Innate Immunity (17)

Question 1

3 lines of defense associated with the human body

Answer 1

Physical, Chemical, and Cellular

Question 2

Types of Physical Defenses

Answer 2

Skin, Mucus Membrane, and Endothelia cells

Question 3

1. Epidermis- few pathogens can penetrate these layers, shredding of dead skin cells removes microorganisms, epidermal dendritic cells phagocytize pathogens
2. Dermis- Collogen fibers help skin resist abrasions that could introduce microorganisms
3. Chemical defenses of skin- salt inhibits growth of pathogens, lysozyme destroys cell wall of bacteria, defensins, and dermcidin’s

Answer 3

Role of Skin in Innate Immunity

Question 4

Line the mouth, nose, lungs, and urinary and digestive tracts to provide another barrier against pathogens. Epithelial cells bound by tight junctions. Epithelial cells secrete mucus, which covers and protects the more fragile layers beneath and traps debris and matter including pathogens. Mucus also contains Antimicrobial Peptides

Answer 4

Role of Mucus Membranes

Question 5

Tightly packed cells lining the urogenital tract, blood vessels, lymphatic vessels, and certain other tissues
Blood brain barrier protect the central nervous system (CNS), which consist of the brain and spinal cord

Answer 5

Role of Endothelia

Question 6

Physically remove pathogens from the body, preventing them from taking up residence. EX: Eyelid, eyelashes, tear duct, shedding of skin, excretion of feces through intestinal peristalsis

Answer 6

Mechanical Defenses

Question 7

contain the chemical mediator’s lysozyme and lactoferrin, both of which are capable of eliminating microbes that have found their way to the surface of the eyes. Lysozyme cleaves the bond between NAG and NAM in peptidoglycan, a component of the cell wall in bacteria. bacteria. Lactoferrin inhibits microbial growth by chemically binding and sequestering iron. This effectually starves many microbes that require iron for growth.

Answer 7

Role of Tears

Question 8

urine flushes microbes out of the body during urination. Furthermore, the slight acidity of urine (the average pH is about 6) inhibits the growth of many microbes and potential pathogens in the urinary tract.

Answer 8

Role of the Urinary System

Question 9

a special class of nonspecific cell-derived mediators with broad-spectrum antimicrobial properties. Some are produced routinely by the body, whereas others are primarily produced (or produced in greater quantities) in response to the presence of an invading pathogen. Defensins, Dermcidin, and Lysozyme

Answer 9

Antimicrobial Pepides

Question 10

antimicrobial peptides which are encoded by the DCD gene in human being and often secreted by sweat gland cells to provide a broad-spectrum antibacterial activity against several pathogens.

Answer 10

Dermcidin

Question 11

May be secreted or act inside the host cells; they combat microorganisms by damaging their plasma membranes

Answer 11

Defensins

Question 12

AMP, which breaks down and digests the peptidoglycan in their cell walls

Answer 12

Lysozyme

Question 13

soluble proteins that act as communication signals between cells
may be releases to stimulate production of chemical mediators or other cell functions (cell proliferation, cell differentiation, inhibition of cell division, apoptosis, and chemotaxis)

Answer 13

Cytokines

Question 14

Same cell secretes and receives cytokine signal

Answer 14

Autocrine

Question 15

Cytokine signal secreted to a nearby cell

Answer 15

Paracrine

Question 16

Cytokine signal secreted to circulatory system; travels to distant cell

Answer 16

Endocrine

Question 17

3 classes of Cytokines

Answer 17

Interleukins, Chemokines, and Interferons

Question 18

produced only by leukocytes and only stimulate leukocytes

cytokines largely produced by immune system cells that help coordinate efforts against invading pathogens

Answer 18

Interleukins

Question 19

chemotactic cytokines that recruit specific subsets of leukocytes to infections, damaged tissue, and sites of inflammation

Answer 19

Chemokines

Question 20

cytokines released by cells that have been infected with a virus; stimulate antiviral responses in nearby cells as well as the cells secreting (viral replication)

Answer 20

Interferons

Question 21

Complement System Activation (3 ways)

Answer 21

Classical pathway, Alternative pathway, and Lectin pathway

Question 22

initiated by the spontaneous activation of the complement protein C3. The hydrolysis of C3 produces two products, C3a and C3b. When no invader microbes are present, C3b is very quickly degraded in a hydrolysis reaction using the water in the blood. However, if invading microbes are present, C3b attaches to the surface of these microbes. Once attached, C3b will recruit other complement proteins in a cascade

Answer 22

Alternative pathway

Question 23

more efficient mechanism of activating the complement cascade, but it depends upon the production of antibodies by the specific adaptive immune defenses. To initiate pathway, a specific antibody must first bind to the pathogen to form an antibody-antigen complex. This activates the first protein in the complement cascade, the C1 complex. The C1 complex is a multipart protein complex, and each component participates in the full activation of the overall complex. Following recruitment and activation of the C1 complex, the remaining proteins are recruited and activated in a cascading sequence

Answer 23

Classical Pathway

Question 24

similar to the classical pathway, but it is triggered by the binding of mannose-binding lectin, an acute-phase protein, to carbohydrates on the microbial surface. Like other acute-phase proteins, lectins are produced by liver cells and are commonly upregulated in response to inflammatory signals received by the body during an infection

Answer 24

Lectin Pathway

Question 25

process of coating a pathogen with a chemical substance (an opsonin) that allows phagocytic cells to recognize, engulf, and destroy the pathogen more easily

Answer 25

Opsonization

Question 26

innate nonspecific immune response characterized by redness, swelling, heat, pain, and altered function, typically at the site of injury or infection but sometimes becoming systemic

Answer 26

Inflammation

Question 27

chemical mediators that promote the inflammatory effects of kinins and histamines. Can also help to set the body temperature higher, leading to fever, which promotes the activities of white blood cells and slightly inhibits the growth of pathogenic microbes

Answer 27

Prostaglandins

Question 28

ring structure formed from complement proteins C6 through C9 that penetrates the membranes of a targeted cell, causing cell lysis and death

Answer 28

Membrane Attack Complexes (MAC)

Question 29

Develops quickly and short lived
Dilation and increased permeability of blood vessels (diapedisis)
Migration of phagocytes
Tissue repair

Answer 29

Acute Inflammation

Question 30

Long-lasting

Damage to tissues can cause disease

Answer 30

Chronic Inflammation

Question 31

Granulocytes

Answer 31

Basophils (blue)
Eosinophils (red, cap of diapedesis, phagocytic pathogens)
Neutrophils (lilac, cap of diapedesis, phagocytize pathogens)

Question 32

Agranulocytes

Answer 32

Lymphocytes (NK)

Monocytes (leave blood and mature into macrophages, phagocytic cells that devour foreign objects)

Question 33

Mononuclear lymphocytes use nonspecific mechanism to recognize and destroy cells that are abnormal
Cancer cells and virus infected cells are targeted by these cells
Are attracted to cells that do not present MHC I, but does present ligands for the activating receptor

Answer 33

Natural Killer cells

Question 34

6 stages of Phagocytosis

Answer 34

1. Chemotaxis
2. Adherence
3. Ingestion
4. Maturation
5. Killing
6. Elimination

Question 35

Examples of Pathogen-Assocaited Molecular Patterns (PAMPs)

Answer 35

Peptidoglycan
Flagellin
Lipopolysaccharide (LPS), from outer membrane of GNB
Lipopeptides, molecule expressed by most bacteria
Nucleic Acids, viral DNA or RNA

Question 36

Small molecular motifs conserved within a class of microbes. They are recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) in both plants and animals

Answer 36

PAMPs

Question 37

pathogen recognition receptors (PRRs) that may be found on the external surface of phagocytes or facing inward in interior compartments
Bind PAMPs
Integral membrane proteins produced by phagocytic cells
-apoptosis
-secretion of inflammation mediators
-stimulate adaptive immune response

Answer 37

Toll-like receptors (TLRs)

Question 38

Final stage of inflammation
Delivers extra nutrients and oxygen to site
Some sites cannot be fully repaired and form scar tissue

Answer 38

Tissue Repair