which structure in the ear is responsible for balance

HESI A2

Anatomy HESI A2 Practice Test

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

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

Correct answer: B

Rationale: The semicircular canals in the inner ear are responsible for maintaining balance by detecting changes in head position and movement. These structures contain fluid and hair cells that send signals to the brain regarding the body's orientation in space, helping us stay balanced and navigate our surroundings. The cochlea is responsible for hearing, the ossicles are involved in sound transmission, and the Eustachian tube helps equalize pressure in the middle ear, but they are not directly related to balance.

2. What substance makes up the pads that provide support between the vertebrae?

A. bone
B. cartilage
C. tendon
D. fat

Correct answer: B

Rationale: Cartilage is the correct answer as it is the substance that makes up the pads between the vertebrae. Cartilage provides cushioning and support between the bones of the spine, allowing for flexibility and preventing friction between the vertebrae. Bone (choice A) is incorrect as it forms the structure of the vertebrae, not the intervertebral discs. Tendon (choice C) is incorrect as it connects muscle to bone and is not found between the vertebrae. Fat (choice D) is incorrect as it is not the substance that makes up the pads between the vertebrae.

3. What is the function of the urinary bladder?

A. To filter waste from the blood
B. To store urine
C. To regulate fluid balance
D. To remove waste from the body

Correct answer: B

Rationale: The correct answer is B: To store urine. The urinary bladder's primary function is to store urine produced by the kidneys until it is ready to be excreted from the body. It acts as a reservoir that temporarily holds urine until an appropriate time for elimination. Choices A, C, and D are incorrect because the urinary bladder does not filter waste from the blood, regulate fluid balance, or directly remove waste from the body. These functions are primarily carried out by the kidneys and other organs in the excretory system.

4. What is the primary function of the respiratory system?

A. To absorb oxygen
B. To transport nutrients
C. To produce sound and speech
D. To regulate blood pressure

Correct answer: A

Rationale: The primary function of the respiratory system is to absorb oxygen from the air into the bloodstream and expel carbon dioxide from the body. This process is essential for cellular respiration and the production of energy in the body. Option A, 'To absorb oxygen,' aligns with this crucial function, making it the correct choice. Choices B, C, and D are incorrect as they do not represent the primary function of the respiratory system. The respiratory system is not responsible for transporting nutrients (choice B), producing sound and speech (choice C), or regulating blood pressure (choice D).

5. What is the role of the spleen in the immune system?

A. To filter blood and remove old red blood cells
B. To produce white blood cells
C. To store lymphocytes
D. To produce antibodies

Correct answer: A

Rationale: The spleen plays a crucial role in the immune system by filtering blood, specifically removing old or damaged red blood cells. It also stores lymphocytes, which are white blood cells that help fight infections. While the spleen does not produce white blood cells or antibodies, its main functions lie in blood filtration and storage of immune cells. Therefore, the correct answer is A. Choice B is incorrect because the spleen does not produce white blood cells. Choice C is incorrect as the spleen stores lymphocytes but does not primarily function to do so. Choice D is incorrect because the spleen does not produce antibodies.