Mod 2 Flashcards
How does normal flora protect us?
By taking up space so pathogens are less able to adhere to the surface
Internal surfaces of the body are sterile. (T/F)
True
What are the internal surfaces that are sterile?
Tissues, blood, cerebrospinal fluid, peritoneal pericardial and other fluids
What Is considered normal flora?
Microorganisms that are permanent residences and don’t produce disease under normal circumstances
What part of the body has the greatest normal flor ppn?
The large intestine
What are the two factors that can alter normal flora?
1) excess moisture on skin
2) antibiotic use
What is the definition of contamination?
When the microorganisms are introduced to an area where they’re not expected
**there’s no growth
What is colonization?
Contamination and growth but there’s no damage to the host
Infection and disease means?
Colonization that causes damage
What’s the key difference between infection and disease?
Disease is when the host is infected and host injury is evident
Infection is the invasion but no sign of host injury
What is a pathogen?
A disease causing organism
What is virulence?
The degree of pathogenicity
What are some virulence factors?
- capsules, slimy coatings (prevents phagocytic wbc)
- substances that destroy wbc and rbc
- enzymes that dissolve tissue cement, collagen and fibrin clots
What are low-grade pathogens?
They are opportunistic; typically non-pathogenic but may cause disease when hosts defences are lowered
What are toxins?
Substances that cause damage to far-removed sites from the initial infection
What are the two types of toxins?
Exotoxins and endotoxins
What are the characteristics of exotoxins?
- mainly produced by gran positive bacteria
- released from intact bacterial cells
- carried from infection by blood
- attack a specific target tissue
What are the characteristics of endotoxins?
- produced by gram negative bacteria
- located in the cell wall therefore released when bacterial cells are disrupted
- generalize attack
- maybe responsible for fever, general malaise/aches (can have life threatening effects
- use of antibiotics can cause complications (this is due to the bacterial cell being destroyed therefore suddenly releasing endotoxins = shock)
What are the three elements that are required for transmission of infections?
- Reservoirs
- Means of transmission for microbes
- Susceptible host
What are the three kinds of reservoirs?
Humans, animals and non living things
What are non living reservoirs called?
Fomite
What is the definition of carrier?
It is a person that has the pathogenic organism but don’t have signs of infextion
What is zoonoses?
Diseases that are primarily found in animals but can be transmitted to humans
What are convalescent carriers?
Those who recovered from the disease but are carrying infectious organisms still
What is a chronic carrier?
Those still carrying the infectious organism SIX months later
What are the three principle routes of transmission?
- Contact
- Vehicle
- Vector
What is a vehicle?
Agents such as food, water, air, blood/medication
What are droplet nuclei?
Tiny particles that contain microorganism and remain in the air for a long period and float great distances
What are some ways microbes gain entry to the body?
Skin, mucous membranes, placenta and parenteral route
What is parenteral route?
Route that bypasses the gastrointestinal tract
What is the medical term for fever?
Pyrexia
What is considered a fever?
+1c above normal body tempt
What is normal body temperature?
36.1c—37.8c
What usually causes the core of the body to heat up?
- constriction of the blood vessels
- increased metabolic rate
- shivering
What causes the lymph nodes to swell?
- Microbes from tissues getting trapped in the nodes and then multiplying
- lymphocyte multiplication
1 swollen lymph node = ?
Infected node
Many swollen nodes = ?
Immune system is responding to microbes
What are the 3 lymph node location close to the skin?
Cervical
Axillary (under the arm)
Inguinal
What causes inflammation?
The release of histamines
What are the 4 cardinal signs/symptoms of inflammation?
HRPS
Heat, redness, pain, swelling
What does histamine do?
- causes vasodilation — increase blood flow to the site = heat and redness
- increased permeability of blood vessels — fluid leaking from vessels to tissue = swelling and pain
How does the body clear infecting microorganisms?
- increased phagocytic wbc to the area
- antigens presented to lymphocytes to activate antibody production
- antibodies coat the bacteria so they bacteria could undergo phagocytosis
- clotting elements move to injury site to surround and isolate the microbes
What are purulent exudates?
Pus
What is pus?
Phagocytic wbc that are killed in action
What is leukocytosis?
Increase number of wbc in response to the body’s need for the cells
What is acute disease?
Disease which symptoms develop fast and runs its course quickly
What is chronic disease?
Disease where symptoms develop slowly and disease is slow to disappear
What is latent disease?
Diseases where there is a period of inactivity before symptoms appear or between attacks
What are localized infections?
Those that are confined to one area of the body
What are focal infections?
Infection confined to a specific area but pathogens/toxins can migrate to other areas
What are systemic infections?
Infections where its pathogen spreads to multiple organs/tissues (via blood, lymph)
What is disseminated infection?
The same as systemic infections
What does septicaemia mean?
Presence and multiplication of pathogens in the blood
What does bacteraemia mean?
Presence but not multiplication of bacteria in the blood therefore = in transit
What does viremia mean?
Presence but not multiplication of viruses in the blood = in transit
What is toxaemia?
Presence of toxins in blood
What’s the difference between exogenous and endogenous infections?
- exo = outside the body microbes causing infection
- endo = within the body microbes causing infection
What’s the difference between primary and secondary infection?
Primary = infection in someone previously healthy Secondary = infection, caused by another microorganism, that immediately follows a primary infection
What are nosocomial infections?
Infections that are acquired during a stay at a hospital or health care facility (HAI)
What are factors that contribute to nosocomial infections?
- hospital microorganisms
- immunodeficit/immunocompromised individuals
- transmission
What are most common nosocomial infections?
- UTIs
- surgical wound infections
- pneumonia
What are antibiotics?
- substance that inhibits the growth/kills bacteria
- made from other microorganisms such as fungus
What’s the difference between narrow spectrum and broad spectrum antibiotics?
Narrow = effective against a small group of bacteria
Broad = effective against a large group of bacteria
What is antibiotic susceptibility/sensitivity testing?
To test what antibiotics effects the bacteria in question
How is antibiotic sensitivity tested?
Evenly spreading bacteria on a plate, putting paper soaked in difference antibiotics on the plate, seeing where the growth is inhibited
What are super bugs?
Drug-resistant bacteria
What are some examples of super bugs?
- methicillin-resistant Staphylococcus aureus (MRSA)
- vancomycin-resistant Enterococcus (VRE)
- Clostridium difficile
What is epidemiology?
Study of incidence, sources and spread of disease
What is an epidemiologist?
Those who track and contain outbreaks of infections
