1.
2 Pathways of the compliment system: Classical Pathway, activated by antibody binding to antigen
Alternative Pathway, activated by contact between complement proteins and polysaccharides on pathogen
2.
Adaptive immune response: Body makes antibody in response to antigen (after 1st exposure). Need 1st exposure the 2nd exposure you have the antibodies
3.
Agranulocytes: Type of leukocyte. Lack granular cytoplasm with round nuclei.
Includes:
Monocytes
Lymphocyte
4.
Basophils: Release histamine, which helps initiate inflammatory response
5.
Cellular defenses: Blood consists of about 60% liquid called plasma and 40% formed elements.
Formed elements: Erythrocytes (RBC), platelets (blood clotting), and leukocytes (WBC).
Leukocytes are defensive cells important in adaptive and innate host defenses
6.
Chemical barriers: Sweat glands - high salt conc
Sweat and Sebum - low pH, acidic
Stomach - low pH, acidic
Tears, Saliza, Mucous - lysozyme, degrades peptidoglycan in gram positive
Blood - contains transferrin to bind iron (bac need the iron but can't get to it
Saliva, Mucous, Milk - lactoferrin binds iron
Defensins - group of molecules that can kill pathogens by forming pores in membrane
7.
Chronic Inflammation: Neither the agent of inflammation nor the host wins - agent and body are fighting neither win nor give up.
Inflammation continues to produce tissue damage.
Because the cause is not destroyed, the host attempts to limit or confine the agent.
Can lead to granulomatous inflammation, a wall of inflammation surrounding the pathogen
8.
Cytokines: Body produces these to direct phagocyte to pathogen. -toll like receptors on the phagocytic cell is what recognizes the pathogen
9.
Dendritic cells: Phagocytic cells that resemble nerve cells
10.
Eosinophils: Secrete toxins to kill worms and other large parasites
11.
Eosinophils: Present in large numbers during allergic reactions
12.
Evasion of phagocytosis - Adherence and ingestion: Adherence and Ingestion: Antiphagocytic capsule will not allow phagocyte to adhere and ingest. OR M protein in cell wall of Streptococcus pyogenes prevents the adherence so the ohagocyte can't bind and ingest
13.
Evasion of phagocytosis - chemotaxis: Chemotaxis: some bacteria such as invasive strains of Nesseria gonorrhoeae do not release chemical attractants (they won't direct the phagocytes toward them)
14.
Evasion of phagocytosis - Digestion: -Capsules that are not vulnerable to lysozomal digestion (Yersinia pestis) These capsules cannot be digested.
-Resist lysozomal enzymes (Mycobacterium and Leishmania species - acid fast cell is resistant, these will actually replicate inside the phagocyte.
-Microbial toxins force phagocytes to release their lysozomal enzymes into their own cytoplasm (instead of keeping them compartmentalized) 2 toxins are Leukocidin or Streptolysin
*all of these are virulence factors
15.
Extracellular killing: Outside of cell, killing of microbes without phagocytosis.
Eosinophils
Natural Killer Cells
16.
Fever: Systemic increase in body temperature to oral temperatures above 37.8C or 100.5F.
Caused by pyrogens:
-Endotoxins and exotoxins from microbes
-Endogenous pyrogen from macrophages - found in body
17.
Granulocytes: (type of leukocyte) Characterized by granular cytoplasm and an irregularly shaped, lobed nucleus
Includes:
-Basophil
-Mast cell
-Eosinophils
-Neutrophils
-Dendritic cells
*derived from myeloid stem cells in bone marrow
18.
Granulomatous Inflammation: Results in granulomas, tissue that surrounds and walls off the inflammatory agent.
Granulomas associated with disease
-Gummas - syphillis
-Lepromas - Leprosy, (Hansen's disease)
-Tubercules - tuberculosis
Anti-inflammatory drugs can release the organism from the granulomas, may not be a good thing
19.
How is a fever beneficial: -Slows growth of bac
-inactivates microbial toxins and enzymes
-Heighten level of immune system by speeding up reactions - good!
-Makes patient feel ill, telling you to rest
20.
Inflammation: The body's defensive response to tissue damage from microbial infection
-Temo
-Redness
-Swelling
-Pain
21.
Innate immune response: Used to be called nonspecific, but it's not really true. It does not require a previous exposure to be active.
22.
Lymphocytes: derived from lymphoid stem cells and contribute to adaptive host immunity, phagocytic.
Lymphocytes circulate in blood and are found in lymph nodes, spleen, thymus, tonsils
23.
Macrophages: "Big eaters" that destroy not only microorganisms but also larger particles. 1st attack at portals of entry. Can survive for months
*When monocytes migrate from bone marrow to blood then finally tissue they go through changes and mature into macrophages
24.
Mast Cells: prevalent in connective tissue, release histamine, associated with allergies
25.
Molecular defenses - compliment: Refers to a set of more than 20 large regulatory proteins that play a key role in host defense.
Works as a cascade: a set of reactions that amplify some effect - dominoe effect
General functions include:
1. Enhance phagocytosis - make org tasty [Opsonization]
2. Lyse pathogens directly - poke holes in mem [Membrane attack complexes]
3. Generate peptide fragments that regulate (turn on/off) inflammation and immune responses [Inflammation]
26.
Molecular defenses - interferon: Interferes with viral replication on other cells
-Humans have three groups of interferon (alpha, Beta, gamma)
-Stimulates cell to make antiviral enzymes (infected cells stimulate noninfected cells to produce these antiviral enzymes by releasing interferons
Virus infects the cell, cell infected with virus turns on gene for interferon and now cell makes interferon. Interceron released to neighbor cell and signals nucleus to turn on the gene for antiviral protein. Any cell with antiviral protein can have penetration but no replication.
!st infected cell can still replicate but those warned with interferon cannot! *Abortive viral infection
27.
Monocytes: Phagocytic cells derived from myeloid stem cells
28.
Natural Killer Cells (NK cells): secrete cytotoxic proteins which kill cells infected with viruses - kills abnormal cells
29.
Neutrophils: (polymorphonuclear leukocytes) Phagocytic cells that guard skin/mucous membranes against infections. Usually 1st on scene, respond quickly to tissue injusry. Usually only alive for a couple days
30.
Phagocytes: Cells that literally eat or engulf materials. Patrol or circulate through the body destroying dead cells and cellular debris. Guard the skin/mucous mem against invasion by microorganisms
31.
Phagocytosis: Chemotaxis: recognize and move toward invading organisms and cytokines (actual mvmt of cells)
Adherence and Ingestion: bind certain molecules on microbe and engulf microbe
Digestion: phagolysozome contains digestive enzymes
32.
Physical Barriers: Composed of skin and mucous membranes. These line the body and secrete chemicals to make surfaces hard to penetrate and inhospitable to live on
Also includes mechanical barriers. Hairs, Mucous, Coughing, Sneezing, vomitting, urinating...all are meant to remove things from the body)
33.
The lymphatic system: Peyers Patches - Lymphoid nodules found in the ileum of the small intestine - filled with lymphocytes
GALT - Gut associated lymphatic tissue, ALL tissue of the lymphoid nodules, Major site of antibody production against mucosal pathogens
34.
What are some fixed macrophages and where are they found: Alveolar Macrophage - lung
Histiocyte - connective tissue
Kupffer cell - liver
Microglial cell - neural tissue
Osteoclast - Bone
Sinusoidal lining cell - spleen
35.
What are some innate defenses?: -Physical Barriers: Skin, mucous membranes
-Chemical Barriers: Substances in fluid, saliva mucous, gastrointestinal juice
-Cellular defenses: Cells that phagocytize (engulf) microorganisms
-Inflammation: Swelling, redness,heat
-Fever: Body temperature increases
-Molecular defenses: Interferon, compliment
36.
What are the steps in Inflammation: 1. Cut allows bac to get beneath surface of skin
2. Damaged cells release histamine and bradykinin
3. Capillaries dilate (vasodilation), bringing more blood to the tissue. Skin becomes reddened and warmer
4. Capillaries become more permeable, allowing fluids to accumulate and cause swelling (edema)
5. Blood clotting occurs and scab forms
6. Bacteria multiply in cut
7. Phagocytes enter tissue by moving through the walls of the blood vessels (diapedesis)
8. Phagocytic cells are attracted to bacteria and tissue debria (chemotaxis) and engulf them
9. Larger blood vessels dilate, further increasing blood supply to tissue and adding to heat and redness
10 As dead cells and debris are removed, epithelial cells prliferate and begin to grow under the scab
11. Scar tissue (connective tissue) replaces cells that cannot replace themselves
37.
What are the three main functions of the compliment system: Opsonization
Membrane attack complexes
Inflammation
38.
What are the two types of macrophages: Wandering: circulate throughout the body
Fixed: Remain stationary in tissue
