ATI TEAS Science Questions

Correct Answer: D

Rationale: The correct answer is D, Myocardium. The myocardium is the cardiac muscle layer that comprises the majority of the heart's muscle mass. It is responsible for the heart's contractions, allowing it to pump blood throughout the body. The endocardium is the innermost layer of the heart lining the chambers, while the epicardium is the outermost layer covering the heart. The fibrous skeleton provides structural support and serves as an attachment point for cardiac muscle fibers. Therefore, choices A, B, and C are incorrect as they do not represent the primary muscle layer of the heart.

Correct Answer: C

Rationale: The correct answer is C: Immune cells. Immune cells, such as macrophages, contain many lysosomes for breaking down pathogens. Lysosomes are organelles responsible for digestion and waste removal within the cell, and immune cells require a high concentration of lysosomes to aid in their defense mechanisms against pathogens. Choice A, Cardiac cells, is incorrect because lysosomes are not primarily abundant in cardiac cells. Choice B, Glandular cells, is incorrect as well since lysosomes are not specifically concentrated in glandular cells. Choice D, Neurons, is also incorrect because while lysosomes are present in neurons, they are not typically found in high concentrations compared to immune cells.

Correct Answer: C

Rationale: Blood pressure is controlled by baroreceptors located in the aortic arch and carotid arteries that detect changes in blood pressure levels. When blood pressure is high, these receptors signal for adjustments to lower it. Additionally, hormones such as renin from the kidneys are released when blood pressure drops, further aiding in blood pressure regulation. Choice A is incorrect because blood pressure regulation involves more than just adjusting heart rate; it also includes vasodilation and vasoconstriction. Choice B is incorrect as while blood volume can impact blood pressure, it is not the primary mechanism of blood pressure control. Choice D is incorrect as body temperature regulation is a separate physiological process and not directly related to blood pressure control.

Correct Answer: B

Rationale: Silicon has an atomic number of 14, indicating it has 14 protons. The atomic mass of 28.1 AMU accounts for both protons and neutrons in the nucleus. By subtracting the atomic number from the atomic mass, we can estimate the number of neutrons in the atom. Thus, 28.1 - 14 = 14 neutrons. Choice A is incorrect as it represents the total atomic mass, not the number of neutrons. Choice C is incorrect; it is the atomic number (protons) rather than the number of neutrons. Choice D is incorrect as it is a value that does not reflect the number of neutrons in the silicon atom.

Correct Answer: C

Rationale: The correct answer is C, continuous capillaries. Continuous capillaries are the most common and least permeable type of capillary. They are found in most tissues, including muscle and the nervous system. Continuous capillaries have a continuous endothelium without fenestrations or large gaps, which limits the movement of substances across their walls. Choice A, fenestrated capillaries, have pores (fenestrations) in their endothelial cells, making them more permeable than continuous capillaries. Choice B, sinusoidal capillaries, have a discontinuous endothelium with large gaps between cells, making them more permeable and allowing larger molecules and cells to pass through compared to continuous capillaries. Choice D, discontinuous capillaries, are similar to sinusoidal capillaries with a discontinuous endothelium, allowing for enhanced permeability compared to continuous capillaries.