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. The corpus callosum facilitates communication between which brain structures?

A. the left and right brain
B. the skeletal and neural systems
C. the brain and spinal cord
D. the thalamus and hypothalamus

Correct answer: A

Rationale: The corpus callosum is a structure in the brain that enables communication between the two hemispheres. It allows for the transfer of various types of information, such as motor, sensory, and cognitive, between the left and right brain hemispheres, aiding in overall brain function and integration of tasks. Choices B, C, and D are incorrect as they do not involve the specific brain structures connected by the corpus callosum.

3. Which of the following endocrine system glands releases the thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones?

A. Thymus
B. Pituitary gland
C. Pineal gland
D. Hypothalamus

Correct answer: D

Rationale: The correct answer is D, the Hypothalamus. The hypothalamus is responsible for releasing various essential hormones, including thyrotrophic-releasing hormone, growth hormone-releasing hormone, and gonadotropin-releasing hormones. These hormones play crucial roles in regulating the functions of other endocrine glands by stimulating or inhibiting their hormone production. The Thymus (choice A) is primarily involved in the immune system, the Pituitary gland (choice B) secretes various hormones but not the ones specified in the question, and the Pineal gland (choice C) mainly produces melatonin, which regulates sleep-wake cycles, and is not related to the hormones mentioned in the question.

4. What is the function of the large intestine in the digestive system?

A. To secrete digestive enzymes
B. To absorb water and form solid waste
C. To produce bile
D. To transport nutrients

Correct answer: B

Rationale: The large intestine's primary function is to absorb water from the remaining indigestible food matter that enters it from the small intestine. This absorption process helps in forming solid waste (feces) by compacting the material and preparing it for excretion. The large intestine does not secrete digestive enzymes, produce bile, or transport nutrients. Therefore, option B, 'To absorb water and form solid waste,' is the correct function of the large intestine in the digestive system.

5. What is the function of the gallbladder?

A. To produce bile
B. To store and concentrate bile
C. To detoxify harmful substances
D. To break down fats

Correct answer: B

Rationale: The correct answer is B: To store and concentrate bile. The gallbladder's primary function is to store and concentrate bile, which is produced by the liver. Bile is released into the small intestine to aid in the digestion and absorption of fats. It helps in emulsifying fats and facilitating their breakdown by enzymes for better absorption. Choices A, C, and D are incorrect because the gallbladder does not produce bile (it is produced by the liver), detoxify harmful substances, or directly break down fats. Its main role is to store and concentrate bile before releasing it into the small intestine.