Nokea
What is the medical term for a blood clot that forms within a blood vessel?
- A. Thrombosis
- B. Embolus
- C. Hemorrhage
- D. Hemostasis
Correct Answer: A
Rationale: The correct answer is A: Thrombosis. Thrombosis refers to the formation of a blood clot within a blood vessel. The process involves the coagulation of blood components to form a clot. This can lead to blockages in blood vessels, potentially causing serious health issues like stroke or heart attack.
Choice B: Embolus refers to a blood clot that has traveled from its original site and lodged in a different blood vessel. Choice C: Hemorrhage is the medical term for bleeding. Choice D: Hemostasis refers to the body's process of stopping bleeding, not the formation of a blood clot.
You may also like to solve these questions
What effect does the action of the complement system have on inflammation?
- A. Modifies the inflammatory response to prevent stimulation of pain
- B. Increases body temperature, resulting in destruction of microorganisms
- C. Produces prostaglandins and leukotrienes that increase blood flow, edema, and pain
- D. Increases inflammatory responses of vascular permeability, chemotaxis, and phagocytosis
Correct Answer: D
Rationale: The complement system enhances inflammation by increasing vascular permeability, attracting immune cells (chemotaxis), and promoting phagocytosis of pathogens or debris.
The clonal selection theory explains:
- A. That one given lymphocyte expresses multiple antigen receptors with different specificity
- B. That antigens influence the generation of antigen receptors during lymphocyte development
- C. How the immune response to an antigen increases the number of lymphocytes specific for that antigen
- D. The increase in blood neutrophils observed during bacterial infections
Correct Answer: C
Rationale: Rationale:
1. Clonal selection theory states that specific lymphocytes are activated by antigens.
2. Upon activation, these lymphocytes proliferate to form a clone of cells specific to the antigen.
3. This increases the number of lymphocytes specific for the antigen.
4. Choice C correctly aligns with the essence of clonal selection theory.
Summary:
A: Incorrect - Clonal selection theory does not involve a single lymphocyte expressing multiple antigen receptors.
B: Incorrect - Antigens do not influence the generation of antigen receptors, but rather activate specific lymphocytes.
D: Incorrect - Clonal selection theory focuses on lymphocyte response to antigens, not neutrophil increase during infections.
What is the name of a tumor from the embryonal mesoderm tissue of origin located in the anatomic site of the meninges that has malignant behavior?
- A. Meningitis
- B. Meningioma
- C. Meningocele
- D. Meningeal sarcoma
Correct Answer: D
Rationale: Meningeal sarcoma is a malignant tumor originating from the mesodermal tissue of the meninges.
Why do we constantly need new flu vaccines?
- A. Because flu viruses mutate frequently due to their error-prone RNA polymerase
- B. Because completely new variants can be created from an assortment of previously circulating strains due the segmented nature of the viral genome
- C. Because antibodies generated in vaccinated people are short-lived and need to be generated again with a new vaccine injection
- D. Both A and B are correct
Correct Answer: D
Rationale: The correct answer is D. Choice A is correct because flu viruses mutate frequently due to their error-prone RNA polymerase, leading to new strains. Choice B is correct because the segmented nature of the viral genome allows for reassortment of different strains, creating completely new variants. Therefore, new vaccines are needed to target these evolving strains. Choice C is incorrect as the need for new vaccines is primarily driven by the genetic variability of the virus, not solely by the short-lived nature of antibodies. Thus, choices A and B together provide a comprehensive explanation for the constant need for new flu vaccines.
Which type of cell produces antibodies?
- A. Helper T cells
- B. Plasma cells
- C. Cytotoxic T cells
- D. Regulatory T cells
Correct Answer: B
Rationale: The correct answer is B: Plasma cells. Plasma cells are a type of white blood cell that produces antibodies in response to antigens. They are essential in the immune response to help fight off infections and other diseases. Helper T cells (A) assist other immune cells but do not directly produce antibodies. Cytotoxic T cells (C) are responsible for killing infected cells, not producing antibodies. Regulatory T cells (D) help regulate the immune response but do not produce antibodies. In summary, only plasma cells are specifically designed to produce antibodies in the immune system.