ati teas 7 science

Correct Answer: C

Rationale: The correct answer is C: Buffering system. The body maintains a relatively constant blood pH level through the buffering system, which involves the action of bicarbonate ions, carbonic acid, and other buffering molecules that help regulate pH by neutralizing excess acids or bases. This system acts quickly to prevent drastic changes in blood pH when there are fluctuations in blood carbon dioxide concentration. Cellular respiration (A) generates carbon dioxide, gas exchange (B) involves the exchange of gases in the lungs, and deoxygenation (D) refers to the loss of oxygen by the blood, but these processes are not primarily responsible for maintaining blood pH stability.

Correct Answer: D

Rationale: The correct answer is D: Aorta. The aorta is responsible for pumping oxygenated blood to the body. This happens after the oxygenated blood leaves the left ventricle of the heart through the aortic valve. The aorta is the largest artery in the body and carries blood to all parts of the body, supplying oxygen and nutrients. The other choices are incorrect because: A: Right ventricle pumps deoxygenated blood to the lungs. B: Left ventricle pumps oxygenated blood to the body. C: Pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation.

Correct Answer: A

Rationale: The primary function of the coronary arteries is to carry oxygenated blood to the heart muscle. This is essential for providing the heart muscle with the oxygen and nutrients it needs to function properly. Without adequate oxygen supply, the heart muscle can become damaged, leading to conditions like heart attacks. The other choices are incorrect because: B: Coronary arteries do not carry deoxygenated blood from the heart muscle; they supply oxygenated blood to it. C: Pumping blood to the lungs for oxygenation is the function of the pulmonary arteries, not the coronary arteries. D: Regulating blood pressure in the systemic circulation is primarily the function of the arteries and arterioles throughout the body, not specifically the coronary arteries.

Correct Answer: A

Rationale: The primary function of the digestive system is to break down food into nutrients for absorption by the body. This process involves mechanical and chemical digestion to convert food into molecules that can be absorbed by the intestines. Option A is correct as it describes this essential function. Option B is incorrect because the absorption of oxygen primarily occurs in the respiratory system. Option C is incorrect as the production of energy is mainly attributed to the metabolic processes within cells. Option D is incorrect as the regulation of body temperature is primarily controlled by the thermoregulatory system, not the digestive system.

Correct Answer: B

Rationale: The correct answer is B: Pivot joint. Pivot joints allow rotational movement around a single axis, such as the rotation of the radius around the ulna in the forearm. This type of joint is designed to facilitate the turning or twisting motion. Ball-and-socket joints (A) allow for multi-axial movement, hinge joints (C) enable movement in one direction like a door hinge, and saddle joints (D) have two saddle-shaped surfaces that allow for movement in multiple directions, but not specifically rotational movement around a single axis.