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

📍 Adaptive immunity :

1. What triggers the activation of adaptive immunity?
A) It is always active from birth
B) When innate immunity fails to control infection
C) Only during autoimmune diseases
D) When the body temperature rises above 38°C
Answer: B) When innate immunity fails to control infection

2. Which of the following best describes active immunity?
A) Transfer of ready-made antibodies from mother to fetus
B) Immunity developed after receiving antiserum injection
C) Resistance developed after antigen exposure (infection/vaccine)
D) Short-term protection from breast milk
Answer: C) Resistance developed after antigen exposure (infection/vaccine)

3. What is the primary function of HLA (Human Leukocyte Antigen) system?
A) Produce antibodies against pathogens
B) Differentiate between self and non-self antigens
C) Phagocytose foreign particles
D) Activate complement proteins
Answer: B) Differentiate between self and non-self antigens

4. Which property of adaptive immunity allows for stronger and faster response upon re-exposure?
A) Specificity
B) Memory
C) Self-recognition
D) Diversity
Answer: B) Memory

5. What type of immunity is transferred through placenta from mother to baby?
A) Active natural immunity
B) Active artificial immunity
C) Passive natural immunity
D) Passive artificial immunity
Answer: C) Passive natural immunity

6. Which cells are primarily responsible for immunological memory in adaptive immunity?
A) Neutrophils and macrophages
B) Memory T cells and B cells
C) Natural killer cells
D) Dendritic cells
Answer: B) Memory T cells and B cells

7. What is the key difference between active and passive immunity?
A) Active immunity is temporary, passive is permanent
B) Active involves antibody production, passive involves receiving antibodies
C) Active immunity only works against viruses
D) Passive immunity creates memory cells
Answer: B) Active involves antibody production, passive involves receiving antibodies

8. Which of the following is an example of passive artificial immunity?
A) Recovery from chickenpox
B) Maternal antibodies through breast milk
C) Tetanus immunoglobulin injection
D) MMR vaccination
Answer: C) Tetanus immunoglobulin injection

9. What characteristic of adaptive immunity enables targeted response to specific antigens?
A) Specificity
B) Inflammatory response
C) Phagocytic ability
D) Complement activation
Answer: A) Specificity

10. Which immune cells are primarily responsible for attacking intracellular pathogens in adaptive immunity?
A) B cells
B) T cells
C) Macrophages
D) Eosinophils
Answer: B) T cells

📍Cell-mediated and antibody-mediated immunity :

1. What is the primary function of cytotoxic (CD8+) T cells in cell-mediated immunity?
A) To produce antibodies against extracellular pathogens
B) To destroy virus-infected cells and tumor cells
C) To activate macrophages through cytokine secretion
D) To neutralize toxins in the bloodstream
Answer: B) To destroy virus-infected cells and tumor cells

2. Which of the following best describes the role of helper (CD4+) T cells in adaptive immunity?
A) They directly kill infected cells
B) They are required for activating both B cells and cytotoxic T cells
C) They produce antibodies against specific antigens
D) They primarily target extracellular bacteria
Answer: B) They are required for activating both B cells and cytotoxic T cells

3. What is the final differentiation product of activated B cells in the humoral immune response?
A) Memory T cells
B) Natural killer cells
C) Plasma cells that produce antibodies
D) Dendritic cells
Answer: C) Plasma cells that produce antibodies

4. Which immune mechanism is most effective against extracellular pathogens and their toxins?
A) Cell-mediated immunity through cytotoxic T cells
B) Antibody-mediated immunity through B cells
C) Phagocytosis by neutrophils
D) NK cell activity
Answer: B) Antibody-mediated immunity through B cells

5. What is the function of antibodies in neutralizing pathogens?
A) Directly lysing infected cells
B) Producing cytokines to activate T cells
C) Blocking the activity of toxins and preventing viral entry
D) Presenting antigens to dendritic cells
Answer: C) Blocking the activity of toxins and preventing viral entry

📍B-cell receptors and the complement system :

1. What is the primary function of B-cell receptors (BCRs)?
A) To phagocytose pathogens
B) To serve as antigen-specific recognition molecules
C) To produce complement proteins
D) To activate cytotoxic T cells
Answer: B) To serve as antigen-specific recognition molecules

2. How many different antigens can a single B cell recognize?
A) Multiple unrelated antigens
B) Only one antigen or closely related antigens
C) All antigens present in the body
D) Only viral antigens
Answer: B) Only one antigen or closely related antigens

3. Which of the following is NOT a major outcome of complement activation?
A) Cytolysis
B) Chemotaxis
C) Antibody production
D) Opsonization
Answer: C) Antibody production

4. What is the correct sequence of classical complement pathway activation?
A) C1-C2-C3-C4-C5-C6-C7-C8-C9
B) C1-C4-C2-C3-C5-C6-C7-C8-C9
C) C3-C5-C6-C7-C8-C9-C1-C2-C4
D) C9-C8-C7-C6-C5-C4-C3-C2-C1
Answer: B) C1-C4-C2-C3-C5-C6-C7-C8-C9

5. Which complement function involves coating pathogens to enhance phagocytosis?
A) Cytolysis
B) Chemotaxis
C) Opsonization
D) Anaphylatoxins
Answer: C) Opsonization

6. What is the biological effect of anaphylatoxins?
A) Direct killing of tumor cells
B) Attracting neutrophils to infection sites
C) Increasing vascular permeability
D) Presenting antigens to T cells
Answer: C) Increasing vascular permeability

7. Which component bridges innate and adaptive immunity?
A) B cells only
B) T cells only
C) Complement system
D) Natural killer cells
Answer: C) Complement system

8. What occurs during complement-mediated cytolysis?
A) Enhanced phagocytosis
B) Formation of membrane attack complex
C) Release of histamine
D) Activation of B cells
Answer: B) Formation of membrane attack complex

9. Which immune process involves attraction of phagocytes to infection sites?
A) Opsonization
B) Chemotaxis
C) Neutralization
D) Agglutination
Answer: B) Chemotaxis

10. What type of molecule serves as the B-cell receptor?
A) MHC class II
B) T-cell receptor
C) Surface immunoglobulin
D) Complement protein C3
Answer: C) Surface immunoglobulin

Physiology : Everytime you try to forget who I am I'll be right there to remind you again 🤭

Hype(r)thyroidism = G(r)ave's
Hyp(o)thyroidism = Hashim(o)t(o)'s

Pharmacognocy :
Lecture 1
Lecture 2
Lecture 3
Lecture 4
Lecture 5
Lecture 6
Lecture 7