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 vitamin is essential for the formation of red blood cells?

A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin D

Correct answer: B

Rationale: Vitamin B12 is the correct answer. It is crucial for the formation and maturation of red blood cells, playing a vital role in preventing megaloblastic anemia. Additionally, Vitamin B12 is essential for maintaining nerve function. Vitamin A is important for vision and immune function, Vitamin C is necessary for collagen synthesis and immune health, and Vitamin D is crucial for bone health and immune function. Therefore, options A, C, and D are incorrect as they do not play a direct role in the formation of red blood cells.

3. What is the primary function of the skin in the integumentary system?

A. Regulating body temperature
B. Protecting the body from external damage
C. Producing red blood cells
D. Producing hormones

Correct answer: B

Rationale: The primary function of the skin in the integumentary system is to protect the body from external damage. The skin acts as a barrier against pathogens, UV radiation, and physical trauma. While the skin does help regulate body temperature by sweating and vasodilation, its main role is protection. Skin does not produce red blood cells; this is the function of the bone marrow. Hormones are primarily produced by endocrine glands, not the skin.

4. Which plane would you use to separate the abdominal cavity from the thoracic cavity?

A. Sagittal
B. Transverse
C. Frontal
D. Coronal

Correct answer: B

Rationale: The transverse plane, also known as the horizontal plane, runs horizontally from left to right, dividing the body into superior (upper) and inferior (lower) parts. This plane is ideal for separating the abdominal cavity (located below) from the thoracic cavity (located above). The sagittal plane (choice A) divides the body into left and right portions, the frontal plane (choice C) divides the body into front and back portions, and the coronal plane (choice D) is another term for the frontal plane. Therefore, when looking to separate the abdominal cavity from the thoracic cavity, the transverse plane is the most appropriate choice.

5. Which vitamin is necessary for blood clotting?

A. Vitamin D
B. Vitamin K
C. Vitamin C
D. Vitamin B12

Correct answer: B

Rationale: Vitamin K is essential for the synthesis of proteins involved in blood clotting. These proteins help in the coagulation process, ensuring that wounds can heal properly by preventing excessive bleeding. Without sufficient Vitamin K, the blood clotting process may be impaired, leading to potential health risks. Vitamin D is important for bone health, Vitamin C is essential for the immune system and collagen production, and Vitamin B12 plays a role in red blood cell production and nerve function, but they are not directly involved in the blood clotting process.