Nokea
The human retina contains rods and cone which are able to
- A. convert the photo power to the chemical power
- B. absorption of ultraviolet
- C. convert photo power to electrical form and send action potentials to the brain
- D. absorption of infrared
Correct Answer: C
Rationale: The correct answer is C because rods and cones in the human retina convert light energy into electrical signals through phototransduction, which are then sent as action potentials to the brain via the optic nerve. This process allows for visual information to be transmitted and processed by the brain. Choice A is incorrect as it refers to the conversion of light energy to chemical energy, which is not the primary function of rods and cones. Choice B is incorrect as rods and cones do not specifically absorb ultraviolet light. Choice D is incorrect as rods and cones do not absorb infrared light.
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What is one of the immune system's critical functions in cancer?
- A. Promoting cell growth
- B. Fighting cancer by targeting abnormal cells
- C. Enhancing pathogen resistance
- D. Stimulating autoimmune responses
Correct Answer: B
Rationale: The correct answer is B: Fighting cancer by targeting abnormal cells. The immune system plays a crucial role in cancer by identifying and eliminating abnormal cells that can develop into tumors. This process is known as immunosurveillance. Through mechanisms like T cells and natural killer cells, the immune system can detect and destroy cancerous cells before they can grow and spread. This function is essential in preventing the development and progression of cancer.
Choices A, C, and D are incorrect:
A: Promoting cell growth - The immune system does not promote cell growth in cancer; rather, it regulates and suppresses the growth of abnormal cells.
C: Enhancing pathogen resistance - While the immune system does enhance resistance against pathogens, this is not its critical function in cancer.
D: Stimulating autoimmune responses - Autoimmune responses involve the immune system attacking healthy cells, not targeting cancerous cells.
Mutations in which of the following genes are considered a risk factor for Crohn's disease?
- A. TLR-4
- B. NOD2
- C. NADPH oxidase
- D. IL-2
Correct Answer: B
Rationale: The correct answer is B: NOD2. Mutations in the NOD2 gene have been strongly associated with an increased risk of Crohn's disease. NOD2 is involved in the immune response to bacteria in the gut, and mutations in this gene can lead to dysregulation of the immune system, contributing to the development of Crohn's disease.
A: TLR-4 is involved in the recognition of bacterial components but mutations in this gene are not strongly linked to Crohn's disease.
C: NADPH oxidase is important for the production of reactive oxygen species in immune cells but mutations in this gene are not known to be a risk factor for Crohn's disease.
D: IL-2 is a cytokine involved in immune regulation but mutations in this gene are not associated with an increased risk of Crohn's disease.
Which of the following concerned with Leishmania is NOT true
- A. Meditated by IgE
- B. Is a unicellular parasite
- C. Activation of macrophages is essential for killing the parasite
- D. Escapes host immune attack by hiding inside neutrophils
Correct Answer: a
Rationale: The correct answer is A: Mediated by IgE. Leishmania infection is not primarily mediated by IgE antibodies. The immune response against Leishmania involves T cells, macrophages, and cytokines. IgE is not a major player in the defense against Leishmania. Choices B, C, and D are incorrect because Leishmania is indeed a unicellular parasite, activation of macrophages is essential for killing the parasite, and Leishmania can hide inside neutrophils to escape the host immune attack.
Crohn's disease is
- A. A chronic inflammatory disease caused by defective NFκB signaling
- B. Associated with mutations of NLRP3
- C. Associated with defective production of ROS
- D. A chronic inflammatory disease associated with overgrowth of gut commensal flora
Correct Answer: D
Rationale: Step-by-step rationale for why answer D is correct:
1. Crohn's disease is characterized by chronic inflammation in the gastrointestinal tract.
2. It is associated with dysregulation of the immune response to gut flora.
3. Overgrowth of gut commensal flora can trigger and exacerbate inflammation in Crohn's disease.
4. Choices A, B, and C do not directly relate to the pathophysiology of Crohn's disease, making them incorrect.
As the nurse manager in a public health department,you are responsible for developing a plan to reduce the incidence of infection with the human immunodeficiency virus (HIV) in the community. Which nursing action is best delegated to health assistants working for the agency?
- A. Supply injection drug users with bleach solution for cleaning needles and syringes.
- B. Provide pretest and post-test counseling to those patients who are seeking HIV testing.
- C. Educate high-risk community members about the use of condoms in HIV prevention.
- D. Determine which population groups to target for education based on community assessment.
Correct Answer: A
Rationale: Health assistants can effectively distribute bleach solutions to injection drug users as part of harm reduction strategies. Pretest and post-test counseling education on condom use and community assessment require more advanced training and are typically responsibilities of registered nurses or other healthcare professionals.