peripheral vasodilation results in heat loss through which of the following processes

ATI RN

ATI Anatomy and Physiology

1. Peripheral vasodilation results in heat loss through which of the following processes?

A. conduction
B. convection
C. radiation
D. evaporation

Correct answer: C

Rationale: Peripheral vasodilation is the widening of blood vessels near the surface of the skin, allowing more blood to flow near the skin's surface. This process enhances heat loss primarily through radiation. Radiation is the transfer of heat energy in the form of electromagnetic waves. Conduction involves direct contact between objects, convection involves the transfer of heat through fluid or gas, and evaporation involves the phase change of a liquid to a gas, which cools the surface.

2. Positive feedback mechanisms usually result in

A. changes returning values away from a set point.
B. stable conditions around a set point.
C. unstable conditions.
D. long-term changes.

Correct answer: C

Rationale: Positive feedback mechanisms usually result in unstable conditions. In a positive feedback loop, the output enhances or amplifies the changes that are occurring, leading to a deviation from the initial set point. Therefore, positive feedback does not bring values back towards the set point (Choice A). Choice B is incorrect because positive feedback does not promote stability around a set point. Choice D is also incorrect as positive feedback mechanisms typically do not lead to long-term changes; instead, they intensify the initial change, causing instability.

3. A parietal layer of a serous membrane lines cavities, whereas a visceral layer of a serous membrane covers organs.

A. covers organs; lines cavities
B. lines cavities; covers organs
C. secretes serous fluid; secretes mucus
D. secretes mucus; secretes a serous fluid

Correct answer: B

Rationale: In serous membranes, the parietal layer lines the cavities, providing support and protection, while the visceral layer covers the organs, reducing friction and allowing them to move freely. Therefore, the correct answer is 'lines cavities; covers organs.' Choices C and D are incorrect because serous membranes do not secrete mucus; instead, they secrete a watery serous fluid. Choice A is incorrect as it reverses the functions of the parietal and visceral layers in relation to organs and cavities.

4. Which part of the nephron is closest to the collecting duct?

A. Distal convoluted tubule (DCT)
B. Bowman's Capsule
C. Afferent Arteriole
D. Proximal Convoluted Tubule (PCT)

Correct answer: A

Rationale: The correct answer is the Distal convoluted tubule (DCT). The DCT is the part of the nephron closest to the collecting duct, where the final adjustments to electrolyte and fluid balance are made. Bowman's Capsule is located at the beginning of the nephron, where filtration of blood occurs. The Afferent Arteriole brings blood to the glomerulus for filtration. The Proximal Convoluted Tubule (PCT) is situated after the Bowman's Capsule and is not the part closest to the collecting duct.

5. Are kidneys part of the lymphatic system?

A. TRUE
B. FALSE
C. Not Sure
D. None of the above

Correct answer: B

Rationale: The correct answer is False. Kidneys are not part of the lymphatic system; they are part of the urinary system. The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. Therefore, choices A, C, and D are incorrect because kidneys are not associated with the lymphatic system.