hid ?

Oropharyngeal in children " 2-3 weeks "
In adults " 4-5 Days "
Genital " 3 weeks "
Varicella " incubation period " 10-21 Days "
Zoster " 2-4 weeks "

Microbiology - Lecture 8 ↓

📍Innate immunity

1. What is the primary characteristic of innate immunity?
- A) It is highly specific to pathogens.
- B) It lacks immunologic memory.
- C) It provides long-term protection against reinfection.
- D) It is only active after adaptive immunity fails.
Correct Answer: B) It lacks immunologic memory.

2. Which of the following best describes adaptive immunity?
- A) Rapid but nonspecific response to pathogens.
- B) A defense system that includes skin and mucous membranes.
- C) A pathogen-specific response with immunologic memory.
- D) The first line of defense against infections.
Correct Answer: C) A pathogen-specific response with immunologic memory.

3. When is the adaptive immune response typically activated?
- A) Before innate immunity responds.
- B) Only in the presence of vaccines.
- C) When innate immunity fails to eliminate the pathogen.
- D) Exclusively in autoimmune diseases.
Correct Answer: C) When innate immunity fails to eliminate the pathogen.

4. Which of the following is a key component of the innate immune barrier?
- A) Antibodies
- B) T-cells
- C) Skin and mucous membranes
- D) Memory B-cells
Correct Answer: C) Skin and mucous membranes.

5. What is the main functional difference between innate and adaptive immunity?
- A) Innate immunity is slower but more specific.
- B) Adaptive immunity lacks memory.
- C) Innate immunity is nonspecific, while adaptive immunity is specific and has memory.
- D) Adaptive immunity is always active, whereas innate immunity requires activation.
Correct Answer: C) Innate immunity is nonspecific, while adaptive immunity is specific and has memory.

📍Innate Immunity – Mechanical Barriers :

1. Which of the following is a key antimicrobial property of sweat and sebaceous secretions?
- A) High pH that promotes bacterial growth
- B) Presence of fatty acids and acidic pH
- C) Production of antibodies
- D) Activation of T-cells
Correct Answer: B) Presence of fatty acids and acidic pH

2. How do mucous membranes contribute to innate immunity?
- A) By producing antibodies against pathogens
- B) By sloughing off rapidly, preventing microbial attachment
- C) By activating adaptive immune responses
- D) By storing memory B-cells
Correct Answer: B) By sloughing off rapidly, preventing microbial attachment

3. Which structure in the respiratory tract helps remove inhaled particles?
- A) Low stomach pH
- B) Mucociliary escalator in the trachea
- C) Gut flora
- D) Urinary flow
Correct Answer: B) Mucociliary escalator in the trachea*

4. What is the role of the low pH in the stomach as part of innate immunity?
- A) Promotes bacterial growth
- B) Denatures proteins and kills microorganisms
- C) Enhances mucus production
- D) Activates T-cell responses
Correct Answer: B) Denatures proteins and kills microorganisms

5. Which of the following is NOT a mechanical barrier in innate immunity?
- A) Peristalsis in the gastrointestinal tract
- B) Continuous urine flow in the urinary tract
- C) Production of antibodies by B-cells
- D) Cough reflex preventing pathogen aspiration
Correct Answer: C) Production of antibodies by B-cells(This is part of adaptive immunity, not innate barriers.)

📍Innate Immunity – Chemical and Biological Barriers :

1. What is the primary function of lysozyme in innate immunity?
- A) Neutralizing stomach acid
- B) Breaking down bacterial peptidoglycan, creating holes in cell walls
- C) Activating T-cells for adaptive immunity
- D) Producing antibodies against viruses
Correct Answer: B) Breaking down bacterial peptidoglycan, creating holes in cell walls

2. How does the stomach contribute to chemical barrier defense?
- A) By secreting fatty acids to moisturize the skin
- B) By producing concentrated hydrochloric acid to kill bacteria
- C) By releasing IgA to block pathogen adhesion
- D) By hosting normal microbiota to compete with pathogens
Correct Answer: B) By producing concentrated hydrochloric acid to kill bacteria

3. What role does normal microbiota play in biological barriers?
- A) They produce antibodies to target specific pathogens.
- B) They compete with pathogenic microorganisms, limiting their growth.
- C) They break down peptidoglycan in bacterial cell walls.
- D) They increase stomach pH to promote digestion.
Correct Answer: B) They compete with pathogenic microorganisms, limiting their growth.

4. Which of the following is an example of a biological barrier in the vagina?**
- A) High pH maintained by Escherichia coli
- B) Acidic pH maintained by normal lactobacilli
- C) Lysozyme secretion from tear glands
- D) Mucociliary escalator in the respiratory tract
Correct Answer: B) Acidic pH maintained by normal lactobacilli

5. How does secretory IgA (immunoglobulin A) function in mucosal immunity?
- A) By killing bacteria through enzymatic action
- B) By binding pathogens and toxins to prevent epithelial adhesion
- C) By acidifying the stomach to denature proteins
- D) By competing with normal microbiota for resources
Correct Answer: B) By binding pathogens and toxins to prevent epithelial adhesion

📍Innate immune cells :

1. Which of the following is NOT considered a professional phagocytic cell in innate immunity?
A) Alveolar macrophages
B) Kupffer cells
C) Neutrophils
D) B lymphocytes
Answer: D) B lymphocytes (These are part of adaptive immunity)

2. What is the primary function of natural killer (NK) cells in innate immunity?
A) Phagocytosing extracellular bacteria
B) Producing antibodies against viruses
C) Killing virus-infected and tumor cells
D) Presenting antigens to T cells
Answer: C) Killing virus-infected and tumor cells

3. Where would you typically find Kupffer cells as resident macrophages?
A) Lungs
B) Liver
C) Skin
D) Brain
Answer: B) Liver

4. Which innate immune cell plays a dual role as both a phagocyte and an antigen-presenting cell?
A) Neutrophils
B) Natural killer cells
C) Dendritic cells
D) Basophils
Answer: C) Dendritic cells

5. What is the main characteristic of neutrophils in the innate immune response?
A) They reside permanently in tissues
B) They are primarily involved in allergic reactions
C) They migrate to sites of damage and contribute to inflammation
D) They produce large amounts of antibodies
Answer: C) They migrate to sites of damage and contribute to inflammation