Non-Specific Lines Of Defense

Front 1

Characteristics of Non-specific immune response

Back 1

Definition: Same immune response against any type of pathogen.
Response Time: Fast, inflammation develops quickly

Memory of previous exposure: None

Front 2

What are the components of first line of defense

Back 2

1. Skin
2. Mucous membranes
3. secretions
4. Normal Microbiota

Front 3

What are protective factor of skin?

Back 3

1.Sebum/oil (lysozyme) rich in fatty acid  acidic pH on skin
2.Keratinized epidermis keeps skin dry
3.Closely pack cells
4. Periodic shedding of skin cells
5.Sweat- high salt concentration
6.Lysozyme present in sweat (damages peptidoglycan) and hurts GM+ bacteria

Front 4

What are protective factors of mucous membrane?

Back 4

In Conjunctiva of eye: tears (rich in salt and lysozyme) tears flush out eyes

In respiratory tracts: Mucous: Ciliary living (ciliary escalator)

In GI tract: Acidic pH (gastric juice) Movement of food (peristalsis) through tract

In genitourinary tract: Urine- Flushes the urinary tract Vaginal pH and normal flora is acidic (prevents pathogen growth) 

Front 5

What are the components of second line of defense?

Back 5

1.Complement System
2. Inflammation
3. Phagocytosis
4. Fever
5.Antimicrobial compounds:
Interferons
Transferrin
Antimicrobial peptides

Front 6

Blood cells and their functions.

Back 6

RBC (Erythrocytes) Transport gases

WBC- Leukocytes (defense)

Platelets- Thrombocytes (blood clotting)

Front 7

What are typical signs and symptoms associated with an inflammatory response?

Back 7

Pain, localized heat, redness, swelling

Front 8

What are the order if events that occur during an inflammatory response?

Back 8

1. Tissue Damage:
2. Release of acute phase proteins: Ex- histamines, prostaglandins, leukotrienes
3. Vasodilation:What happens during vasodilation? Increase in diameter of blood vessel, more blood supply  supplies more nutrients WBC’s (phagocyte) more O2, clotting factors Examples of vasodilators? histamine, protaglandins
4. Phagocytic migration : Movement of phagocytes (chemotaxis) in response to chemotactic factors (ex- C3a, C5a, complement component, leukotrienes)
5. Phagocytic margination: Attachment of phagocyte to inner lining of blood vessels (endothelium)
6. Pahgocytic emigration: (diapedesis) phagocytes are released (squeezed out) between gaps of endothelial cells because of increased vascular permeability (protaglandin increases vascular permeability)
7. Phagocytosis:
8. Tissue repair: More nutrients and O2

Front 9

What happens during vasodilation?

Back 9

Increase in diameter of blood vessel, more blood supply --> supplies more nutrients WBC’s (phagocyte) more O2, clotting factors Examples of vasodilators? histamine, protaglandins

Front 10

What happens during margination?

Back 10

Attachment of phagocyte to inner lining of blood vessels (endothelium)

Front 11

What happens during phagocytic migration.

Back 11

Movement of phagocytes (chemotaxis) in response to chemotactic factors (ex- C3a, C5a, complement component, leukotrienes)

Front 12

What happens during emigration?

Back 12

(diapedesis) phagocytes are released (squeezed out) between gaps of endothelial cells because of increased vascular permeability (protaglandin increases vascular permeability)

Front 13

What WBCs are phagocytic in nature?

Back 13

monocytes (macrophages), neutrophils (initial stages)

Front 14

Examples of fixed macrophages in the body.

Back 14

monocytes- microglia cells and kupffer cells

Front 15

The order of events that occur during phagocytosis.

Back 15

1. Chemotaxis towards a pathogen
2. adherence: Attachment of phagocyte to pathogen (opsonization of a pathogen enhances adherence event) opsonin- C3b, antibodies
3. Ingestion: by formation vesicle (by pseudopods of phagocyte) and after ingestion called phagosome
4. Digestion: In phagolysosome. – Phagocyte fuses with lysosome (have digestion enzymes; protease, nuclease, lipase) along with toxic forms of oxygen (ex. Superoxide free radical, peroxide ion) Phagolysosome bacteria is digested
5. Formation of residual body: Phagolysome containing undigested components of pathogen
6. discharge of waste material

Front 16

What is opsonization?

Back 16

Attachment of phagocyte to pathogen (opsonization of a pathogen enhances adherence event) opsonin- C3b, antibodies

Front 17

Ingestion (what structure in WBC does mediate this process in WBC)?

Back 17

phagosome

Front 18

How a bacterial cell is digested inside a phagocyte?

Back 18

Phagocyte fuses with lysosome (have digestion enzymes; protease, nuclease, lipase) along with toxic forms of oxygen

Front 19

What is a phagolysosome?

Back 19

residual body containing undigested components of pathogen

Front 20

What is complement system?

Back 20

Consists of a group of proteins called complement components. (C1-C9) P, B, D One component then triggers another. Present in inactive form in blood serum (no pathogen present)
When activated splits into two subcomponents which are active. (Ex- C3 C3a, C3a)

Front 21

What are three results of complement activation?

Back 21

1. Opsonization: Coat the pathogen, help the phagocyte recognize and ingest pathogen easily

2. Inflammation (and chemotaxis): By release of histamine from some cells (mast cells, ect.)

3. Cytolysis: By formation of MAC in plasma membrane of bacteria. Destroys the pathogen (forms holes in pathogens membrane) c5b+c6+c7+c8+c9 all bind together and form an attacking complex which forms holes in invading pathogens cytoplasmic membrane.

Front 22

What activated complement components mediate opsonozation, infammation and cytolysis, what components are chemotactic factors?

Back 22

C3a- Activates C5 C5a and C5b C5a and C3a act as chemotatic factors (attracts phagocytes) , also initiate inflammation ; Mast cells have receptors for c3a, c5a which activate mast cell to release histamine (vasodilator)

Front 23

What are interferons (characteristics)

Back 23

Proteins produced in response to viral infection

Front 24

How are they able to prevent spread of viral infection in the host?

Back 24

Infected cell secretes infereron that bind to receptor on neighboring, uninfected cell.
Uninfected cell is stimulated to produce anti-viral protines (AVP’s)
AVP’s degrade viral RNA and inhibit protein synthesis

Front 25

Transferrin:

Back 25

Transferrin: These are iron binding proteins in the blood reduces availability of free iron for pathogen

Front 26

Defensins

Back 26

Antimicrobial peptides: ex- Defensins 40 amino acids long
Antimicrobial peptides with broad spectrum of activity.
inhibit metabolism, forms holes in the membrane of pathogen

Front 27

Effects of fever?

Back 27

Enhances immune response; helps inhibit growth of bacteria (denatures enzymes)

Front 28

Classical Pathway:

Back 28

Mediated by antibodies against protein or polysaccharide antigen (2 sites, antigen binding site; part of cell surface against which antibodies are produced)

Front 29

Alternative Pathway:

Back 29

Mediated by factor B, P (properdin), D , able to recognize LPS (lipopolysaccharide) antigens

Front 30

Lectin Pathway:

Back 30

Carbohydrate binding proteins that bind to carbohydrate antigen of a pathogen.
All three pathways are activating C3 component of complement system