Transcript TOPIC: Immunity AIM: How does the immune system protect the

Topic: Immunity
Aim: Describe the structure and role of
pathogens in causing disease.
Do Now:
HW: Castle Learning due on Thursday.
Schistosoma mansoni (fluke) is a
major parasitic pathogen that causes
schistosomiasis.
You can become infected when your
skin comes in contact with
contaminated freshwater.
Schistosomiasis account for greater
than a quarter of a million deaths
per annum. Worms not found in the
U.S.
Within days after becoming infected,
they may develop a rash or itchy
skin. Within 1-2 months of infection,
symptoms may develop including
fever, chills, cough, and muscle
aches. Symptoms of chronic
schistosomiasis include: abdominal
pain, enlarged liver, blood in the
stool or blood in the urine, problems
passing urine, and increased risk of
bladder cancer.
Immune
System
• Helps protect the
body against disease
Pathogen
• Disease-causing
microorganism
• Ex: bacteria, viruses,
parasites, or fungi
How does • Physical barriers:
the body
prevent
pathogens
from
entering?
• Skin, mucus, sweat, tears,
saliva, cilia, digestive enzymes
Antigen
• Substance that triggers an
immune response
• Found on surface of pathogens
•
Protein
that
helps
Antibodies
destroy pathogens
• Produced when an
antigen enters the
body
• Bind to
SPECIFIC
antigens to
help destroy
pathogen
Infectious • Caused by a pathogen
disease
• Can be transmitted
• Ex: cold, flu, bronchitis,
strep throat, chicken pox,
HIV (AIDS)
AIDS
• Infectious
• Acquired Immune
Deficiency Syndrome
• Caused by HIV (Human
immunodeficiency virus)
• Breaks down the immune system so
that the body can’t fight off
pathogens
• Transmitted by:
–Contact with infected blood
–Sharing infected
intravenous needles
–Sexual contact with an
infected person
Noninfectious • Not caused by a
pathogen
disease
• Cannot be
transmitted
• Ex: cancer, genetic
disorders, allergies
Allergies
• A reaction to
HARMLESS
substances
(allergens)
• Produces
HISTAMINES
which cause
symptoms
Cancer
• Abnormal
cells grow &
divide
uncontrollably
• May form
tumors
Let’s summarize…
1. Explain what a pathogen in.
2. Explain the difference between an
antigen and an antibody.
3. Explain what occurs when a foreign
antigen enters the body
4. Explain the difference between
infectious and noninfectious disease.
1. Which phrase does not describe a way
the human body responds to fight
disease?
a. destruction of infectious agents by white
blood cells
b. production of antibodies by white blood
cells
c. increased production of white blood cells
d. production of pathogens by white blood
cells
2. Which substances may form in the human body due
to invaders entering the blood?
a. nutrients
b. vaccines
c. antibodies
d. red blood cells
3. Which statement best describes an immune
response?
a. It always produces antibiotics.
b. It usually involves the recognition and destruction of
pathogens.
c. It stimulates asexual reproduction and resistance in
pathogens.
d. It releases red blood cells that destroy parasites.
4. Which statement does not identify a
characteristic of antibodies?
a. They are produced by the body in response to
the presence of foreign substances.
b. They may be produced in response to an
antigen.
c. They are nonspecific, acting against any
foreign substance in the body.
d. They may be produced by white blood cells.
5. Part of the body’s first line of defense against
disease-causing organisms is
a. the immune system b. the skin
c. antibodies
d. interferon
6. Molecules that are foreign to your body are
called
a. antibodies b. white blood cells
c. antigens
d. histamines
Which statement best describes an immune
response?
a. It always produces antibiotics.
b. It usually involves the recognition and
destruction of pathogens.
c. It stimulates asexual reproduction and
resistance in pathogens.
d. It releases red blood cells that destroy
parasites.
A(n) __ is a substance made by an organism in
response to invading substances and diseasecausing organisms.
a. allergen
b. antibody
c. antigen
d. pathogen
The immune system of humans may respond to
chemicals on the surface of an invading
organism.
1. What are these chemicals on the surface
called?
2. Explain what will happen once these
chemicals enter the body.