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 are muscle contractions that normally move food along the human digestive system known as?

A. defecation
B. osmosis
C. peristalsis
D. circulation

Correct answer: C

Rationale: Muscle contractions that move food along the human digestive system are known as peristalsis. Peristalsis consists of a series of coordinated muscular contractions and relaxations that help propel food through the esophagus, stomach, and intestines, facilitating efficient digestion and nutrient absorption. Defecation refers to expelling waste from the body, osmosis is the movement of water across a membrane, and circulation relates to the movement of blood in the body's circulatory system, not directly involved in food transportation along the digestive tract.

3. Which type of blood cell is responsible for carrying oxygen?

A. Red blood cells
B. White blood cells
C. Platelets
D. Plasma cells

Correct answer: A

Rationale: The correct answer is A: Red blood cells. Red blood cells, also known as erythrocytes, are specialized cells designed to transport oxygen from the lungs to tissues and organs throughout the body. These cells contain hemoglobin, a protein that binds to oxygen molecules in the lungs and releases them in other parts of the body where oxygen is needed for cellular respiration. White blood cells (choice B) are part of the immune system, responsible for fighting infections. Platelets (choice C) are involved in blood clotting. Plasma cells (choice D) are a type of white blood cell that produces antibodies to help the body fight off infections.

4. How does the endocrine system work with the reproductive system?

A. The reproductive system transforms minerals into useful nutrients.
B. The endocrine system determines the sex of the embryo.
C. The reproductive system controls the growth of secondary sex organs.
D. The endocrine system produces chemicals that regulate sexual function.

Correct answer: D

Rationale: The correct answer is D. The endocrine system plays a vital role in the regulation of sexual functions within the reproductive system. It produces hormones that are responsible for various functions, such as the development of secondary sex characteristics, production of gametes (sperm and egg cells), and the regulation of the menstrual cycle. These hormones are crucial for the proper functioning and coordination of the reproductive system, ensuring the successful reproduction and maintenance of reproductive health. Choices A, B, and C are incorrect because the reproductive system is not primarily responsible for transforming minerals into nutrients, determining the sex of the embryo, or controlling the growth of secondary sex organs. These functions are mainly regulated by the endocrine system in coordination with the reproductive system.

5. Which hormone regulates blood sugar levels?

A. Insulin
B. Glucagon
C. Cortisol
D. Thyroxine

Correct answer: A

Rationale: Insulin is the hormone that regulates blood sugar levels by promoting the uptake of glucose into cells. It is produced by the pancreas and helps to lower blood sugar levels when they are too high. Glucagon, on the other hand, works in opposition to insulin by raising blood sugar levels when they are too low. Cortisol and thyroxine play different roles in the body and are not primarily responsible for regulating blood sugar levels.