Which of the following is considered a primary lymphoid organ?
lymph node
tonsils
appendix
spleen
thymus
The Correct Answer is E
A. Lymph node: Lymph nodes are secondary lymphoid organs where lymphocytes encounter antigens and mount immune responses. They do not provide the environment for initial lymphocyte development or immunocompetence.
B. Tonsils: Tonsils are secondary lymphoid tissues that trap pathogens entering through the oral and nasal cavities. They function in immune surveillance but do not serve as sites for lymphocyte maturation.
C. Appendix: The appendix contains lymphoid tissue that contributes to immune defense, but it is a secondary lymphoid structure involved in antigen exposure, not lymphocyte development.
D. Spleen: The spleen filters blood and supports immune responses to blood-borne antigens. It is a secondary lymphoid organ and does not generate immunocompetent lymphocytes initially.
E. Thymus: The thymus is a primary lymphoid organ where T lymphocytes mature and acquire immunocompetence. It provides the essential environment for T cell differentiation before they enter circulation and secondary lymphoid tissues.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
A. Veins:Veins primarily function as capacitance vessels, returning blood to the heart and serving as blood reservoirs. They are not specialized for nutrient or gas exchange because their walls are thicker and less permeable.
B. Arteries:Arteries carry blood away from the heart and help maintain blood pressure, but their thick muscular walls prevent direct exchange of nutrients and gases with surrounding tissues. Their primary role is transport and pressure regulation.
C. Capillaries:Capillaries are the smallest blood vessels with thin walls composed of a single layer of endothelial cells. This structure allows efficient exchange of oxygen, carbon dioxide, nutrients, and waste products between blood and tissue cells, making them the primary site of exchange.
D. Arterioles:Arterioles regulate blood flow into capillary beds through vasoconstriction and vasodilation. While they influence perfusion, they are not the primary site for actual exchange of gases and nutrients.
Correct Answer is E
Explanation
A. Artificial passive immunity:Artificial passive immunity involves the transfer of preformed antibodies, such as through immunoglobulin injections. Vaccination does not provide preformed antibodies, so this does not apply.
B. Artificial specific immunity:While vaccines do target specific pathogens, the term is not precise in immunology. Vaccination specifically stimulates the adaptive immune system to produce its own antibodies and memory cells, so a more accurate description is needed.
C. Natural active immunity:Natural active immunity occurs when an individual is exposed to a pathogen naturally and mounts their own immune response. Vaccination provides antigen exposure without natural infection, so it is not natural.
D. Natural passive immunity:Natural passive immunity occurs when antibodies are transferred from mother to child, such as through breast milk. Vaccines do not provide immunity via maternal antibodies.
E. Artificial active immunity:Vaccination introduces antigens into the body, prompting the immune system to produce its own antibodies and memory cells. This is an example of artificial active immunity, as the immunity is actively generated through an artificial intervention.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.