which valve prevents the return of blood into the right ventricle

ATI TEAS 7

ATI TEAS Science Questions

1. Which valve prevents the return of blood into the right ventricle?

A. Pulmonary semilunar valve
B. Aortic semilunar valve
C. Tricuspid valve
D. Mitral valve

Correct answer: A

Rationale: The correct answer is A: Pulmonary semilunar valve. The pulmonary semilunar valve is located between the right ventricle and the pulmonary artery. It opens to allow blood to be pumped into the pulmonary artery but closes to prevent blood from returning back into the right ventricle. The aortic semilunar valve is located between the left ventricle and the aorta. The tricuspid valve is located between the right atrium and right ventricle, and the mitral valve is located between the left atrium and left ventricle. Therefore, the pulmonary semilunar valve is the specific valve responsible for preventing the backflow of blood into the right ventricle during the cardiac cycle.

2. Which of the following glands produces growth hormone?

A. Pituitary
B. Thyroid
C. Adrenal
D. Pancreas

Correct answer: A

Rationale: The correct answer is A: Pituitary. The pituitary gland, also known as the master gland, produces growth hormone, which plays a crucial role in stimulating growth and cell reproduction. Choice B, the thyroid gland, primarily produces hormones that regulate metabolism, not growth hormone. Choice C, the adrenal glands, produce hormones like cortisol and adrenaline, but not growth hormone. Choice D, the pancreas, produces insulin and glucagon for regulating blood sugar levels, not growth hormone.

3. Which muscles play a significant role in the process of forced exhalation by contracting to reduce the thoracic cavity volume?

A. Diaphragm
B. External intercostal muscles
C. Internal intercostal muscles
D. Abdominal muscles

Correct answer: D

Rationale: The abdominal muscles play a significant role in forced exhalation by contracting to reduce the thoracic cavity volume. When these muscles contract, the pressure within the thoracic cavity increases, assisting in the expulsion of air from the lungs. This action helps to compress the abdomen and push the diaphragm upwards, further decreasing the volume of the thoracic cavity and aiding in the exhalation process. The diaphragm (Choice A) is mainly involved in inhalation by contracting and moving downward to increase thoracic cavity volume. External intercostal muscles (Choice B) and internal intercostal muscles (Choice C) are primarily involved in the process of inhalation by expanding the thoracic cavity during normal breathing, rather than forced exhalation.

4. If a scientist finds that the results of her experiment seem to contradict her hypothesis, what is the best course of action?

A. Publish the results anyway, acknowledging that her hypothesis seems to have been incorrect.
B. Keep trying the experiment until the results match her hypothesis.
C. Publish the results, retroactively changing the hypothesis.
D. None of the above; this cannot occur. The experimental results cannot contradict the hypothesis, by definition.

Correct answer: A

Rationale: The best course of action is to publish the results anyway, acknowledging that her hypothesis seems to have been incorrect. Science relies on accurate reporting and transparency, even if the results do not align with the original hypothesis. This allows for further discussion, analysis, and potentially new hypotheses to be developed based on the findings. It is essential in scientific research to report both positive and negative results to contribute to the body of knowledge and advance understanding in the field. Choice B is incorrect because persisting with the same experiment to force results to align with the hypothesis goes against scientific integrity and may lead to biased conclusions. Choice C is incorrect as changing the hypothesis after obtaining results is not scientifically sound and undermines the credibility of the research. Choice D is incorrect because science embraces the possibility of experimental results contradicting hypotheses, as this provides valuable insights for refining theories and expanding scientific knowledge.

5. Which of the following statements is true regarding the ventricles of the heart?

A. The left ventricle pumps blood into the aorta
B. The right ventricle pumps blood into the pulmonary trunk
C. Ventricles are the discharging chambers of the heart
D. All of the above

Correct answer: D

Rationale: All of these statements are true regarding the ventricles of the heart. The left ventricle does indeed pump oxygenated blood into the aorta, while the right ventricle pumps deoxygenated blood into the pulmonary trunk. Ventricles are indeed the discharging chambers of the heart, responsible for pumping blood out into the circulatory system. Therefore, as all the statements are accurate, the correct answer is 'All of the above.' Choices A, B, and C are all correct statements about the ventricles, making them incorrect answers in isolation.