ATI TEAS Practice Science Test

Correct Answer: C

Rationale: The correct order is C: Thrombocytes, erythrocytes, and leukocytes. Thrombocytes (platelets) are the smallest, followed by erythrocytes (red blood cells), then leukocytes (white blood cells). This order is based on the size of these blood cell types, with thrombocytes being the smallest and leukocytes being the largest. Thrombocytes play a crucial role in blood clotting, erythrocytes are responsible for oxygen transport, and leukocytes are essential for immune function. Incorrect choices: A: Incorrect order; leukocytes are the largest, not the smallest. B: Incorrect order; thrombocytes are the smallest, not the largest. D: Incorrect order; leukocytes are larger than erythrocytes, so the order is incorrect.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver plays a crucial role in storing and metabolizing vitamins, releasing them as needed when intake decreases. It helps maintain vitamin levels in the body. The other choices are incorrect because the appendix has no role in vitamin absorption or regulation, the pancreas primarily aids in digestion and hormone regulation, and the stomach's main function is to break down food, not regulate vitamin levels.

Correct Answer: C

Rationale: The correct answer is C: Hypothalamus. The hypothalamus is a major structure of the limbic system responsible for regulating various essential functions like emotions, behavior, and physiological processes. It plays a crucial role in the control of thirst, hunger, body temperature, and hormonal regulation. The brainstem (A) is involved in basic life functions like breathing and heart rate, but it is not a part of the limbic system. The spinal cord (B) primarily functions in transmitting sensory and motor signals but is not directly related to the limbic system. The cerebral cortex (D) is responsible for higher-order thinking, sensory processing, and motor functions but is not a major structure of the limbic system.

Correct Answer: C

Rationale: The correct answer is C: Shaft. The shaft is the portion of the hair that is visible above the skin's surface and is not attached to the follicle. The bulb (A) is the base of the hair follicle where the hair root (B) is located and is attached to the follicle. The strand (D) refers to the entire hair structure, including the bulb, root, and shaft. Therefore, the shaft is the only part that is not physically connected to the follicle.

Correct Answer: A

Rationale: The correct answer is A because the pharynx serves as a common passageway for both food and air. It allows food to pass from the mouth to the esophagus and air to pass from the nasal cavity to the larynx. It plays a crucial role in the process of swallowing and breathing. Choice B is incorrect because the warming and moistening of air during inhalation primarily occur in the nasal cavity and the respiratory tract, not the pharynx. Choice C is incorrect as the creation of a chest cavity at the base of the lungs is primarily the function of the diaphragm, not the pharynx. Choice D is incorrect as the structural support to the alveolar region is mainly provided by the alveoli themselves and surrounding tissues, not the pharynx.