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. Which lobe of the brain is primarily responsible for auditory functioning?

A. Frontal lobe
B. Temporal lobe
C. Occipital lobe
D. Parietal lobe

Correct answer: B

Rationale: The correct answer is B: Temporal lobe. The temporal lobe of the brain is primarily responsible for processing auditory information, including sound perception, speech recognition, and language comprehension. Damage to the temporal lobe can lead to difficulties in hearing, understanding spoken language, and recognizing familiar sounds. Choices A, C, and D are incorrect because the frontal lobe is mainly associated with functions such as decision-making and personality, the occipital lobe is primarily responsible for processing visual information, and the parietal lobe is involved in sensory functions and spatial processing, not auditory functioning.

3. Which of the following is not part of the body’s secondary defense system?

A. Macrophages
B. Leukocytes
C. T cells
D. Cilia

Correct answer: D

Rationale: Cilia are not part of the body's secondary defense system. They are hair-like structures primarily involved in movement and transporting substances across cell surfaces, such as in the respiratory tract for debris and pathogen removal. However, cilia do not play a direct role in the immune response mechanisms characteristic of the body's secondary defense system. Macrophages, leukocytes, and T cells are immune cells that actively participate in the secondary defense system by targeting and eliminating pathogens.

4. Which organ is responsible for filtering and cleaning the blood?

A. Lungs
B. Heart
C. Kidneys
D. Liver

Correct answer: C

Rationale: The correct answer is C: Kidneys. The kidneys are the organs responsible for filtering and cleaning the blood. They remove waste products, regulate electrolyte levels, and help maintain fluid balance in the body through the production of urine. The other choices are incorrect because: A) Lungs are primarily responsible for gas exchange, not blood filtration. B) The heart is responsible for pumping blood, not filtering it. D) The liver plays a role in detoxification and metabolism, but it is not primarily responsible for filtering and cleaning the blood.

5. Which hormone is released by the adrenal medulla?

A. Cortisol
B. Adrenaline
C. Insulin
D. Somatostatin

Correct answer: B

Rationale: The correct answer is B, Adrenaline (also known as epinephrine), which is released by the adrenal medulla during the body's fight-or-flight response. Adrenaline helps prepare the body for action by increasing heart rate, dilating air passages, and mobilizing glucose and fats for energy, among other physiological responses. Choice A, Cortisol, is a steroid hormone released by the adrenal cortex involved in the stress response and regulation of metabolism. Choice C, Insulin, is produced by the pancreas and regulates blood sugar levels. Choice D, Somatostatin, is a hormone that inhibits the release of several other hormones in the body, but it is not released by the adrenal medulla.