HED Exam 4 Questions and Answers
What is a pathogen, and what are the various routes (and their definitions) of transmission of
pathogens? - Answer-Pathogen - disease causing agent; ubiquitous
When a pathogen is virulent, it is strong enough to overcome host resistance and cause disease.
Routes of Transmission:
Direct contact
Indirect contact
Food-, air-, or water-borne
Animal-borne
Perinatal
Autoinoculation (transmit a pathogen from one part of your body to another)
Explain your body's defense against infection: what are the physical and chemical defenses? Know the
definitions for terms and be familiar with examples of the terms that are listed in your textbook. -
Answer-Skin (Our most critical early defense system; allows few pathogens to enter) - physical barrier
Body Secretions (sweat, oil glands, earwax, tears)
Kill or repel invaders
,Mucous membranes/internal linings
Trap, engulf pathogens
Contain enzymes that destroy or slow pathogenic reproduction
Enzymes & Compounds in blood
Kill invader; Detoxify harmful chemicals
Body's final line of defense
Immune response
Immunity - resisting a disease by counteracting the substance that produces it
Antigen - foreign body that triggers immune response
Antibodies - proteins produced to destroy and lessen effects of antigens
Artificially acquired active immunity
Immunizations
killed, weakened, or toxic pathogens are injected or taken orally
--------------------------------------------------------------
EXAMPLES:
- Enzymes in body secretions such as sweat provide additional protection, destroying microorganisms on
skin surfaces by producing inhospitable levels of pH
- Internal linings, structures, and secretions of the body provide another layer of protection (ie, mucous
membranes in the respiratory tract trap and engulf invading organisms. Cilia in the lungs and resp. tract
, sweep invaders toward body openings. Nose hairs trap airborne invaders. Tears and earwax contain
enzymes that destroy or neutralize pathogens.
What is an antigen? Antibodies? - Answer-Antigen is a substance capable of triggering an immune
response. Includes a virus, bacterium, fungus, parasite, toxin, or tissue or cell from another organism.
Antibodies are substances produced by the body that are individually matched to specific antigens.
humoral immunity - Answer-body's major defense against many bacteria and toxins they produce; is
mediated by antibodies secreted by white blood cells!
What is an autoimmune disorder? - Answer-Disease caused by an overactive immune response against
the body's own cells.
(Common autoimmune disorders include rheumatoid arthritis, lupus, type 1 diabetes, celiac disease, and
multiple sclerosis.)
Why do we experience inflammation, pain, and fever (p.401)? - Answer-The 4 signs of inflammation are
redness, swelling, pain, and heat. When an infection is localized, these symptoms occur.
Pain is one of the earliest signs that an injury or infection has occurred. Pathogens killing/injuring tissue
at the site of infection causes swelling that puts pressure on nerve endings. This plays the valuable role
of causing a person to avoid activity that aggravates the injury.
Another indicator of infection is fever, or a body temp. above 98.6 degrees F. It's caused by toxins
secreted by pathogens that interfere with the control of body temp. and a fever also stimulates the
body to produce more white blood cells. A mild fever is protective, but a fever beyond 101 degrees
increases risk.
What is a pathogen, and what are the various routes (and their definitions) of transmission of
pathogens? - Answer-Pathogen - disease causing agent; ubiquitous
When a pathogen is virulent, it is strong enough to overcome host resistance and cause disease.
Routes of Transmission:
Direct contact
Indirect contact
Food-, air-, or water-borne
Animal-borne
Perinatal
Autoinoculation (transmit a pathogen from one part of your body to another)
Explain your body's defense against infection: what are the physical and chemical defenses? Know the
definitions for terms and be familiar with examples of the terms that are listed in your textbook. -
Answer-Skin (Our most critical early defense system; allows few pathogens to enter) - physical barrier
Body Secretions (sweat, oil glands, earwax, tears)
Kill or repel invaders
,Mucous membranes/internal linings
Trap, engulf pathogens
Contain enzymes that destroy or slow pathogenic reproduction
Enzymes & Compounds in blood
Kill invader; Detoxify harmful chemicals
Body's final line of defense
Immune response
Immunity - resisting a disease by counteracting the substance that produces it
Antigen - foreign body that triggers immune response
Antibodies - proteins produced to destroy and lessen effects of antigens
Artificially acquired active immunity
Immunizations
killed, weakened, or toxic pathogens are injected or taken orally
--------------------------------------------------------------
EXAMPLES:
- Enzymes in body secretions such as sweat provide additional protection, destroying microorganisms on
skin surfaces by producing inhospitable levels of pH
- Internal linings, structures, and secretions of the body provide another layer of protection (ie, mucous
membranes in the respiratory tract trap and engulf invading organisms. Cilia in the lungs and resp. tract
, sweep invaders toward body openings. Nose hairs trap airborne invaders. Tears and earwax contain
enzymes that destroy or neutralize pathogens.
What is an antigen? Antibodies? - Answer-Antigen is a substance capable of triggering an immune
response. Includes a virus, bacterium, fungus, parasite, toxin, or tissue or cell from another organism.
Antibodies are substances produced by the body that are individually matched to specific antigens.
humoral immunity - Answer-body's major defense against many bacteria and toxins they produce; is
mediated by antibodies secreted by white blood cells!
What is an autoimmune disorder? - Answer-Disease caused by an overactive immune response against
the body's own cells.
(Common autoimmune disorders include rheumatoid arthritis, lupus, type 1 diabetes, celiac disease, and
multiple sclerosis.)
Why do we experience inflammation, pain, and fever (p.401)? - Answer-The 4 signs of inflammation are
redness, swelling, pain, and heat. When an infection is localized, these symptoms occur.
Pain is one of the earliest signs that an injury or infection has occurred. Pathogens killing/injuring tissue
at the site of infection causes swelling that puts pressure on nerve endings. This plays the valuable role
of causing a person to avoid activity that aggravates the injury.
Another indicator of infection is fever, or a body temp. above 98.6 degrees F. It's caused by toxins
secreted by pathogens that interfere with the control of body temp. and a fever also stimulates the
body to produce more white blood cells. A mild fever is protective, but a fever beyond 101 degrees
increases risk.
