ATI TEAS Science Questions

Correct Answer: C

Rationale: Option C, 'It helps cushion the heart against jarring motions,' is NOT a major function of the respiratory system in humans. The primary functions of the respiratory system include gas exchange, regulation of blood pH, and vocalization. The respiratory system does not play a role in cushioning the heart; that function is primarily carried out by the pericardium and other protective structures around the heart. Choices A, B, and D are major functions of the respiratory system in humans. Choice A refers to the respiratory system's role in gas exchange, Choice B highlights its involvement in regulating blood pH, and Choice D points out its responsibility for vocalization.

Correct Answer: A

Rationale: The correct answer is A: Complement system. The complement system is a vital component of the immune system responsible for destroying pathogens through various mechanisms like promoting inflammation, enhancing phagocytosis, and directly lysing pathogens. Fibrinogen is crucial for blood clotting, the major histocompatibility complex is involved in immune responses, and platelets aid in blood clotting and wound healing. However, none of these directly destroy pathogens as the complement system does.

Correct Answer: B

Rationale: Correct. Positive feedback loops enhance or amplify changes, which can sometimes be harmful as they drive processes further from equilibrium. In contrast, negative feedback loops work to counteract deviations from a set point, promoting stability. Choice A, 'Negative feedback loop,' is incorrect because negative feedback loops inhibit or reduce changes, promoting stability. Choice C, 'Inhibitory feedback loop,' is incorrect as it is synonymous with negative feedback loops. Choice D, 'Stimulating feedback loop,' is incorrect as it inaccurately describes the nature of positive feedback loops.

Correct Answer: C

Rationale: The correct answer is C: Duodenum, jejunum, ileum. The small intestine is divided into three regions: the duodenum, jejunum, and ileum. The duodenum is the initial segment where most chemical digestion takes place. The jejunum and ileum follow the duodenum and are primarily responsible for nutrient absorption. Choice A is incorrect because the order is incorrect. Choice B is incorrect because the cecum is part of the large intestine, not the small intestine. Choice D is incorrect because the colon is part of the large intestine, not the small intestine.

Correct Answer: A

Rationale: The trachea is the structure that bifurcates into the primary bronchi. The trachea is a tube that carries air to and from the lungs. It divides into the left and right primary bronchi at a specific point called the carina, which then further divide into secondary and tertiary bronchi, leading to the bronchioles. The alveoli are the tiny air sacs at the end of the bronchioles where gas exchange occurs, not the structure that bifurcates into the primary bronchi. Bronchioles are smaller airway branches that come after the bronchi but do not bifurcate into them. The larynx, also known as the voice box, is located above the trachea and is responsible for sound production, not the bifurcation into primary bronchi. Therefore, the correct answer is the trachea.