which structure in the ear is responsible for hearing

HESI A2

Anatomy and Physiology Hesi A2 Practice Test

1. Which structure in the ear is responsible for hearing?

A. Cochlea
B. Semicircular canals
C. Ossicles
D. Eustachian tube

Correct answer: A

Rationale: The cochlea, located in the inner ear, is responsible for detecting sound waves and converting them into neural signals that are sent to the brain for processing. It plays a crucial role in the process of hearing by translating mechanical vibrations into electrical signals that the brain can interpret as sound. The semicircular canals (Choice B) are responsible for balance and detecting head movements, not hearing. The ossicles (Choice C) are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the cochlea. The Eustachian tube (Choice D) helps equalize pressure between the middle ear and the atmosphere, but it is not directly involved in the process of hearing.

2. 15\25 + 42\52 = ?

A. 1 3/10
B. 1 1/10
C. 1\10\2024
D. 3\10\2024

Correct answer: A

Rationale: 15\25 + 42\52 simplifies to 1 3\10.

3. A patient's temperature is 98.6 degrees Fahrenheit. What is their temperature in degrees Celsius (1°F = 5/9°C)?

A. 37�C
B. 32�C
C. 41�C
D. 45�C

Correct answer: A

Rationale: To convert Fahrenheit to Celsius, you need to subtract 32 from the Fahrenheit temperature (98.6°F) and then multiply the result by 5/9. Doing this calculation, you get 37°C. Choice B (32°C) is incorrect because it doesn't consider the conversion formula correctly. Choices C (41°C) and D (45°C) are incorrect as they do not apply the conversion formula accurately, leading to incorrect results.

4. A nurse is reviewing the daily intake and output (I&O) of a patient consuming a clear diet. The drainage bag denotes a total of 1,000 mL for the past 24 hours. The total intake is: 2 8oz cups of coffee, 1 16-oz serving of clear soup, and 1 pint of water consumed throughout the day. How much is the deficit in milliliters?

A. 440 mL
B. 500 mL
C. 480 mL
D. 300 mL

Correct answer: A

Rationale: First, convert all fluid intake to milliliters: 2 8-oz cups of coffee = 8 × 2 × 30 = 480 mL 1 16-oz serving of clear soup = 16 × 30 = 480 mL 1 pint of water = 16 × 30 = 480 mL Total intake = 480 + 480 + 480 = 1440 mL. The patient produced 1,000 mL, so the deficit is: 1440 mL - 1000 mL = 440 mL. Therefore, the deficit in milliliters is 440 mL. Choice A is correct. Choices B, C, and D are incorrect as they do not reflect the accurate deficit calculated based on the total intake and output provided in the question.

5. A doctor orders 1 gram of a medication to be administered intravenously. The available vial contains 200 milligrams per milliliter. How many milliliters of the solution should be drawn up?

A. 4 milliliters
B. 5 milliliters
C. 10 milliliters
D. 20 milliliters

Correct answer: B

Rationale: 1 gram is equivalent to 1000 milligrams. The concentration of the medication is 200 milligrams per milliliter. To calculate the volume needed, divide the total amount of medication by the concentration: 1000 mg / 200 mg/mL = 5 mL. Therefore, 5 milliliters of the solution should be drawn up to administer 1 gram of the medication intravenously. Choice A (4 milliliters), Choice C (10 milliliters), and Choice D (20 milliliters) are incorrect because they do not accurately calculate the volume of the solution needed based on the concentration of the medication.