Test #1 New Review Flashcards
Infection
the process by which an “infectious agent” enters a host.
Evasion-
Alarm system that doesn’t work :
the “infectious agent” multiplies, spreads, by escaping the host’s immune system.
Pathogenicity
studying the ability (or inability) of a germ to cause disease
Invasion
the “infectious agent” establishes itself, multiplies, and spreads after infecting the host.
Pathology
study of such diseases.
Virulence
the degree of pathogenicity/ *how sick you can get/severely sick or life threatening
Scientists who supported Spontaneous Generation
Louis Pasteur and Robert Koch
Scientists associated with Microscopy
- Antoni van Leeuwenhoek: invented the Simple Microscope which used natural light to produce a magnified image with just one lens.
- Robert Hooke: invented a Compound Microscope which combines lenses to enhance magnification at opposite ends of an Optical Tube that forms the Body of the Microscope
Define the Germ Theory of Disease
The pioneering discoveries of Louis Pasteur and Robert Koch led to the “Germ Theory of Disease” that linked germs, which we contract from contaminated air, infected folks, or infested places, to spoilage, decay, decomposition, and human diseases.
Etiology
the study of what causes infections and diseases.
Koch’s Postulates
- The pathogen must be present in every occurrence of the Disease and
- Must be isolated in pure culture and identified by its characteristics
- When the isolate is intentionally injected into a healthy host
- It must reproduce symptoms of the disease in the new host
- Pathogen from new host must match profile of original pathogen.
What does each one say about infectious agents?
conclusively linked a particular pathogen to its specific disease symptoms.
Therefore, Microbiology introduces health professionals to Micro-organisms or ‘Microbes’ that are too small for natural eyes, unlike more familiar organisms that we come across in everyday life.
Pathogens vs. Non-Pathogens
Pathogens= harmful Non-Pathogens= not harmful
Disease vs. Opportunistic Pathogens
Disease= particular kind of illness caused by bacteria or an infection.
Opportunistic Pathogens= infect healthy hosts without causing disease in their natural environments. When they infect other body parts, however, they may become pathogenic.
Normal Body Flora vs. Transient Flora
Normal Body Flora= permanent
Transient Flora= temporary
Nosocomial Infection vs. HAIs
Nosocomial Infections= infections that patients acquire while receiving treatment for other conditions during Hospital stay.
HAIs= this term has been extended to any infection acquired through a Healthcare Facility
Estimate Percentage of Nosocomial infections
22% Lower respiratory infections 22% Surgical site infections 17% Gastrointestinal infections 16% Other 13% Urinary tract infections 10% Bloodstream infections 8%: Cutaneous (Skin) Infections
Which Normal Flora can be found and where?
- Staphylococcus on the skin, eyes, nose, throat, mouth and urinary tract
- Streptococcus in the nose, throat, and urinary tract
- Diphtheroids on the skin, eyes, nose, throat, and urinary tract
What is the effect of Virulent?
Virulence is the degree of pathogenicity. Virulent microbes are pathogenic and capable of causing diseases with life-threatening symptoms.
Non-Virulent?
Non-virulent strains have low degree of pathogenicity and may not be non-pathogenic; however, their mild symptoms make them useful as potential vaccines.
Avirulent agents?
Avirulent microbes are essentially non-pathogenic
Compare Imperial and Metric System Measurements
Size
Temperature
Weight
Volume
IMPERIAL:
- Size: Yards, ft, and inches (yd, ft, in)
- Temperature: Fahrenheit
- Weight: Pounds & Ounces (lbs. & oz)
- Volume: Gallons, Cubic ft, & Cubic inches
METRIC SYSTEM:
- Size: Meter (M)
- Temperature: Celsius
- Weight : Gram (G)
- Volume: Liter (L)
Determine the symbols and relationships of these Metric sub-units:
Deci- Micro-
Centi- Nano-
Milli- Pico-
Meter (M) Gram (G)
deci- d- 1/10 dm -
centi- c- 1/100 cm -
milli- m- 1/1000 mm mg
micro- u- 1/million um ug
nano- n- 1/billion nm ng
pico- p- 1/trillion pm pg
All go in increment by (x) 10
Compare Simple and Compound Microscopes
“Simple Microscope” was invented by Antoni van Leeuwenhoek and used natural light to produce a magnified image with just one lens.
“Compound Microscope” is built on the original replica of Robert Hooke, and combines lenses to enhance magnification at opposite ends of an Optical Tube that forms the Body of the Microscope.
Name Microscope Parts and identify their functions
- Ocular lenses: the lens at the top that you look through- 10X or 15X power.
- Tube: Connects the eyepiece to the objective lenses
- Objective lenses: Basically a housing for a lens. 4X, 10X, 40X, and 100X.
- Stage: The specimen slides rests on this part of the microscope.
- Base: supports the microscope
- Arm: contains the housing for the fine and coarse adjustments and connects the base of the microscope to the nosepiece and ocular.
- Coarse adjustment knobs: The larger of the two knobs move the stage up or down making things larger or smaller.
- Fine adjustment knobs: The smaller of two sets of knobs located on either side of the arm. This adjustment is used to make small adjustments in focusing.
- Light source: Located directly under the stage.
- Adjustable diaphragm: This rotating wheel on the underside of the stage allows the user to adjust the amount of light that passes through the specimen.
Identify the lenses of a Compound Microscope
The Ocular Lens boosts an Objective lens by re-magnifying its image before the viewer sees it. The combined magnification of both lenses is Total Magnification, which multiplies the Magnifying power of any Objective lens by the Ocular lens (usually x10). The Scanning Objective Lens (4x lens) makes the image just a little bigger than the original and is best used for searching. The powerful 100x objective lens produces a final image that looks 1,000 times larger than the real specimen, making the magnified image appear unstable.
Name Objective lenses, their magnifying powers, and color codes.
First, the Objective Lens at one end of the optical tube enlarges an image of the specimen using lenses that magnify 4x(Red), 10x(Yellow), 40x(Blue), or 100x(White). Each Objective lens is color-coded for easy identification. An Ocular Lens at the opposite end of the optical tube re-magnifies the enlarged image from the objective lens 10X more.
How to calculate Total Magnification
To get the total magnification take the power of the objective (4X, 10X, 40X) and multiply by the power of the eyepiece, usually 10X.
Define Resolution
the ability of the lenses to reveal fine DETAILS and structure.
Define Useful Magnification-
is any increase in magnification that produces a higher resolution and reveals NEW DETAILS.
Define Empty Magnification- Bigger screen TV
increase in magnification that does not improve resolution or reveal any new details.
Compare Human Eye Resolution to
4x Objective lens 10x Objective lens
40x Objective lens 100x Objective lens
If a RBC is 5um, which lens would you need to see it?
How much detail whit a 400X objective lens?
The Scanning Objective lens has a total magnification of 40 times (4 x 10). Compared to the human eye, this is sufficient to make an average cell of 5 micrometers (5 mm), which is below the resolution of the Human eye, to appear like it is 200mm. exp. 5*40=200mm
Low-Power objective lens, with Total Magnification of 100 (10 x 10), makes average microscopic bacteria of about 2.0 mm appear like 200mm, which will not be possible with the Scanning Lens. exp. 100*2.0=200
The High Power Lens (40 x 10) yields higher resolution that can make internal cell organelles of 500nm in size look like 200mm; the low-power lens lacks the resolving capacity to make such a structure visible.
Therefore, a more powerful Objective lens (100x10) achieves Useful Magnification compared to the previous one or the Human Eye. The oil immersion objective lens extends useful magnification to 200 nanometers because it has total Magnification of 1,000x.
Limit of human eye resolution is about 200 micrometers.
Question answers: 5*40=200um
200/400=.5 x 1000nm=500nm
Generally,
the increase in magnification can improve resolution and reveal new details.
