Which structure in the brain is involved in regulating body temperature?

Correct Answer: B

Rationale: The correct answer is B, the Hypothalamus. The hypothalamus plays a crucial role in regulating body temperature, hunger, thirst, and other autonomic functions, aiding in the maintenance of homeostasis within the body. It acts as the body's thermostat, responding to internal and external temperature changes to keep the body within a narrow temperature range. Choices A, C, and D are incorrect. The cerebellum is mainly involved in coordinating voluntary movements and balance. The medulla oblongata controls vital functions such as heartbeat and breathing. The pineal gland is responsible for producing melatonin, which regulates sleep-wake cycles.

Correct Answer: C

Rationale: The amygdala, located in the temporal lobe of the brain, is responsible for regulating emotions and memory, particularly those related to fear and pleasure. It plays a crucial role in processing emotional responses, forming emotional memories, and modulating emotional reactions. The cerebrum (Choice A) is responsible for higher brain functions such as thought and action. The cerebellum (Choice B) is mainly involved in coordination and balance. The brainstem (Choice D) controls basic life functions such as breathing and heart rate.

Correct Answer: A

Rationale: The main function of the digestive system is to break down food into nutrients through the process of digestion. Once the food is broken down, the nutrients are absorbed into the bloodstream and utilized by the body for various functions. Choice B, regulating body temperature, is incorrect as it is the function of the body's thermoregulatory system, not the digestive system. Choice C, transporting nutrients, is incorrect as the digestive system primarily focuses on breaking down and absorbing nutrients rather than transporting them. Choice D, producing hormones, is also incorrect as hormone production is mainly carried out by endocrine glands and not the digestive system.

Correct Answer: B

Rationale: The correct answer is B: Pivot joint. A pivot joint, like the one found in the neck, allows for rotational movement, enabling the head to turn from side to side. Hinge joints (Choice A) allow movement in one plane like a door hinge and are not found in the neck. Ball and socket joints (Choice C) allow for a wide range of motion in multiple directions and are typically found in the hip and shoulder. Saddle joints (Choice D) allow for movement back and forth and side to side, like the thumb joint, but are not found in the neck.

Correct Answer: C

Rationale: Mitochondria are commonly referred to as the powerhouses of the cell as they are primarily responsible for generating energy through cellular respiration. This process involves converting nutrients into adenosine triphosphate (ATP), which is the main energy currency of the cell. The nucleus is responsible for storing the cell's genetic material, the ribosome is involved in protein synthesis, and the Golgi apparatus is responsible for packaging and distributing molecules produced by the cell; therefore, they are not directly involved in energy generation.