The first nurse researcher is

Correct Answer: C

Rationale: Florence Nightingale is recognized as the first nurse researcher for her pioneering statistical analysis of hospital mortality during the Crimean War. 'Florence Nightingale,' is correct, as her work (e.g., Notes on Nursing) laid foundations for evidence-based practice, per nursing history (e.g., Judd's Nursing Theories). 'Calista Roy,' and 'Betty Neuman,' developed later models (adaptation, systems). 'Dorothea Orems,' focused on self-care theory, not early research. Nightingale's use of data to improve care marks her as the originator, making C the precise answer.

Correct Answer: B

Rationale: The shoulder's ball-and-socket joint allows humeral rotation. 'Ball and socket,' is correct, the glenohumeral joint's structure, per anatomy (e.g., Tortora). 'Hinge,' (e.g., elbow) limits rotation. 'Condylar,' (e.g., knee) is less mobile. 'Saddle,' (e.g., thumb) is specific. Ball-and-socket's multidirectional range makes B the precise answer.

Correct Answer: A

Rationale: Valves in blood vessels prevent backflow, aiding venous return against gravity, but capillaries lack them due to their role in exchange, not directional flow. 'Capillaries,' is correct, as per anatomy texts like Moore's Clinically Oriented Anatomy, which note valves in veins and some venules. 'Veins,' have valves, especially in limbs. 'Venules,' may have valves in larger ones transitioning to veins. 'Vena cavae,' lack valves, but the question's focus on typical presence points to capillaries' exception. Capillaries' thin walls and continuous flow for nutrient exchange exclude valves, making A the accurate answer, distinct from the venous system's structural adaptations.

Correct Answer: B

Rationale: Sperm, the male reproductive cells, are produced in the seminiferous tubules of the testes. 'Seminiferous tubules,' is correct, per reproductive physiology texts like Tortora, where spermatogenesis occurs. 'Epididymis,' stores and matures sperm. 'Vas deferens,' transports sperm. 'Prostate gland,' produces seminal fluid. The tubules' role as the site of sperm cell formation distinguishes B as the accurate answer, foundational to male fertility.

Correct Answer: C

Rationale: Vitamin K is essential for synthesizing clotting factors (e.g., prothrombin) in the liver. 'Vitamin K,' is correct, per physiology texts like Guyton, preventing bleeding disorders. 'Vitamin A,' aids vision. 'Vitamin B,' encompasses metabolic coenzymes, not clotting. 'Vitamin D,' regulates calcium. Vitamin K's specific role in coagulation cascades makes C the accurate answer.