Unit 23: The Animal Immune System Flashcards
(39 cards)
What are pathogens?
All organisms are targets for diseases from pathogens, disease-causing organisms.
What are examples of pathogens?
The pathogens include bacteria, parasites, viruses, fungi, and protists.
What is immunity?
Is a resistance to or
protection against a disease causing pathogen. The immune system of the animal is responsible for defending animals against pathogens.
What is innate immunity?
No adaptation: Type of
response does not vary when infections reoccur. Generic response against any type of pathogens.
What is adaptive immunity?
Adaptation and memory:
Response is more rapid and efficient when infections reoccur. Specific response against
pathogen strains.
How does mucus protect against pathogens?
Soft-bodied invertebrates are covered with a protective layer of mucus—a slimy mix of glycoproteins and water that traps pathogens.
How does protein keratin protect against pathogens?
Human skin has a layer of dead cells that are reinforced with tough fibers of the protein keratin.
What is an example of an outer surface that protects against pathogens?
In humans, the oil secreted by your skin cells is converted to fatty acids by bacteria that live harmlessly on your body.
Which cells are primarily involved in the innate immune response?
Leukocytes (white blood cells) that provide an immediate, generic response against broad groups of pathogens.
How are leukocytes alerted to the presence of pathogens?
By detecting antigens on the surface of pathogens, which are absent on host cells.
What is the inflammatory response?
A multi-step innate immune response that occurs at the site of injury to prevent infection and promote healing.
What is the first step of the inflammatory response?
A break in the skin allows pathogens to enter the body.
What happens if blood vessels are damaged at the site of injury?
Platelets release proteins to form blood clots, and other clotting proteins create cross-linked structures to reduce bleeding and wall off the wound.
What do wounded tissues and macrophages release, and what is their role?
They release chemokines, signaling molecules that form a gradient to recruit immune cells to the wound.
Which cells release histamine, and what does it do?
Mast cells secrete histamine, which dilates blood vessels and makes them more permeable, allowing immune cells to exit and reach the tissue.
Which immune cells arrive first at the infection site and what do they do?
Neutrophils are the first responders. They exit blood vessels and phagocytose pathogens (engulf and digest them).
What happens after neutrophils arrive?
Other leukocytes arrive and mature into macrophages, which continue to secrete chemokines and produce cytokines.
What is the adaptive immune response?
A specific immune response that targets specific antigens using lymphocytes and antibodies.
What makes the adaptive immune system different from the innate immune system?
The adaptive system is specific and has memory, allowing it to respond more effectively to previously encountered pathogens.
What are lymphocytes?
A type of white blood cell central to the adaptive immune system, including B cells and T cells.
Where are lymphocytes produced?
In the bone marrow.
Where do B cells and T cells mature?
- B cells mature in the bone marrow.
- T cells mature in the thymus
Where are lymphocytes activated?
In lymph nodes and the spleen, when they encounter specific antigens.
What two things do B cells do?
- B cells produce antibodies to attack invaders outside of cells
- Each B cell produces one specific antibody
