Immunology (Slide Set 6)

Question 1

What is the first line of defense?

Answer 1

Innate
Any barrier that blocks invasion at the portal of entry (physical barriers -> skin)

Question 2

What is the second line of defense?

Answer 2

Innate
Protective cells and fluids which include inflammation, phagocytosis, and fever soluble mediators

Question 3

What is the third line of defense

Answer 3

Acquired
Adaptive and acquired on an individual basis as each foreign substance is encountered by white blood cells called lymphocytes (Ex: B & T cells, antibodies)

Question 4

What physical and chemical barriers act as the first line of defense?

Answer 4

Skin
Sebaceous secretions
Dermicidein (secreted by skin cells, break down bacterial membranes)
Mucous membranes
Eyes/tears
Saliva
Runny nose
Urine
Intestine’s digestive jucies
Cough
Semen
Vagina
Ciliary defenses
Genetics

Question 5

How does skin act as a physical barrier from microbes?

Answer 5

Dead skin cells on the surface of the epidermis are continually shed, taking with them microbes on the skin’s surface

Question 6

How does genetic resistance to infections work?

Answer 6

Microbes are species specific. Humans may be immune to many diseases that affect other mammals.

Viruses gain entry to cells by binding to specific receptors that may vary enough between species. Thus, a virus that binds to receptor A in a dog cannot bind to the same receptor in human because the two receptors from different species vary in sequences and shape. Spike proteins are specific to species.

Question 7

What are the 3 functions of the immune system?

Answer 7

1. Surveillance for foreign material/microbes
2. Recognition of foreign material/microbes
3. Attack and destroy foreign microbes

Question 8

How does the second line of defense of the immune system work?

Answer 8

WBC involve the innate capacity to recognize foreign material including pathogens. Recognizes self from foreign by recognizing molecular markers called PATHOGEN-ASSOCIATED MOLECULAR PATTERNS (PAMPs) on microbes by using PATTERN RECOGNITION RECEPTORS (PRR) on immune cells

Microbes have PAMPs
WBC have PRRs
PRRs find PAMPs

Question 9

What are some examples of PAMPs?

Answer 9

Ex of bacterial PAMPs: flagellin, peptidoglycan, lipopolysaccharides

Ex of viral PAMPs: double stranded RNA

Question 10

What are cytokines?

Answer 10

Cytokines are molecular messages.
They are either autocrine, paracrine, or endocrine

Autocrine: same cell secretes and receives cytokine signal
Paracrine: cytokine signal secreted to a nearby cell
Endocrine: cytokine signal secreted to circulatory system and travels to distant cells

Question 11

Slide 10

Question 12

Mast cells

Answer 12

trigger local inflammatory reactions (histamines) including allergic symptoms
innate immunity

Question 13

Neutrophils

Answer 13

phagocytosis of microbes
innate immunity

Question 14

Basophiles

Answer 14

inflammation and allergic events
innate immunity

Question 15

Eosinophils

Answer 15

active against worm and fungal infections
innate immunity

Question 16

Lymphocytes

Answer 16

involved in specific immune function
adaptive

a) natural killer cells: active against virus infected cells and cancerous cells

b) B and T cells: B cells produce antibodies and T cells kill foreign cells

Question 17

Monocytes

Answer 17

a) macrophages: ingest and kill foreign cells
b) dendritic cells: responsible for processing foreign matter and presenting it to lymphocytes

Question 18

Describe the functions of B and T cells

Answer 18

B cells contribute to humoral immunity. Once a B cell becomes “activated” they become plasma cells and start to produce antibodies

T cells contribute to cell mediated immunity by killing foreign cells

Both classes of immune cells are responsible for immunologic “memory”

Question 19

What are the functions of the lymphatic system?

Question 20

What constituents make up the lymphatic system?

Answer 20

Fluid:
Lymphatic Vessels:

Question 21

What are the differences between blood stream and lymphatics?

Question 22

How does the lymphatic system aid the immune system?

Question 23

What organs make up the lymphatic systems?

Question 24

What are the stages of inflammation?

Question 25

How do white blood cells get attracted to the site of infection?

Question 26

What causes a fever?

Question 27

What are pyrogens? What are the different types?

Question 28

What are the benefits of a fever?

Question 29

How does phagocytosis work?