Nokea
The papillary layer of the skin is part of the:
- A. epidermis
- B. dermis
- C. hypodermis
- D. subcutaneous layer
Correct Answer: B
Rationale: The correct answer is B: dermis. The papillary layer is located in the dermis, specifically at the junction with the epidermis. It contains capillaries, lymphatics, and sensory receptors, contributing to the skin's strength and elasticity. The epidermis (choice A) is the outermost layer of the skin, while the hypodermis (choice C) and subcutaneous layer (choice D) are deeper layers beneath the dermis, primarily composed of fat cells and connective tissue. Therefore, the papillary layer is part of the dermis, making choice B the correct answer.
You may also like to solve these questions
Which of the following statements for S. Aureus is FALSE
- A. it is always susceptible for penicillin
- B. around its colonies there is a beta hemolytic zone
- C. it produces hemolysins, leucocidins, enterotoxins
- D. has a positive catalase reaction
Correct Answer: A
Rationale: The correct answer is A because Staphylococcus aureus can develop resistance to penicillin over time due to the production of beta-lactamase enzymes. This resistance mechanism makes it no longer susceptible to penicillin. The other choices are correct: B) S. aureus can produce beta hemolysis, C) it produces various toxins like hemolysins, leucocidins, and enterotoxins, and D) it shows a positive catalase reaction due to the presence of catalase enzyme that converts hydrogen peroxide to water and oxygen.
The development of polioviruses on cell cultures is characterized by:
- A. Cytopathic effect
- B. Cytotoxic effect
- C. Cytolytic effect
- D. They Don't Change The Cell Cultures
Correct Answer: A
Rationale: The correct answer is A: Cytopathic effect. This is because polioviruses cause visible changes in infected cells, leading to cell damage and death, known as cytopathic effect. This is a key characteristic of viral infection. Choice B (Cytotoxic effect) is incorrect as it refers to the toxicity of a substance to cells, not the specific effect of polioviruses. Choice C (Cytolytic effect) is incorrect as it specifically refers to cell lysis, which is not the primary mechanism of poliovirus infection. Choice D (They Don't Change The Cell Cultures) is incorrect because polioviruses do indeed cause changes in cell cultures due to their cytopathic effect.
A bacteriological laboratory tests canned meat for botulinum toxin. Extract of the tested material and ABE botulinum antitoxin serum was introduced into the test group of mice; a control group of mice received the extract without antibotulinic serum. What serological reaction was used?
- A. Neutralization
- B. Precipitation
- C. Complement binding
- D. Double immunodiffusion
Correct Answer: A
Rationale: The correct answer is A: Neutralization. In this experiment, the ABE botulinum antitoxin serum is introduced along with the extract to neutralize the botulinum toxin. This is a specific type of serological reaction where the antitoxin serum binds to and neutralizes the toxin, preventing it from causing harm.
Summary:
- B: Precipitation involves the formation of visible insoluble complexes, which is not the case in this experiment.
- C: Complement binding involves the activation of complement proteins, which is not the main mechanism at play here.
- D: Double immunodiffusion is a technique to detect the presence of specific antigens or antibodies, but it is not directly related to the neutralization of toxins as seen in this experiment.
A 45-year-old patient has foul-smelling diarrhea. Stool examination revealed large ciliated protozoa with a kidney-shaped macronucleus. What is the causative agent?
- A. Balantidium coli
- B. Entamoeba histolytica
- C. Giardia lamblia
- D. Trichomonas hominis
Correct Answer: A
Rationale: The correct answer is A: Balantidium coli. This large ciliated protozoa with a kidney-shaped macronucleus is characteristic of Balantidium coli, an intestinal parasite known to cause foul-smelling diarrhea in humans. Balantidium coli is the only option among the choices that fits this specific description. Entamoeba histolytica causes amoebic dysentery, Giardia lamblia causes giardiasis, and Trichomonas hominis is a non-pathogenic protozoa found in the intestinal tract. Therefore, based on the morphology described in the question, Balantidium coli is the correct causative agent.
Gram-negative diplococci were isolated from a urethral discharge in a male patient with painful urination. What is the causative agent?
- A. Neisseria gonorrhoeae
- B. Escherichia coli
- C. Proteus vulgaris
- D. Klebsiella pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Neisseria gonorrhoeae. This bacterium is a gram-negative diplococci commonly associated with gonorrhea, which presents with symptoms like painful urination. Neisseria gonorrhoeae is known to infect the urethra in males. Escherichia coli, Proteus vulgaris, and Klebsiella pneumoniae are all gram-negative bacteria, but they are not typically associated with urethral discharge or gonorrhea. E. coli is commonly associated with urinary tract infections, Proteus vulgaris with wound infections, and Klebsiella pneumoniae with pneumonia and other respiratory infections. Therefore, based on the patient's symptoms and the characteristics of the bacteria, Neisseria gonorrhoeae is the most appropriate causative agent in this case.