3.1 features of innate and adaptive immunity
Immunity
- Functions
- Prevent pathogens/toxins from entering the body
- Eliminating any foreign pathogens, cancer or transplated cells from the body
- Initiate wound healing
- Recognize “self” compared to foreign antigens (self tolerance) - Three Lines
of Defense
- 1. Chemical and Physical Surface Barriers (skin)
- 2. Internal Cellular and Chemical Defenses (ex. Phagocytes, antimicrobial
proteins, inflammatory process, fevers)
- 3. Immune Response to a Specific Pathogen (lymphocytes made antibodies and
components to seek and kill infected cells)
- Innate Defenses (born with and typically all ppl have them)
- Surface/Chemical Barriers (keeping pathogens from entering the body)
- skin/mucosa
- sweat/urine
- Mucous
- tears/saliva
- Stomach acid
- Internal Defenses (fight pathogen if they make it inside the body)
- Phagocytes
- NK cells
- Inflammation
- Fever
- Antimicrobrial proteins
- Complement system - Cell types
- Granulocytes (leukocytes that contain granules)
- Neutrophils - early responder in innate immunity & use phagocytosis to kill
microbes
- Eosinophils - become active in parasitic infections and allergic responses
- Basophils - release histamine and proteolytic enzymes, believed to play role in
allergic and parasitic infections - Angranulocytes (leukocytes that lack
granules)
- Monocytes - released from bone marrow and mature into macrophages and
dendritic cells where they engage in the inflammatory response and phagocytize
foreign substances and cellular debries
, - Macrophages - long life span, reside in tissues and are the first phagocyte that
organisms encounter. Work with neutrophils on behalf of host’s initial defense
system
- Lymphocytes
- Natural killer (NK) cells: can spontaneously kill target organisms, can kill some
tupes of tumor or infected cells w/out previous exposure to surface antigen. Limit
the spread of infection and assist in development of adaptive immune responses
through cytokine production. Can help with dendritic cell maturation and innate
immune control of viral infections
- Denritic cells (DC): found as immature cells in lyphoid tissue. There they
capture foreign agents and transport then to peripheral lymphoid organs. Once
activated, they undergo a complex maturation process as they migrate to the
regional lymph nodes. They function as key antigen presenting cells (APC)
capable of initiating adaptive immunity. Serve important role between innate and
adaptive immunity.
- Adaptive Defenses (aquired defenses) - Humoral Immunity
- B lymphocytes
- Antibodies
- Cellular Immunity
- T lymphocytes
- Features
- Is systemic
- Is specific
- Has memory
- Two separate overlapping arms
- Humoral (antibody-mediated) immunity
- Cellular (cell-mediated) immunity - Cell Types