Immune System Flashcards
What are the two immune systems?
Innate and adaptive
Leukocyte
-white blood cells
- mobile army of protective cells
- protect against pathogens
Types of Leukocytes
Granulocyte: large, short lived, contain membrane-bound cytoplasmic granules
Agranulocyte: white blood cell with no granules
Neutrophil
Structure and Function
Structure
- multi lobed nucleus with granules
- contains defensin
Function
- phagocyte eats cells (bacteria slayer)
- increase in # during infection
-chemically attracted to inflammation
Eosinophils
Structure and Function
Structure
- bilobed nucleus with red granules (contains digestive enzyme)
Function
- lysosome breaks apart (digest paracydic worms)
- complex role in allergies and asthma
Basophils
Structure and Function
Structure (rare)
- bilobed nucleus with black/purple granules (contains histamine)
Function
- releases histamine (inflammation/vasodilation)
Lymphocytes
Structure and Function
Structure
- spherical, nucleated cells
Function
- T cells: viruses/tumors
-B cells: produce antibodies
-NKC: kill cancer cells/virally infected cells
Monocytes
Structure and Function
Structure
- u/kidney shaped nucleus
Function
- macrophage (big digester)
- viruses and chronic infections
Innate Surface Barriers
- skin
- mucous membranes
Cell / Chemical Innate Defenses
- phagocyte
- natural killer cells
- inflammation
- fever
Four signs of inflammation
- Redness
- Heat
- Pain
- Swelling
Benefits of inflammation
- prevent spread of damage
- dispose of debris
- if pathogen, alerts immune system
- allows nutrients into area to repair
How does inflammation occur?
- Damage/infection causes release of histamine
- Vasodilation signals wbc to area
What is a fever?
- inhibits antigen reproduction, store’s critical nutrients
-abnormally high internal body temperature - self induced
- systematic approach
Three stages of Adaptive Defenses
- Recognize & destroy antigen
- Systematic response, not limited to region of infection
- System has memory after exposure and can recognize quicker to mount attack
Immunologic Memory
- primary response takes 3-6 days to recognize, destroy, and inform immune system
- build antibodies (peak 10 days)
Active Memory
Natural- exposed through environment and gained immunity
Artificial- exposed on purpose to gain immunity (vaccine)
Passive Memory
Natural- babies in the womb and breast milk
Artificial- given antibodies from source (in hospital)
Innate barriers
- skin
- mucous
- tears
- salvia
- sweat
- stomach acid
- nose hairs / eyelashes
Neutrophils and Macrophages
-engulf / destroy pathogens by phagocytosis
Natural Killer Cells
Release chemicals that cause death of body’s infected / cancerous cells
Anti microbial protein
- at injury site
- interferons: warn cells
- complement system: alters blood vessels permeability and blood clotting factors, allows wbc to enter
Inflammatory Response
- Basophil releases histamine & cytokine for vasodilation/ chemical messenger
- Increase in # of wbc & neutrophils
- Ingulf invaders & clot blood to stop spread
Phagocyte
Engulfs pathogen and becomes APC (Antigen Presenting Cell)
Humoral Immunity
B Cell: multiplies and differentiates
Memory Cell
Plasma Cell: releases antibodies that bind on pathogens
Cell Medicated Immunity
T Cell: binds antigen complex on an infected cell, releases perforin and granzymes
