Anatomy HESI A2 Practice Test

Correct Answer: A

Rationale: The correct answer is A: To filter blood and remove old red blood cells. The spleen is an important organ in the lymphatic system responsible for filtering blood, removing old or damaged red blood cells, and storing platelets. It also plays a role in immune function by producing antibodies and storing lymphocytes. Choices B, C, and D are incorrect as the spleen's main functions are related to blood filtration and immune response, not lymphocyte production, vitamin storage, or temperature regulation.

Correct Answer: B

Rationale: The correct answer is B: Larynx. The larynx is an organ of the respiratory system responsible for producing sound and protecting the trachea during swallowing. It is located in the throat region and contains vocal cords. The brain (A) is part of the nervous system, not the respiratory system. The urethra (C) is part of the urinary system, and the pancreas (D) is part of the digestive system. Therefore, the larynx is the only choice directly related to the respiratory system.

Correct Answer: C

Rationale: Platelets' primary function is to clot blood. When a blood vessel is damaged, platelets rush to the site and form a plug to stop bleeding. Platelets release chemicals that promote clotting. Platelets do not carry oxygen (A), fight infections (B), or transport nutrients (D). Oxygen is carried by red blood cells, immunity is the function of white blood cells, and nutrients are transported by plasma.

Correct Answer: B

Rationale: White blood cells' main function is to fight infections. They are part of the immune system, detecting and destroying pathogens like bacteria and viruses. They do not carry oxygen (A), nutrients (C), or remove waste products (D). White blood cells play a crucial role in protecting the body from harmful invaders, making choice B the correct answer.

Correct Answer: B

Rationale: The correct answer is B: To store and concentrate bile. The gallbladder acts as a reservoir for bile produced by the liver, which is then released into the small intestine to aid in digestion. Bile helps emulsify fats for better absorption. Choices A, C, and D are incorrect as the gallbladder does not produce bile (the liver does), detoxify harmful substances, or directly break down fats. The primary function of the gallbladder is to store and concentrate bile for efficient digestion.