what is the role of the alveoli in the lungs

HESI A2

Quizlet HESI A2 Anatomy and Physiology

1. What is the role of the alveoli in the lungs?

A. To filter blood
B. To exchange gases
C. To transport nutrients
D. To store oxygen

Correct answer: B

Rationale: The alveoli in the lungs are tiny air sacs responsible for the exchange of oxygen and carbon dioxide during breathing. Oxygen from inhaled air diffuses into the bloodstream through the alveoli, while carbon dioxide produced by cells is removed from the blood and exhaled out of the body through the alveoli. This gas exchange process is essential for the body to obtain oxygen and get rid of carbon dioxide, supporting cellular functions and maintaining overall health. Choices A, C, and D are incorrect because the alveoli do not filter blood, transport nutrients, or store oxygen. Their main function is gas exchange.

2. Express the ratio of 25:80 as a percentage.

A. 31.25%
B. 34%
C. 41.25%
D. 43.75%

Correct answer: A

Rationale: To express the ratio 25:80 as a percentage, follow these steps: First, divide 25 by 80: 25/80 = 0.3125. Then, multiply by 100 to convert to a percentage: 0.3125 × 100 = 31.25%. Therefore, the ratio 25:80 is equivalent to 31.25%. Choice A is correct. Choice B (34%) is incorrect because it does not accurately represent the ratio 25:80. Choice C (41.25%) and Choice D (43.75%) are also incorrect as they do not match the calculated percentage for the given ratio.

3. Select the word that means 'on both sides.'

A. bilateral
B. insufficient
C. bicuspid
D. congruent

Correct answer: A

Rationale: The correct answer is 'bilateral.' 'Bilateral' means having two sides or affecting both sides. 'Insufficient' means not enough or inadequate, 'bicuspid' refers to a two-pointed tooth, and 'congruent' means in agreement or harmony. Therefore, 'bilateral' is the only word among the choices that specifically relates to being on both sides.

4. The formula for calculating ideal body weight (IBW) for men is IBW (kg) = 50 + 2.3 * (height in cm - 150). If a man is 180cm tall, what is his ideal body weight?

A. 68kg
B. 71kg
C. 74kg
D. 77kg

Correct answer: B

Rationale: Rationale: 1. Substitute the given height into the formula for calculating ideal body weight (IBW) for men: IBW (kg) = 50 + 2.3 * (180 - 150) IBW (kg) = 50 + 2.3 * 30 IBW (kg) = 50 + 69 IBW (kg) = 119 2. Therefore, the ideal body weight for a man who is 180cm tall is 119kg. 3. Among the given options, the closest value to 119kg is 71kg (option B). 4. Hence, the correct answer is B) 71kg.

5. Which of the following molecules is an important component of the plasma membrane?

A. Phospholipids
B. Steroids
C. Sugars
D. Amino acids

Correct answer: A

Rationale: Phospholipids are indeed a crucial component of the plasma membrane. They have a unique structure with hydrophilic heads and hydrophobic tails, which allows them to form the lipid bilayer of the membrane. Steroids, sugars, and amino acids are not primary components of the plasma membrane. Steroids are a different type of lipid, sugars are often found in glycoproteins on the membrane surface, and amino acids are the building blocks of proteins, some of which are membrane proteins, but not the membrane itself.