Nokea
Exchange across a membrane requires
- A. moisture.
- B. transport proteins
- C. pressure gradients.
- D. all of the above
Correct Answer: D
Rationale: Exchange across a membrane involves the movement of molecules or ions. Moisture (A) helps facilitate this movement by dissolving solutes. Transport proteins (B) are essential for facilitating the movement of specific molecules across the membrane. Pressure gradients (C) can drive the movement of substances across the membrane. Therefore, the correct answer is D, as all these factors play a crucial role in facilitating exchange across a membrane. Moisture alone is not sufficient for exchange, transport proteins are necessary for specific molecule transport, and pressure gradients can aid in driving the movement of substances.
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Regarding oxygen transport
- A. The predominant way oxygen is transported in the blood is as dissolved oxygen
- B. 1 gram of pure Hb can combine with 1.34 - 1.39 ml of oxygen
- C. An anaemic patient has a lowered arterial pO2 because the Hb is low
- D. CO2 is 200 times more soluble than oxygen
Correct Answer: B
Rationale: The correct answer is B: 1 gram of pure Hb can combine with 1.34 - 1.39 ml of oxygen. This is correct because each gram of hemoglobin can bind with approximately 1.34 - 1.39 ml of oxygen, facilitating efficient oxygen transport in the blood.
A is incorrect because while a small amount of oxygen is transported as dissolved oxygen, the majority is transported bound to hemoglobin.
C is incorrect because arterial pO2 reflects the oxygen content in the blood, not just the hemoglobin levels.
D is incorrect because CO2 is actually 20 times more soluble than oxygen, not 200 times.
Which pressure remains negative throughout the respiratory cycle?
- A. intrapulmonary
- B. intrapleural
- C. intra-alveolar
- D. atmospheric
Correct Answer: B
Rationale: The correct answer is B: intrapleural pressure. Intrapleural pressure remains negative throughout the respiratory cycle due to the opposing forces of the elastic recoil of the lungs and the chest wall. This negative pressure keeps the lungs inflated and facilitates breathing. In contrast, intrapulmonary (A) and intra-alveolar (C) pressures fluctuate during inhalation and exhalation, becoming positive and negative, respectively. Atmospheric pressure (D) remains relatively constant and serves as the reference point for pressure changes in the respiratory system.
For a patient with advanced chronic obstructive pulmonary disease (COPD), which nursing action best promotes adequate gas exchange?
- A. Encouraging the patient to drink three glasses of fluid daily.
- B. Keeping the patient in semi-Fowler's position.
- C. Using a high-flow venturi mask to deliver oxygen as prescribed.
- D. Administering a sedative, as prescribed.
Correct Answer: C
Rationale: The correct answer is C: Using a high-flow venturi mask to deliver oxygen as prescribed. This is the best option as it directly addresses the issue of promoting adequate gas exchange in a patient with advanced COPD. The high-flow venturi mask delivers oxygen at a precise concentration, ensuring optimal oxygenation.
Encouraging the patient to drink fluids (A) is important for overall health but does not directly address gas exchange. Keeping the patient in semi-Fowler's position (B) can help with breathing but is not as effective as providing supplemental oxygen. Administering a sedative (D) can further depress the respiratory system and worsen gas exchange, making it an inappropriate choice.
Cloacal respiration is found in
- A. Snake
- B. Turtle and Tortoise
- C. Crocodile
- D. Frog
Correct Answer: B
Rationale: Cloacal respiration is found in turtles and tortoises. These reptiles can absorb oxygen through their cloaca, a multi-functional opening used for excretion and reproduction. Turtles and tortoises lack specialized respiratory organs like lungs, and thus utilize cloacal respiration as an additional means of obtaining oxygen. Snakes (Option A) primarily rely on lung respiration. Crocodiles (Option C) have well-developed lungs for breathing. Frogs (Option D) respire through their skin and lungs but do not utilize cloacal respiration like turtles and tortoises. Therefore, the correct answer is B, as it is the only species listed that exhibits cloacal respiration.
Carina is the point where ...... divided
- A. Trachea
- B. bronchi
- C. larynx
- D. none of them
Correct Answer: A
Rationale: The correct answer is A: Trachea. Carina is the point where the trachea is divided into the left and right primary bronchi. This anatomical landmark is located at the lower end of the trachea where it bifurcates into the bronchi. The other choices, B: bronchi and C: larynx, are incorrect because the trachea is the structure that is divided at the carina, not the bronchi or larynx. Choice D: none of them is also incorrect because the trachea is indeed divided at the carina. Therefore, the correct answer is A as it accurately describes the anatomical location where the trachea divides.