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40 Cards in this Set
- Front
- Back
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What are the two types of defense mechanisms of a host?
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Innate, nonspecific:
-1st Line of Defense (anatomical and physiological barriers) - 2nd Line of Defense (cellular and chemical systems) Acquired, specific, 3rd Line of Defense -Naturally acquired: -Active (Infection) -Passive (Maternal Antibodies) Artificially Acquired: -Active (Vaccination) -Passive (*gets when* Immune serum) |
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What are the two types of acquire, specific defense?
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Acquired, specific, 3rd Line of Defense:
-Naturally acquired -Active (Infection) -Passive (Maternal Antibodies) -Artificially Acquired -Active (Vaccination) -Passive (*gets when* Immune serum) |
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What are the two factors of 1st line of defense? ( Innate, nonspecific)
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First Line of Defense:
-Physical Factors -Skin -Mucous Membrane -Chemical Factors -Sebum -Gastric Acid -Lysozyme |
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What are the two layers of skin?
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Skin consists of two layers:
-epidermis –outer thinner portion made of tightly packed cells (upper layer- dead cells) -dermis – inner thicker portion provides strength to skin -infection can develop when the epithelial surface is broken |
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What are the mucous membranes?
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gastrointestinal, respiratory and genitourinary tracts
-Epithelial layer secrets the mucus that maintains the surface of the membrane always moist -Mucous membranes are more susceptible to infections than skin |
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What are the lacrimal apparatus and ciliary escalator?
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Other physical barriers
-Lacrimal apparatus -provides washing action removal of microbes -Ciliary Escalator -lower respiratory tract covered with cilia; propel mucus containing microorganisms upward |
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What are the chemical factors of the 1st line of defense?
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-Sebum –oily substance produced by skin; contain unsaturated fatty acids - inhibit the growth of certain pathogenic bacteria
-Gastric juice: mixture of hydrochloric acid, enzymes, and mucus; kills most of bacteria except Clostridium botulium and Staphylococcus aureus - Lysozyme in saliva and tears : enzyme that hydrolyzes the peptoglycan |
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What is the immune system responsible for?
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Immune system is responsible for:
-Surveillance of the body – white blood cells *like soldiers that circulate around our body looking for invaders* -They*(white blood cells)* recognize foreign material – distinguish between “self” and “nonself” -Destruction of foreign entities |
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What are the body systems involved in immune defenses?
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-Reticuloendothelial system
-Extracellular fluid -Bloodstream -Lymphatic system |
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What is the reticuloendothelian system?
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Reticuloendothelial System
Consists of: -Pathogenic cells located in reticular connective tissue -*reticular connective tissue is a* Network of connective tissue fibers that surround all organs -Interconnects neighboring cells -Provides a passageway between tissues and organs |
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What is blood?
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Blood
- A liquid connective tissues, consists of plasma and blood cells -Plasma is a fluid containing: water (92%); proteins (antibodies); fibrinogen, hormones, nutrients, O₂ and CO₂ |
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What are the 3 types of blood cells?
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-Erythrocytes – red blood cells
-Leukocytes – white blood cells -Thrombocytes – platelets |
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Describe the functions of the 3 types of blood cells.
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Erythrocytes – carry oxygen and carbon dioxide in the blood
-Platelets –involved in blood clotting -Leukocytes – involved in defending the body against invaders |
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What are the two groups of leukocytes blood cells?
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-Granulocytes
-Agranulocytes |
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Describe granulocytes.
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-Contain large granules in the cytoplasm that have different colors based on the dye used
-3 types -Basophils – stain blue with the basic dye methylene blue -Eosinophils- stain red/orange with the acidic dye eosin -Neutrophils – stain lilac with a mixture of acidic and basic dyes -Neutrophils and eosinphils can phagocytize pathogens |
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What are the functions of the three types of granulocytes blood cells?
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-Basophils – release histamine – allergic response
-Eosinophils – produce toxic problems against helminthes (worms) -Neutrophils – highly phagocytic, can leave the blood |
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Describe agrunolocytes blood cells.
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Agranulocytes
-Cytoplasm appears uniform under a light microscope 2 types: -monocytes – leave the blood and mature into macrophages -lymphocytes – most involved in specific immunity -B lymphocytes -T lymphocytes |
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What are the two types of agrunolocytes blood cells?
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2 types:
-monocytes – leave the blood and mature into macrophages -lymphocytes – most involved in specific immunity -B lymphocytes -T lymphocytes |
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Describe monocytes (where they are formed and what are their functions)
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Monocytes
-Produced in bone marrow – discharged into the bloodstream and transformed into macrophages -Macrophages are responsible for: -Phagocytosis -Processing foreign molecules – presenting them to lymphocytes -Secreting compounds involved in immune response |
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What is the lymphatic system?
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-Consists of lymphatic fluid, vessels, and organs
-Lymphatic fluid is plasma that moved out of the blood vessels and circulates in the space between the tissue cells -Lymphatic vessels collect the lymph and returns it to the circulatory system |
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What are the lymphoid organs?
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Lymph nodes:
-Aggregated in armpit, groin, and neck area -Filters Lymph Spleen: -Abdominal cavity -Filters blood – worn-out erythrocytes Thymus: -Pharyngeal region -T-cell maturation |
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What is the second line of defense?
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Inflammation.
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Describe what inflammation is and it's three stages.
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Inflammation is a body’s response to microbial infection
-Three stages of inflammation: -Vasodilation -Edema and pus formation -Tissue repair |
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WHat happens during Vasodilation?
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Vasodilation and increased permeability of blood vessels
-An increase of diameter of blood vessel – enables increase blood flow to the damaged area -Caused by the chemicals released from damaged tissue -Histamin – vasodilation -Chemical mediators – increase permeability of blood vessels |
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What is edema?
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Edema
-Accumulation of fluid in the tissue -White blood cells (phagocytes) migrate from the blood vessels – diapedesis –they squeeze themselves between the endothelial cells -Chemotactic migration towards the site of injury -Phagocytosis occurs – formation of pus (cellular debris, bacteria) |
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What is fever?
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Fever -Abnormally elevated body temperature in response to an infection
-Body thermostat (hypothalamus) normally set at 37C -Substances called Pyrogens can reset the body thermostat to higher setting -Pyrogens -Exogenous – products of infectious agents -Endogenous (liberated from white blood cells) |
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What are the benefits of fever?
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Benefits of fever
-Inhibits the growth of temperature sensitive microorganisms -Increased production of transferins (decreased availability of iron) -Faster tissue repair |
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WHat complications can come with a fever?
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Complications of Fever:
-Tachycardia -Dehydration -Electrolyte imbalance -Coma |
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What is phagocytosis?
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Phagocytosis (eat, cell)
-Certain types of white blood cells eliminate the microbes that entered the body by phagocytosis -The most important phagocytic cells are macrophages -Macrophages either reside in a specific organ or they wander throughout the tissues |
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What are the five phases of phagocytosis?
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1-Chemotaxis
-2Ingestion -3formation of phagolysosomes 4-Digestion 5-Excretion |
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What happens during chemotaxis?
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Chemotaxis – Phagocytes are attracted by:
-microbial products -damaged tissue cells -The plasma membrane of the phagocyte attaches to the microbe and identifies it as “nonself” |
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What happens during Ingestion in phagocytosis.
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-Ingestion :
-a phagocyte extends the pseudopds that engulf the microbe -inside the phagocyte, the microbe is located within a sac called phagosome |
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What happens during formation of phagolysosomes?
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-Formation of phagolysosomes
-Phagosome fuses with lysosome forming a single structure – phagolysosome |
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What happens during digestion in phagocytosis?
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Digestion
-Bacteria are killed by reactive oxygen species (H₂O₂, singlet oxygen) and lysozyme |
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what happens during excretion during phagocytosis?
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-Excretion
-Bacteria are digested. The waste products discharged outside the cell. |
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How to microbes evade phagocytosis?
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Microbial Evasion of Phagocytosis
-Some microbes resist the attachment of phagocyte by producing large capsules -Microbial toxins can kill a phagocyte -Microbial enzyme can lyse phagolysosome -Some microbes enter the phagocyte – they either multiply or remain dormant |
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What antimicrobial substances does the body produce?
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-The body produces antimicrobial substances:
-Interferon: -Interferon alpha and beta (produced by lymphocytes, macrophages, fibroblasts) -Interferon gamma (produced by T-cells) -The complement system: -The serum proteins that contribute to destruction of microbes |
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What are interferons?
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Interferons
-Proteins that interfere with viral multiplication. -Virus-infected cell produces and releases the interferon that enters now the neighboring non-infected cell -This triggers the cell to produce antiviral proteins (AVP) -Other effects: -Defense against other, non-viral microbes -Play role in maturation B and T lymphocytes -Inhibits cancer cells |
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what are complement proteins?
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Complement Proteins
-The complement system consists of about 30 proteins found in the serum -Designated by the letter “C” -Act in a cascade (one reaction triggers another) -Complement activation occurs in 3 pathways -Classical -Lectin -Alternative |
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what are the steps in classical complement pathway?
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-Initiation :
-C1 component binds to antibodies bound to a pathogen -Amplification: -C1 activates other components -Polymerization: -The components aggregate and integrate into pathogen membrane -Membrane attack: -The final product is an enzyme that punctures pores in the membrane |
