Nokea
Mammalian RBC respire anaerobically because
- A. It has stroma inside
- B. It has Haemoglobin
- C. It lacks Mitochondria
- D. It has bicarbonate ions inside
Correct Answer: C
Rationale: The correct answer is C because mammalian RBCs lack mitochondria, which are responsible for aerobic respiration. Without mitochondria, RBCs are unable to perform oxidative phosphorylation to generate ATP aerobically. Stroma (A) is found in chloroplasts, not RBCs. Hemoglobin (B) is responsible for oxygen transport, not cellular respiration. Bicarbonate ions (D) are involved in the buffering system of blood, not in cellular respiration. Therefore, the lack of mitochondria is the key reason for RBCs to respire anaerobically.
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A slightly obese female client with a history of allergy-induced asthma, hypertension, and mitral valve prolapse is admitted to an acute care facility for elective surgery. The nurse obtains a complete history and performs a thorough physical examination, paying special attention to the cardiovascular and respiratory systems. When percussing the client's chest wall, the nurse expects to elicit:
- A. Resonant sounds.
- B. Hyperresonant sounds.
- C. Dull sounds.
- D. Flat sounds.
Correct Answer: A
Rationale: The correct answer is A: Resonant sounds. Percussing the chest of a healthy individual typically elicits resonant sounds due to the presence of air-filled lung tissue. In this case, the client has a history of asthma, which indicates airway inflammation and possible mucus accumulation, making resonant sounds more likely. Hyperresonant sounds (B) are typically heard in conditions like emphysema with increased lung volume. Dull sounds (C) are indicative of fluid or solid tissue present in the lungs, which is not expected in this client. Flat sounds (D) are heard over areas of solid tissue or muscle, not in the chest of a client with respiratory conditions.
What is the function of the conchae in the nasal cavity?
- A. increase surface area
- B. exchange gases
- C. maintain surface tension
- D. maintain air pressure
Correct Answer: A
Rationale: The function of the conchae in the nasal cavity is to increase surface area. By increasing the surface area of the nasal cavity, conchae help to humidify, filter, and warm the air entering the respiratory system. This ensures optimal conditions for efficient gas exchange in the lungs. Choice B (exchange gases) is incorrect because gas exchange primarily occurs in the alveoli of the lungs, not in the nasal cavity. Choice C (maintain surface tension) is incorrect as surface tension is typically associated with liquid interfaces, not with the nasal cavity. Choice D (maintain air pressure) is also incorrect because the conchae do not play a direct role in maintaining air pressure within the nasal cavity.
What is the effect of carbonic anhydrase inhibition on the excretion of bicarbonate in the urine?
- A. Increased excretion
- B. Decreased excretion
- C. No effect on excretion
- D. Increased reabsorption
Correct Answer: A
Rationale: Carbonic anhydrase catalyzes the conversion of carbon dioxide and water to bicarbonate and hydrogen ions in the kidney. Inhibiting carbonic anhydrase reduces bicarbonate reabsorption, leading to increased excretion of bicarbonate in the urine. Therefore, the correct answer is A.
Incorrect choices:
B: Inhibiting carbonic anhydrase would decrease bicarbonate reabsorption, resulting in increased excretion, not decreased.
C: Inhibition of carbonic anhydrase does have an effect on bicarbonate excretion.
D: Inhibiting carbonic anhydrase would not increase reabsorption but rather decrease it, leading to increased excretion.
The pneumotaxic center of the pons
- A. sets the at-rest respiratory pattern
- B. prolongs inspiration
- C. modifies the rate and depth of breathing
- D. suppresses the expiratory center in the medulla
Correct Answer: C
Rationale: The correct answer is C because the pneumotaxic center in the pons modifies the rate and depth of breathing by sending inhibitory signals to the dorsal respiratory group in the medulla, which controls inspiration and expiration. It does not set the at-rest respiratory pattern like option A, prolong inspiration like option B, or suppress the expiratory center in the medulla like option D. This center plays a crucial role in fine-tuning breathing patterns to maintain appropriate oxygen levels in the body.
What keeps alveoli from collapsing?
- A. Carina
- B. Surfactant
- C. Empyema
- D. Thoracic cage
Correct Answer: B
Rationale: Surfactant is a substance that prevents the collapse of alveoli by reducing surface tension, allowing them to remain open and functional during the breathing process.