Correct Answer: C

Rationale: Prolactin is the hormone responsible for stimulating milk production in the breasts during lactation. It is produced by the pituitary gland and plays a crucial role in the initiation and maintenance of lactation. While norepinephrine, antidiuretic hormone, and oxytocin have roles in various physiological processes, they do not directly stimulate milk production. Therefore, the correct answer is prolactin.

Correct Answer: A

Rationale: Hormones are signaling molecules produced by glands that travel through the bloodstream to target cells, exerting control over processes like growth, differentiation, and metabolism. Neurons are nerve cells responsible for transmitting electrical impulses. Glands are structures that secrete substances like hormones. Second messengers are molecules involved in intracellular signal transduction pathways, amplifying and transmitting signals from the cell membrane to the nucleus.

Correct Answer: A

Rationale: An adult typically inhales around 500 mL of air in an average breath. This volume is known as tidal volume, representing the amount of air inspired or expired during normal breathing. Tidal volume plays a crucial role in efficient gas exchange in the lungs and maintaining adequate oxygen levels in the body. It is essential for proper respiratory function and ensuring the body receives the necessary oxygen for cellular respiration and overall metabolism.

Correct Answer: D

Rationale: Plasma cells are a type of white blood cell specialized in producing and secreting antibodies. Antibodies, also known as immunoglobulins, are vital components of the immune system that help recognize and neutralize pathogens. When the body encounters an antigen, plasma cells are activated to produce and secrete antibodies specific to that antigen. These antibodies bind to the pathogen, marking it for destruction by other immune cells. Therefore, plasma cells are the correct answer as they are specifically designed to produce and secrete antibodies to fight infections.

Correct Answer: D

Rationale: Filtration in the kidneys is primarily driven by blood pressure. The glomerulus filters blood under pressure, allowing small molecules and fluids to pass through into the renal tubules while retaining larger molecules like proteins. Osmosis, smooth muscle contraction, and peristalsis do play roles in kidney function, but blood pressure is the main force responsible for the initial filtration process.