INFC 215 Mod 2 Flashcards
What are the three things that make up the chain of infection? (R, T, H)
- Source of infection (reservoir)
- Means of transmitting the microbes
- The susceptible host
When can the chain of infection be stopped?
The chain of infection can be stopped at any time
What are the 3 reservoir for infectious microbes?
1.Humans
2. Animals
3. Non living things
What do we call a human reservoir/ person harboring pathogenic organism?
A carrier
Define zoonosis
A disease found on an animal but may be transmitted to humans
Why are carriers more dangerous than an infected person?
Carrier is more dangerous because they might not know that they are carrying dangerous micro organism
Define convalescent carrier
When a person has recovered from a disease, but are still carrying the infectious organisms
Define chronic carrier
When a person has recovered and is still carrying around the infectious organism after 6 months
What are two examples of non living reservoirs?
Water and soil
Name 2 disease caused by non living reservoirs and define what they are
- Botulism - food poisoning
- Tetanus - Spores introduced to human tissues in low/ no oxygen environment
Why is it important to eliminate moist environments in hospitals?
Bacteria will grow in most moist environments
Name and define the 3 principle routes for transmission of infectious microbes (C,V,V)
- Contact - can be done with direct, indirect contact or droplet transmission
- Vehicle - transmission of infectious microbes with an agent like food, water, air, blood or medication. With vehicle transmission it is common for several of people to get sick at the same time
- Vector - insects that carries infectious organisms from one host to another (example: mosquitoes)
What are the four factors that influences host susceptibility?
- Age
- Health
- Immune status of an individual
- Dose of infectious agent individual was exposed to
How can an individual become a less susceptible host against a disease causing microbe?
By either recovering against the infection or getting a vaccination against the microbe
What are the 4 portals of entry for infectious micro organism? (S,M, P, P)
- Skin via hair follicles or sweat glands if skin is moist
- Mucous membrane - includes the respiratory, gastrointestinal and genital tracts.
- Placenta - only a few can pass through - rubella virus/ German measles, viruses causing hepatitis B and AIDs
- Parental route (think poke) - micro organisms/ contaminated punctures, bites, cuts, surgical wounds and trauma injuries that enter/ intravenous or intramuscular injection that by pass the gastrointestinal tract
What are disease recognized by?
Signs and symptoms. Each disease has its own signs and symptoms
Define signs
Is observed by examining the patient.
Define symptoms
Characteristics of the disease that can only be observed or felt by the patient
What happens if infectious micro organisms get pasts the human body defenses?
The mucous membrane, acids of the digestive system and a number of indication (fever, lymph node swelling and inflammation) occurs
Define fever/ pyrexia
It is when the body temperature increases + 1 degree Celsius
What does getting a fever do? (3 things)
- Increases the body temperature by 1 degree Celsius
- Speeds up metabolic rate in body cells
- May facilitate phagocytosis (white blood cells eating up infectious cells) and tissue healing
How can one monitor a patient’s conditions?
Measure their fever; fever is one of the few measurable signs
What is the lymphatic system?
It is a series of vessels that drains fluid from tissues, passes through lymph nodes and returns it to the blood stream
Name 2 reasons why lymph nodes swell during infections
- Microbes from tissue fluid are being trapped in a lymph node. Microbes can then multiply and cause infection
- Multiplication of lymphocytes (responsible for immunity) which are located in lymph nodes
What does one single swollen lymph node mean?
One infected lymph node
What does multiple swollen lymph node mean?
Immune system responding to the micro organism
What are the 3 locations where the lymph nodes are closest to the skin and what are the nodes called?
- Neck –> Cervical nodes
- Under arms –> axillary nodes
- Groin area –> inguinal nodes
What is the chemical that gets released and starts inflammation when micro organisms are invading?
Histamine
What are the 4 signs of inflammation?
- Heat
- Pain
- Swelling
- Redness
What causes the heat and redness when inflammation happens?
Histamine happens with vasodilation (blood vessels widening) which increases blood flow to injured site.
What causes swelling and pain when inflammation happens?
Histamine increases permeability of blood vessels and fluid leak from vessels to surrounding tissues
What are the 4 steps inflammation help host of clearing infectious micro organisms?
- Increased number of white blood cells get attracted to the area.
- The white blood cells then produce antigens to activate antibodies.
- The antibodies then coat the bacteria in preparation for phagocytosis / neutralizes the toxins.
- Clotting elements from blood also move to injured site to surround and isolate microbes.
What are 2 infection signs that result from inflammatory response?
- Purulent exudate: Is pus/ white blood cells that died in action
- Leukocytosis: Increased number of white blood cells
Which part of the human body are sterile?
Tissue, blood, cerebrospinal fluid
Define normal flora
Are micro organisms that live on that part of the body and do not produce disease in normal circumstances
Do different body sites have the same normal flora?
No, different body sites have different normal flora (ex. the normal flora in the mouth is different than the normal flora on the skin)