Anatomy HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Occipital lobe. The occipital lobe is primarily responsible for processing visual information. It contains the primary visual cortex, which receives and interprets visual stimuli from the eyes. This region processes shapes, colors, and motion. The temporal lobe (A) is involved in memory and auditory processing. The parietal lobe (C) is responsible for spatial awareness and sensory information integration. The frontal lobe (D) is associated with executive functions and motor skills. Thus, the occipital lobe is the correct choice for processing visual information.

Correct Answer: A

Rationale: The correct answer is A: They secrete chemicals into the blood. Endocrine glands are ductless glands that secrete hormones directly into the bloodstream. This allows the hormones to travel throughout the body to target organs and tissues. Choices B, C, and D are incorrect because endocrine glands do not secrete enzymes into ducts (B), produce sweat (C), or produce saliva (D). These functions are typically associated with exocrine glands that have ducts for secretion.

Correct Answer: C

Rationale: Platelets play a crucial role in blood clotting, known as hemostasis. Step 1: When a blood vessel is damaged, platelets adhere to the site to form a temporary plug. Step 2: Platelets release chemicals that attract more platelets and help in clot formation. Step 3: This clotting process prevents excessive bleeding. Choice A is incorrect as oxygen is primarily carried by red blood cells. Choice B is incorrect as fighting infections is mainly done by white blood cells. Choice D is incorrect as nutrient transport is mainly carried out by the plasma in the blood.

Correct Answer: C

Rationale: The primary function of hemoglobin in red blood cells is to carry oxygen. Hemoglobin binds to oxygen in the lungs and releases it to tissues throughout the body. This process is essential for cellular respiration. Choice A is incorrect because hemoglobin does not transport nutrients. Choice B is incorrect because the function of fighting infections is carried out by the immune system, not hemoglobin. Choice D is incorrect because hemoglobin does not produce energy; it facilitates the transport of oxygen which is necessary for energy production in cells.

Correct Answer: B

Rationale: The correct answer is B: Lens. The lens of the eye is responsible for focusing light onto the retina by changing its shape to adjust the focal length. The cornea (A) helps in the initial focusing of light but does not have the ability to adjust focus. The retina (C) is the layer of cells at the back of the eye where light is converted into electrical signals, not responsible for focusing light. The pupil (D) controls the amount of light entering the eye but does not focus light onto the retina.