which part of the eye is responsible for color vision

HESI A2

HESI A2 Anatomy and Physiology 2023

1. Which part of the eye is responsible for color vision?

A. Cornea
B. Iris
C. Retina
D. Lens

Correct answer: C

Rationale: The correct answer is option C: Retina. The retina contains photoreceptor cells, including cones that are responsible for color vision. Cones are sensitive to different wavelengths of light, allowing us to perceive and differentiate various colors. Choice A, Cornea, is the transparent outer layer of the eye that helps focus light. It does not play a direct role in color vision. Choice B, Iris, is the colored part of the eye that controls the size of the pupil and regulates the amount of light entering the eye. While it is essential for adjusting light levels, it is not directly involved in color vision. Choice D, Lens, is responsible for focusing light onto the retina. It helps to form clear images on the retina but does not play a role in color vision.

2. Which of the heart's four chambers is the largest and the strongest?

A. Right atrium
B. Left ventricle
C. Right ventricle
D. Left atrium

Correct answer: B

Rationale: The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the body, making it vital for systemic circulation. The right atrium receives deoxygenated blood from the body, the right ventricle pumps this blood to the lungs, and the left atrium receives oxygenated blood from the lungs.

3. What is the function of the pancreas in digestion?

A. Secreting digestive enzymes
B. Producing bile
C. Storing glucose
D. Regulating blood sugar levels

Correct answer: A

Rationale: The correct answer is A: Secreting digestive enzymes. The pancreas aids in digestion by secreting digestive enzymes that are essential for breaking down carbohydrates, fats, and proteins in the small intestine. These enzymes help in the absorption of nutrients from food, facilitating the digestive process. Choices B, C, and D are incorrect. The pancreas does not produce bile (choice B), store glucose (choice C), or primarily regulate blood sugar levels (choice D) in the context of digestion.

4. What is the main function of the urinary bladder?

A. To filter blood
B. To store and concentrate bile
C. To store urine
D. To absorb nutrients

Correct answer: C

Rationale: The correct answer is C: To store urine. The main function of the urinary bladder is to store urine produced by the kidneys before it is excreted from the body. It acts as a reservoir for urine until it is expelled during urination. Choices A, B, and D are incorrect because the urinary bladder does not filter blood, store or concentrate bile, or absorb nutrients. It is solely responsible for storing and releasing urine.

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

A. To remove carbon dioxide from the body
B. To transport oxygen to the cells
C. To deliver nutrients to cells
D. To create sound and speech

Correct answer: B

Rationale: The primary function of the respiratory system is to facilitate the exchange of gases. It transports oxygen from the air into the bloodstream, which is crucial for cellular respiration and providing energy to the cells. Additionally, it removes carbon dioxide, which is a waste product that needs to be eliminated. Choices A, C, and D are incorrect because while the respiratory system does remove carbon dioxide, its primary role is oxygen transport, not nutrient delivery, sound, or speech production.