Nokea
All of the following states decrease lung compliance EXCEPT
- A. Lung fibrosis
- B. Increased pulmonary venous pressure
- C. Long period of time where the lung is unventilated
- D. Emphysema
Correct Answer: D
Rationale: The correct answer is D: Emphysema. Emphysema is characterized by destruction of lung tissue, leading to loss of elasticity and increased compliance. Increased compliance means the lungs are easier to expand, contrary to decreased compliance seen in the other conditions listed. Lung fibrosis, increased pulmonary venous pressure, and prolonged lung collapse all lead to decreased lung compliance by causing stiffness, fluid accumulation, and reduced lung expansion, respectively. Therefore, D is the correct answer as it does not decrease lung compliance.
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pharynx is a muscular tube with a length of
- A. 13cm
- B. 12cm
- C. Sinches
- D. both a and c
Correct Answer: A
Rationale: The correct answer is A: 13cm. The human pharynx is typically around 13cm in length. This length allows for the proper passage of food and liquids from the mouth to the esophagus. Choice B (12cm) is incorrect as it is slightly shorter than the average length of the pharynx. Choice C (5 inches) is also incorrect as it does not correspond to the standard unit of measurement for medical lengths. Choice D (both a and c) is incorrect as 12cm and 5 inches are not equivalent lengths for the pharynx.
Following an asthmatic attack, a mother asks the physician how to prevent another asthmatic attack. The physician should:
- A. Tell her that asthmatic attacks cannot be prevented.
- B. Help the mother identify triggers that cause asthmatic attacks and show her how to avoid them.
- C. Change her medication.
- D. Immediately move her family to a dry climate.
Correct Answer: B
Rationale: The correct answer is B. Identifying and avoiding triggers is key to preventing asthma attacks. A is incorrect because prevention is possible. C (changing medication) may help but is secondary. D (moving to a dry climate) is impractical and unnecessary.
Mammalian lungs have numerous alveoli for
- A. Increasing the volume of inspired air
- B. Keeping the lungs in proper shape
- C. Higher number of muscles to provide greater elasticity
- D. Increasing surface area for gaseous diffusion
Correct Answer: D
Rationale: The correct answer is D because alveoli increase the surface area for gaseous diffusion, facilitating efficient exchange of oxygen and carbon dioxide in the lungs. Alveoli are tiny air sacs where gas exchange occurs. Option A is incorrect as alveoli do not affect the volume of inspired air. Option B is incorrect as alveoli do not play a role in maintaining lung shape. Option C is incorrect as alveoli do not increase muscles in the lungs for elasticity. Therefore, the primary function of alveoli is to increase surface area for gaseous diffusion, making option D the correct choice.
Exhaling into a paper bag and rebreathing the exhaled air would be expected to
- A. alert the brain.
- B. increase the breathing rate.
- C. stimulate the carotid bodies.
- D. b and c only
Correct Answer: D
Rationale: Exhaling into a paper bag and rebreathing the exhaled air leads to an increase in carbon dioxide levels in the body. This increase stimulates the carotid bodies, which detect changes in blood chemistry, leading to an increase in breathing rate. This process does not directly alert the brain, as high carbon dioxide levels typically cause drowsiness rather than alertness. Therefore, the correct answer is D, as it correctly identifies the effects of rebreathing on both breathing rate and carotid body stimulation. Choice A is incorrect because rebreathing does not directly alert the brain. Choice B is incorrect as rebreathing actually decreases the need for increased breathing rate initially. Choice C alone is incorrect as it does not address the effect on breathing rate.
Which ion is formed as a result of the action of carbonic anhydrase on carbon dioxide and water?
- A. Sodium ion (Na+)
- B. Bicarbonate ion (HCO3-)
- C. Hydroxide ion (OH-)
- D. Potassium ion (K+)
Correct Answer: B
Rationale: Step 1: Carbonic anhydrase catalyzes the reaction between carbon dioxide (CO2) and water (H2O).
Step 2: This reaction forms carbonic acid (H2CO3).
Step 3: Carbonic acid then dissociates into bicarbonate ion (HCO3-) and hydrogen ion (H+).
Step 4: Therefore, the ion formed as a result of the action of carbonic anhydrase on CO2 and H2O is the bicarbonate ion (HCO3-).
Summary:
- Choice A (Sodium ion) is incorrect as it is not involved in the reaction with carbonic anhydrase.
- Choice C (Hydroxide ion) is incorrect as it is not a product of the reaction but rather a different compound.
- Choice D (Potassium ion) is incorrect as it is not related to the reaction between carbon dioxide and water.