Function and Organization of Immune System

Question 1

What is Immunology?

Answer 1

Study of molecules, cells, organs responsible for responding to foreign materials

Question 2

Immune System Organization

Answer 2

Immune cells > lymphoid organisms > immune arms

Question 3

Innate Immune System

Answer 3

Non-specific: responds to groups of pathogens, not specific pathogens
Fast: capacity for maximum response, many cells, cells deployed fast
No memory: same response if exposed to the same pathogen, not augmented

Neutrophils are a part of this, 1st line of defense

Question 4

Adaptive Immune System

Answer 4

Specific: responds to specific pathogen/foreign element
Slower: fewer cells potential to respond, need to be activated first
Memory: exposed to same pathogen, response is faster and stronger

Question 5

Macrophages (Macs)

Answer 5

Foot soldiers and informants
Kill and present pathogens, clean-up

Innate

Question 6

Dendritic Cells (DCs)

Answer 6

Foot soldiers and informants
Kill and present pathogens to adaptive immune cells

Innate

Question 7

CD4 T Helper (Th) Lymphocytes

Answer 7

Commanders, direct or stop B cells and CD8 Tc cells

“Help” guide immune response

Adaptive

Question 8

CD8 T Cytotoxic (Tc) Lymphocytes

Answer 8

Comman-dos
Kill infected cells

Adaptive

Question 9

B Lymphocytes

Answer 9

Produce antibodies that neutralize/kill pathogens

Adaptive

Question 10

Immunogens

Answer 10

Any substance that elicits immune response
Not all the same
Larger/more complex = stronger
- proteins, polysaccharides = better due to amino acid sequences, stronger binding to receptors on B/T cells

Question 11

Antigens

Answer 11

Any substance that can be bound by an antibody or T cell receptor

Antibody antigens: all biological molecules

T cell antigens: linear peptides in context of an MHC molecule

Question 12

Location of Immune Cells

Answer 12

Blood (good for low invasiveness samples)
Tissue (pathogen detection/clearance)
Lymphatics (transport of pathogens to LN/Sp)
Lymphoid organs (site activation)

Question 13

Increase in Total Blood Leukocytes

What could cause it?

Answer 13

Infection

Question 14

Increase in Neutrophils

What could cause it?

Answer 14

Bacterial infection

Question 15

Increase in Monocytes

What could cause it?

Answer 15

Viral, fungal, Mtb infections

Question 16

Increase in T/B cells

What could cause it?

Answer 16

Multiple pathogen types

Question 17

Primary Lymphoid Organs

Military school!

Answer 17

Thymus + bone marrow

Site of production and maturation of immune cells

Question 18

Secondary Lymphoid Organs

Field bases

Answer 18

Lymph nodes, spleen
Potential sites for contact with foreign antigens

Question 19

What Influences Immune Responses?

Answer 19

Individual: age (middle age is best), overall health, genetic capacity
Immunogen dose: too small = no response, too much = specific unresponsiveness
Route of entry: oral, subcutaneous, intramuscular, intravenous, respiratory, genitourinary
Genetic predisposition: linked to major histocompatibility complex and receptors generated during T/B cell development

Initial response mounted in spleen or lymph nodes

Question 20

Major Histocompatibility Complex (MHC)

Answer 20

System of genes that code the molecules on the cell surface used to present antigens