign of right-sided heart failure, where blood backs up into the systemic circulation causing jugular vein distention.
Hiccup is due to
- A. Increased inspiration
- B. Irritation of Phrenic nerve
- C. Expanded stomach
- D. Acidity in the stomach
Correct Answer: B
Rationale: The correct answer is B because hiccups are caused by the irritation of the phrenic nerve, which controls the diaphragm muscle responsible for breathing. When the nerve is irritated, it causes the diaphragm to contract involuntarily, leading to the characteristic sound of hiccups.
Choice A (Increased inspiration) is incorrect as hiccups are not caused by increased inspiration but rather by involuntary contractions of the diaphragm.
Choice C (Expanded stomach) is incorrect as hiccups are not directly related to the size of the stomach but rather to nerve irritation.
Choice D (Acidity in the stomach) is incorrect as hiccups are not primarily caused by stomach acidity, but by nerve irritation leading to diaphragm contractions.
When does oxyhemoglobin form during respiration?
- A. during external respiration
- B. immediately after carbon dioxide enters the blood
- C. when the chloride shift occurs
- D. during pulmonary ventilation
Correct Answer: A
Rationale: The correct answer is A, during external respiration. Oxyhemoglobin forms when oxygen binds to hemoglobin in the lungs during external respiration. This process occurs in the alveoli where oxygen diffuses from the air sacs into the blood, binding with hemoglobin to form oxyhemoglobin. Choices B, C, and D are incorrect because oxyhemoglobin formation specifically happens during external respiration, not immediately after carbon dioxide enters the blood, when the chloride shift occurs, or during pulmonary ventilation. These processes are important in respiration but do not directly involve the formation of oxyhemoglobin.