Study of mammary glands are called

Correct Answer: A

Rationale: The correct answer is A: Mastology. The term "masto-" refers to breasts or mammary glands, making mastology the study of mammary glands. Stomatology (B) is the study of the mouth and its diseases, heptatology (C) is the study of the liver, and angiology (D) is the study of blood vessels. Therefore, A is the only choice that accurately represents the study of mammary glands.

Correct Answer: B

Rationale: The correct answer is B: Dermis. Leather is obtained from the dermis layer of animal skin, where the collagen fibers are tightly packed, providing strength and durability. The dermis contains the necessary components for tanning and processing into leather. Epidermis (A) is the outermost layer of the skin and does not contain the required collagen fibers. Adipose tissues (C) are responsible for fat storage and do not contribute to leather production. Collagen fibers (D) are present in the dermis, but the process of converting them into leather involves the entire dermal layer, not just the fibers alone.

Correct Answer: C

Rationale: The correct answer is C: Involuntary. Arrector pili muscles are small muscles attached to hair follicles that contract involuntarily in response to various stimuli like cold or fear. They cause hairs to stand on end, known as "goosebumps." Choice A is incorrect because arrector pili muscles are not under voluntary control. Choice B is incorrect because they are purely involuntary. Choice D is incorrect as the correct answer is C.

Correct Answer: C

Rationale: The correct answer is C: Less sweat in cold weather. During cold weather, the body's sweat glands produce less sweat as a way to conserve heat. This decrease in sweat production leads to less moisture on the skin, causing it to become dry. Vasodilation (choice A) is the widening of blood vessels, which can actually lead to increased moisture on the skin. Vasoconstriction (choice B) is the narrowing of blood vessels, which can affect blood flow but not directly contribute to dry skin. Choice D is incorrect as less sweat production in cold weather is the primary reason for dry skin.

Correct Answer: C

Rationale: The correct answer is C: Nerves. Nails do not contain nerves, which are responsible for transmitting pain signals to the brain. Without nerves, the sensation of pain cannot be felt when cutting the nails. Blood vessels (choice A) and bones (choice B) are not directly related to the sensation of pain in this scenario. Choice D is incorrect as nails do not contain any of these structures that would transmit pain. In summary, the absence of nerves in nails is the reason why we do not feel pain when cutting them.