ATI TEAS Science Practice Test

Correct Answer: B

Rationale: Smooth muscle is the only involuntary, non-striated muscle type in the body. It is found in organs like the intestines and blood vessels, where it controls movements without conscious effort. Choice A is incorrect because voluntary muscles are under conscious control, while smooth muscle is involuntary. Choice C is incorrect because striations are not present in smooth muscle, unlike skeletal muscle. Choice D is incorrect because smooth muscle is not voluntary and lacks striations, making it different from skeletal muscle.

Correct Answer: A

Rationale: The correct answer is A: Negative feedback loop. Negative feedback loops work to inhibit the stimulus or reduce the deviation from a set point, maintaining homeostasis by counteracting any changes from the norm. In this case, the negative feedback loop acts to minimize any deviation from the body's internal balance, ensuring stability and optimal functioning. Choice B, a positive feedback loop, amplifies the stimulus or deviation, moving systems away from homeostasis. Choice C, an inhibitory feedback loop, is not a commonly recognized term in the context of feedback mechanisms. Choice D, a stimulating feedback loop, is not a standard term and does not accurately describe a feedback loop's role in maintaining homeostasis.

Correct Answer: B

Rationale: The correct answer is B: Skeletal, cardiac, smooth. Skeletal muscle tissue is responsible for voluntary movement, cardiac muscle tissue is found in the heart and is responsible for involuntary heart contractions, and smooth muscle tissue is located in organs and is responsible for involuntary movements. Therefore, the three types of muscle tissues are skeletal, cardiac, and smooth. Choices A, C, and D are incorrect because they include types of tissues that are not classified as muscle tissues. Epithelial and connective tissues are different types of tissues that serve other functions in the body, not related to muscle contractions.

Correct Answer: C

Rationale: Eosinophils are best described as a type of granulocyte found under mucous membranes that defends against multicellular parasites. They release toxic substances to combat parasitic infections and play a significant role in allergic reactions and asthma. Histamine secretion to stimulate inflammation is more characteristic of basophils, while high phagocytic activity and aggressiveness are features of neutrophils, not eosinophils. Describing eosinophils as the most abundant type of white blood cell that secretes toxic substances to pathogens is inaccurate since eosinophils specifically target multicellular parasites, not a broad range of pathogens.

Correct Answer: C

Rationale: The correct answer is C: Connective tissue. The dermis is primarily composed of connective tissue, which includes collagen and elastin fibers that provide strength and elasticity to the skin. It houses blood vessels, nerve endings, hair follicles, and glands, playing a crucial role in supporting the skin structure and function. Adipose tissue (choice A) is found in the subcutaneous layer beneath the dermis, providing insulation and energy storage. Epithelial cells (choice B) form the outermost layer of the skin called the epidermis. Muscle tissue (choice D) is not a significant component of the dermis but is found deeper in the body associated with movement and support.