Chapter 15 Flashcards
The ability to cause disease is known as ______
Pathogenicity
The degree of pathogenicity is known as ________
virulence
______ adhere to host tissues
microbes
_______ damage host tissues
microbes
_____ are toxins or microbial waste products
microbes
What are the four portals of entry?
- Mucous membranes
- Skin
- Parenteral route
- Preferred portal of entry
How many portals of entry are portals via mucous membranes?
Four
What are the four sub-portals via mucous membrane?
- Respiratory tract
- Gastrointestinal tract
- genitourinary tract
- Conjuctiva
Conjuctiva is a mucous membrane portal of entry. What falls under conjuctiva? What are three infections of conjuctiva?
Eyelids and covers the whites of eyelids.
- conjunctivitis
- Trachoma
- Opthalmia neonatorum
The genitourinary tract is a mucous membrane portal of entry. What does that entail?
It’s sexually contracted. Causes HIV, genital warts, chlamydia, and syphillis
The gastrointestinal tract is a mucous membrane portal of entry. What does that entail?
Food, water, contaminated fingers. Causes giardia, shigellosis, and cholera
The respiratory tract is a mucous membrane portal of entry. What does that entail?
The nose and mouth. Causes the common cold, influenza, and pneumonia
The skin is a portal of entry. Microbes gain access through….
hair follicles and sweat gland ducts.
What is interesting about skin?
Largest organ in the body
What is parenteral?
administered or occurring elsewhere in the body than the mouth and alimentary canal.
Parenteral is a port of entry. How do microbes enter the tissue?
Microbes are deposited directly into tissues when barriers are penetrated
Parenteral ports of entry include….
Punctures, injections, bites, cuts, surgery, and dry skin
What diseases can someone contract via parenteral ports?
HIV, hepatitis viruses, tetanus and gangrene
What is the preferred route?
Microbes causing infections through their specific portal of entry
What is the preferred route for Salmonella typhi?
Signs and symptoms identified when swallowed. Gastrointestinal tract. No reaction on skin
What is the preferred route of Streptococcus pneumonia?
Inhaled…respiratory tract. No signs noticed if swallowed.
What is the preferred route for Bacillus anthracis?
More than one entry.
IDv50
Infectious dose for 50% of a sample population. Measures virulence of a microbe
LDv50
lethal dose for 50% of a sample population. Measures potency of a toxin.
How many endospores enter tissue via skin? (Bacillus anthracis)
10-50
How many endospores enter body through inhalation? (Bacillus anthracis)
10,000-20,000
How many endospores enter the body through ingestion? (Bacillus anthracis)
250,000-1,000,000
What is the name used when measuring the virulence of a microbe?
IDv50
What is the name used when measuring the potency of a toxin?
LD50
LD50 is _____ and ID50 is ____
lethal; infectious
What is the lethal dose of Botulinum?
0.03 ng/kg
What is the lethal dose of Shiga toxin?
250 ng/kg
What is the lethal dose for Staphylococcal enterotoxin?
1350 ng/kg
adherence vs adhesins
Adherence is pathogens attaching to the host tissues whereas adhesins is after they’ve attached and the pathogens bind to receptors on the host cells (ligands)
______: pathogens attach to host tissues
adherence
_____ on the pathogen bind to receptors on the host cells
adhesins (ligands)
______ and ______ are two types of adhesins
Glycocalyx and Fimbriae
Microbes form _____ (share nutrients)
Biofilms
What are glycocalyx and fimbriae?
adhesins that pathogens use to bind to the host cells
What are the three ways bacteria penetrate host defenses?
- Capsule
- Enzymes
- Cell wall components
