Which hormone is produced by the pancreas to lower blood glucose levels?

Correct Answer: B

Rationale: The correct answer is B: Insulin. Insulin, produced by the pancreas, is the hormone responsible for lowering blood glucose levels. It achieves this by promoting the uptake of glucose into cells, thereby reducing the concentration of glucose in the bloodstream. Choice A, Glucagon, is actually a hormone produced by the pancreas that works to raise blood glucose levels by stimulating the liver to release stored glucose. Choice C, Cortisol, is a hormone produced by the adrenal glands, not the pancreas, and is involved in stress response and regulation of metabolism. Choice D, Melatonin, is a hormone produced by the pineal gland that regulates sleep-wake cycles and is not directly involved in blood glucose level regulation.

Correct Answer: B

Rationale: The urethra is the correct answer because it is a tube that is part of both the male reproductive system and the urinary system. It allows urine to pass out of the body as part of the urinary system and also transports semen as part of the male reproductive system. The bladder (Choice A) is solely part of the urinary system, storing urine. The prostate (Choice C) is part of the male reproductive system, secreting fluids that nourish and protect sperm. The seminal vesicle (Choice D) is also part of the male reproductive system, producing seminal fluid that mixes with sperm to form semen.

Correct Answer: C

Rationale: The appendix is involved in the immune system as it is believed to play a role in maintaining and protecting beneficial gut bacteria, especially after gastrointestinal illnesses. This helps in restoring the balance of intestinal bacteria crucial for immune function. The heart (Choice A), bronchi (Choice B), and esophagus (Choice D) are not directly involved in the immune system's functions. The heart pumps blood, the bronchi are part of the respiratory system, and the esophagus is responsible for transporting food to the stomach.

Correct Answer: B

Rationale: The correct answer is B: Hyoid. The hyoid bone is the only bone in the body that does not articulate with any other bones. It is located in the neck and supports the tongue and other muscles involved in swallowing and speech. The scapula articulates with the clavicle and humerus, the radius with the ulna and humerus, and the femur with the pelvis and tibia. Choices A, C, and D are incorrect because they all articulate with other bones in the body.

Correct Answer: A

Rationale: The larynx, also known as the voice box, is a crucial structure in the respiratory system. It is located in the upper part of the trachea and houses the vocal cords. The larynx plays a key role in producing sound and protecting the trachea by closing during swallowing to prevent food from entering the airway. This makes the larynx the correct answer in this context. The trachea (Choice B) is a respiratory structure that connects the larynx to the lungs, allowing air to pass through. The pharynx (Choice C) is a shared pathway for both air and food, located at the back of the throat. The esophagus (Choice D) is part of the digestive system, responsible for transporting food from the mouth to the stomach. Therefore, Choices B, C, and D are not located in the respiratory system.