Ch. 21 Immune System A&P
What is a cytokine? What are some examples of cytokines?
Cytokines are cell signalling molecules that aid cell to cell communication in immune responses and stimulate the movement of cells towards sites of inflammation, infection and trauma. Examples of cytokines include the agents interleukin and the interferon which are involved in regulating the immune system's response to inflammation and infection.
What is the difference between adaptive and innate immunity?
Innate immunity refers to nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body. The innate immune response is activated by chemical properties of the antigen. Adaptive immunity refers to antigen-specific immune response. The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates an army of immune cells specifically designed to attack that antigen. Adaptive immunity also includes a "memory" that makes future responses against a specific antigen more efficient.
What is the difference between natural and artificial immunity?
Naturally acquired: exposed to pathogen in daily life and created antibodies and memory cells, ex. chickenpox artificially acquired: injected with weakened pathogen or it contained the antibodies
What is the difference between self and nonself?
Self antigens are marker molecules on the surface of individual cells in a multicellular organism such as mammals which indicate that cell to be a part of the organism. Non-self antigens are markers on cells and tissues which may have entered the organism -eg. transplant, virus, bacteria, and which the body's immune system recognises as foreign and as a result will initiate an immune response.
What is the role of macrophages in the defense of the body?
The term "macrophage" conjures images of a hungry white blood cell gobbling invading bacteria. However, macrophages do much more than that: Not only do they act as antimicrobial warriors, they also play critical roles in immune regulation and wound-healing. They can respond to a variety of cellular signals and change their physiology in response to local cues.
Why are the skin and mucous membranes together called the body's first line of defense?
These membranes provide everlasting layers of densely packed cells and other materials, that protects the internal environment from invasion by foreign cells.
What is the difference between active and passive immunity?
active: develops naturally in response to infection or artificially through immunization. passive: when individual receives antibodies, (those passed to fetus across placenta and to infants milk)
