Module 2 Flashcards
Physical and Chemical Barriers to Infection?
Skin and Mucous Membranes/Secretions
Is the inflammatory response specific or non specific?
non specific
When does the inflammatory response occur?
after tissue injury or infection
Inflammatory Response leads to …
Inflammation and Fever
The inflammatory response is a ____ and ____ protection against invasion by a _____ range of pathogens
immediate, general, wide
What parts of the immune system does the inflammatory response involve?
phagocytic WBC, antimicrobial substances, natural killer cells
Is the immune response specific or no specific?
specific
The immune response leads to …
antigen-antibody response
Self vs Non-self
- host versus foreign substance
- used in the immune response
- leads to recognition and elimination of altered host cells
The immune system develops more ___ and involves _____ cells to combat a ____ ____
slowly; specific; particular pathogen
1st Line of Nonspecific Resistance to Disease
Skin Mucous Membranes Mucus Hairs Cilia Lacrimal Apparatus Saliva Urine Defecation and Vomiting Acid pH of Skin Unsaturated Fatty Acids Lysozyme Gastric Juice Vaginal Secretions (these are Mechanical and Chemical Factors)
2nd Line of Nonspecific Resistance to Disease
Antimicrobial Proteins: Interferons and Complement System Natural Killer Cells Phagocytes Inflammation Fever
Interferons are glycoproteins with _____ activity
anti viral
Important Structures of the Immune System
- Lymph Nodes
- Thymus
- Spleen
- Tonsils
- Red Bone Marrow
How do lymph nodes work in the immune system?
Distributes lymph fluid among the body to remove bacteria and toxins from circulation. Also causes proliferation of immune cells
How does the thymus work in the immune system?
- located in the mediastinum
- produces T lymphocytes
How does the spleen work in the immune system?
- largest lymph organ
- reservoir for blood
- macrophages clear cellular debris and process hemoglobin
How does the tonsils work in the immune system?
- produces lymphocytes
- guard against airborne and ingested pathogens
How does the red bone marrow work in the immune system?
houses stem cells that develop into lymphocytes
Primary Lymphatic Organs
- organs providing the environment for stem cells to divide and mature
- crucial to the inflammatory responses maintenance
- Red Bone Marrow and Thymus Gland
Secondary Lymphatic Organs
- sites where most immune responses occur
- Lymph nodes and nodules, and the spleen
Lymphatic Flow
- lymph flow is similar to blood with a lower protein count and no RBC
- its made in tissue spaces and then gathered in small vessels to carry it to the thoracic or right lymphatic duct
What does lymph flow allow for?
the removal of things to large to cross the capillary membrane
Right Lymphatic Duct
drains the right side of the thorax, head, and neck (1/4 of the person)
Thoracic Duct
drains the lymph for all parts of the body except for the upper right fourth
Pathogen
Disease Agent
Microbial factors to be aware of?
Virulence
Dose
Portal of Entry
Organ Preference
Virulence
refers to how sick a pathogen can make you
What 3 Things does Response to Disease Rely on?
Pathogen (microbial factors, microbes)
Host (resistance, susceptibility, host factors)
Environment (conditions)
Epidemiologic Triangle
Triad of things leading to the disease response: Agent(infectious factor), Host(intrinsic), and Environment(extrinsic)
Agent
originally referred to as infectious microorganism until it became more broad
Biologic Agents
Allergens and infectious organisms
Chemical Agents
toxins and dust
Physical Agents
kinetic energy, radiation, thermal energy, noise
Are social and psychological stressors agents of disease?
yes
Infection
-Host organism’s response to a pathogen caused by tissue destroying microorganisms entering and multiplying in the body
-emia means?
“in the blood”
Sepsis
infection; contamination
Bacteremia
presence of bacteria in the blood
Viremia
presence of virus particles in the blood
Septicemia
systemic infection in which pathogens are present in the blood having spread from an infection in any part of the body
Do Bacteremia and Viremia always become Septicemia?
no, competent immune systems can keep the infection localized
Viruses
- cause infection
- microscopic genetic obligate intracellular parasites
- protein coat + nucleic acid core + DNA or RNA
- no Metabolic capability, need host cell
- some can reproduce outside a living cell
- can be dormant for long periods of times and produce symptoms years or months after infections
When do viruses activate?
in times of increased stress
Bacteria
-single celled microorganisms with no true nucleus
-larger than viruses
reproduce by cellular division
-contain cell damaging proteins
Endotoxins
released when the bacterial cell wall decomposes; can cause fever and are not affected by antibiotics
Exotoxins
released during cell growth from bacteria
How are bacteria classified?
- Shape
- growth requirements
- motility
- oxygen requirements
- gram stain
Gram Positive Stains?
purple
Gram negative stains?
it does not stain
Do gram positive or negative have more virulence?
Gram negative
Mycoplasmas
- 1/3 the size of bacteria
- can reproduce independently
- NO rigid cell wall
- can cause atypical pneumonia (especially in crowded living conditions)
Rickettsiae
- needs a host for nutrients
- uses cell division
- has a rigid cell call
- infection caused by bite of infected arthropod
Examples of Infections/Diseases caused by Rickettsiae?
Typhus
Rocky Mountain Spotted Fever
Fungi
- non photosynthetic microorganisms
- asexual cell division or sexual division
- all fungi are spore based regardless of division type
- contains a true nucleus
- relatively large
- causes mycoses
Classifications of Fungi
Yeasts
Molds
Yeast
round, single cells, facultative anaerobes (live with or without oxygen)
Molds
filament like, multi nucleated, aerobic organisms
Mycoses
infections caused by fungi that release mycotoxins
When do mycoses become severe?
when the patients immune system is compromised (opportunistic infection) or if the fungi becomes systemic
Most mycotic infections are…
mild (athlete’s foot, candidiasis)
Parasites that cause infection?
Protozoa
Helminths
Arthropods
Ectoparasites
Parasite
depend on host for food and protective environment
Protozoa
- unicellular animals
- transmitted via arthropod vector or contaminated food/water
What causes malaria or amebic dysentary?
protozoa
Helminths
- worm like parasites
- transmitted by ingestion of fertilized eggs or larva penetration of the skin
- common in developing countries
Arthropods
- jointed exoskeleton and paired jointed legs
- can serve as vectors for other diseases
Examples of Arthropods
ticks, mosquitoes, biting flies
Ectoparasites
organism that lives on the outside of the body
How are ectoparasites transmit?
contact with infected clothing, bedding, or grooming articles
examples of Ectoparasites?
mites, lice, chiggers
Normal Body Flora
harmless microorganisms that reside in or on the body
Where is normal body flora found
skin, mouth, nose, pharynx, distal intestine, colon, distal urethra, vagina
Intestinal flora help synthesize …
Vitamin K
When can normal body flora become opportunistic?q
incompetent/compromised immune systems
What are host factors?
factors responsible for the degree to which the individual is able to adapt to the stressors produced by the agent (resistance). These can be controllable or not controllable depending.
Examples of Host Factors
- Genotype/Phenotype
- Nutritional Status
- Immune System
- Social Behaviors
How does environment influence infection?
influences the probability and circumstances of contact between the host and agent
What things does environment include?
sanitation, living conditions, pollution, social/political/economic factors
Chain of Infection
a model to conceptualize the transmission of a communicable disease from its source to a susceptible host
What do we want to do with the chain of infection?
break it!
What are the six links of the chain of infection?
Pathogen - Reservoir - Portal of Exit - Transmission - Portal of Entry - New Host
Reservoir
the habitat in which an infectious agent normally lives or grows (person, animal, environment)
Zoonoses
infectious animal reservoir
Important Cellular Elements in Infection/Inflammation
Granulocytes
Agranulocytes
Red Blood Cells
Platelets
Granulocytes
- Have granules in cytoplasm
- releases histamine and heparin in the inflammatory response
1. Neutrophils and Bands
2. Basophils
3. Eosinophils
Agranulocytes
- lymphocytes
- monocytes
Hematopoiesis
formation of new cells in the bone marrow
Hematopoietic Stem Cell Differentiation
Stem cell –> Common Lymphoid Progenitor –> B-cell or T-Cell –> Plasma Cell and Activated T Cell
Stem Cell –> Myeloid Progenitor –> Megakaryocyte and Erthrythroblast –> Platelets and Erythrocytes
Stem Cell –> Myeloid progenitor –> Leukocytes - - -> Basophils become Mast cells to release histamine and Monocytes become Macrophages
How much of the blood is WBC
less than 1 percent
What do WBC do?
protect the body against harmful bacteria and infection
Pyogenic
pus eating (this is WBCs)
the 3 Granulocytes are…
neutrophils, basophils, and eosinaophils
the 2 agranulocytes are…
monocytes and lymphocytes
Neutrophils
- WBC
- they phagocytosis “pyogenic infections”
Bands
-immature neutrophils (1-3 % of neutrophils)
How much of the Neutrophils are Bands?
1 to 3 %
What is a “shift to the left”?
When mature neutrophils have died battling infection and the average/mean size of the neutrophil gets smaller due to the release of Bands to compensate and the lessening of fighting ability, the whole bell curve shape shift left. This means a more bacterial infection is occurring
What does a shift to the left indicate
a bacterial infection
Basophils
- become mast cells
- involved in allergies and inflammatory responses
- release histamine and heparin once they are mast cells
Eosinophils
- release heparin and histamine
- involved in delayed allergic reactions and parasitic infections
- Hay fever leads to decreased amount
Monocytes
become macrophages which phagocytose in severe infections - more delayed in response (2nd responders)