Chapter 48 Flashcards
Immunity
is a resistance to or protection against a
disease-causing pathogen
immune system of the animal
is responsible for
defending animals against pathogens
The immune system success depends on three key
processes:
- Preventing the entry of potential pathogens
- Detecting the presence of a pathogen by distinguishing
it from the animal’s own body - Eliminating the pathogen
innate immune system
first line of defense
and includes barriers to entry
Includes: Mucus, Lysozyme, wax in ears, oil on skin
Mucus
Mucus is a sticky fluid made of glycoproteins (proteins and water) that catches germs and carries them away.
Lysozyme,
an antibiotic that occurs in tears
- Leukocytes
(white cells) provide an immediate, generic
response against broad groups of pathogens
The inflammatory response
(Innate Immune Response at Injury Site)
Pathogens enter through a wound.
Platelets release clotting proteins to stop bleeding.
Macrophages and injured tissues release signals to attract immune cells.
Mast cells release histamine, making blood vessels wider and more permeable.
Neutrophils arrive to kill and remove pathogens.
Macrophages clean up pathogens and help repair tissue.
This process helps fight infections and heal wounds!
The adaptive immune response
- Is based on interactions between
specific immune system cells and a specific antigen
antigen
A molecule capable of inducing an
immune response (red flag)
antibodies
are proteins made by the immune system that recognize and bind to specific antigens (like viruses or bacteria) to help neutralize or destroy them.
The four key characteristics of the
adaptive immune response
Specificity – Antibodies and immune cells target only specific parts of specific invaders.
Diversity – The immune system can recognize almost any foreign substance.
Memory – It responds faster and stronger if the same invader attacks again.
Self vs. Nonself – It knows the difference between the body’s own cells and harmful invaders.
B cells
mature in bone marrow
* Produce antibodies
T cells
mature in the thymus
* Recognize and kill host cells
that are infected
The adaptive immune response
has two mechanisms:
- cell-mediated response: occurs by cell-to-cell contact
- humoral response: involves the production of antibodies and other proteins secreted into blood
and lymph
Immunological Memory (Adaptive Immunity):
Memory cells (from B and T cells) stay in the body for years, ready to fight the same invader again.
Vaccines expose the body to a harmless version of a pathogen to create memory cells.
If reinfected, memory cells act fast, stopping illness before it starts.
allergy/ allergic reaction
is an abnormal
overreactive response to an antigen
* Molecules that trigger this response are called allergens
autoimmunity
An immune response directed against its own healthy
molecules or cells
Immunodeficiency diseases
badly impair the adaptive
immune response
