Infection and Immunity

Question 1

1. What is the first barrier for infection?

Answer 1

Innate immune system

Question 2

2. What are the components of innate immunity

Answer 2

1. Anatomical structures-skin, mucous membranes,
2. inhibitory secretions
3. antimicrobial factors
4. Phagocytic cells

Question 3

What happens when an infectious agent enters the tissues?
Or what is an adaptive immune response?

Answer 3

Material from the invading pathogen can be presented to lymphocytes by phagocytic cells such as macrophages.

These lymphocytes then undergo functional changes, proliferate, and secrete soluble factors which promote the involvement of other cells of the immune system to contain the infection.

Question 4

What mediates the presentation of invading cells to the lymphocytes

Answer 4

Macrophages

Question 5

What are the components of immune system?

Answer 5

Innate, non-specific barrier
Specific combined with immunological memory

Question 6

Is Immune response confined only to the infectious agents?

Answer 6

False

Question 7

What are the anatomical structures and mechanical activity involved in innate immunity?

Answer 7

Skin
Mucous membranes
Mucociliary clearance
Flushing activity of urine and lacrimal secretions
Peristalsis
Coughing and sneezing

Question 8

What are the inhibitory secretions involved in innate immunity?

Answer 8

Gastric acid
Fatty acids in skin
Bile
Mucus

Question 9

What are the cells involved in innate immunity?

Answer 9

Neutrophils
Monocytes
Macrophages
Dendritic cells
NK cells
Eosinophils
Mast cells

Question 10

What are the antimicrobial factors of innate immunity?

Answer 10

Complement
Lysozymes
Interferons
Acute phase proteins
Mannose-binding lectin
Properdin
Lactoperoxidase
Lactoferrin
Transferrin
Peptides such as defensins
Degradative enzymes
Toxic free radicals
Cytokines
Chemotactic factors

Question 11

Is normal flora associated with non-specific immunity

Answer 11

Yes, indirectly by gently challenging the naive immune system at young age
By helping in digestion especially in ruminants

Question 12

What are the main antigen presenting cells?

Answer 12

Macrophages
Dendritic cells

Question 13

Microorganisms that compete successfully for particular sites gradually form a stable normal flora

Answer 13

True

Question 14

How does normal flora compete with pathogenic microorganisms?

Answer 14

Competition for nutrients
Formation of inhibitory substances
Attachment to receptors on cell surfaces- prevents colonization of invading pathogens

Question 15

Will Candida albicans overgrow in the absence of resident/normal flora?

Answer 15

True

Question 16

Stem cells have the remarkable potential to renew themselves.

They can develop into many different cell types in the body during early life and growth.

Answer 16

True

True

Question 17

What are the two main stem cells?

Answer 17

Pluripotent” stem cells (embryonic stem cells and induced pluripotent stem cells)

Nonembryonic or somatic stem cells (commonly called “adult” stem cells)

Question 18

Are pluripotent stem cells are undifferentiated?

Answer 18

True

Question 19

What are the three know accessible source of autologous adult stem cells?

Answer 19

Bone marrow
Adipose tissue
Blood