Introduction to Immunology Flashcards
What would happen if we didn’t have an immune system?
We would be overcolonised by many different organisms
Resulting in the failure and loss of the integrity of our organ system
Death
Why do we need an immune system?
We are essentially a warm bag of food
Our blood & extracellular fluid is full of proteins and sugars
Our constant internal temperature encourages growth
Define Immunology
Is the study of the immune system
Define Immunity (Resistance)
Is the ability of the body to prevent disease, damage or infection using our defence mechanisms
Define Vulnerability
Is termed susceptibility
What are the two types of immunity?
Innate immunity and .Adaptive immunity
Define Non Specific immunity
Refers to the defences present at birth
It does not involve specific recognition of a microbe
It acts against all microbes in the same way
What makes up the first line of Physical and chemical barriers?
Skin
Mucus membranes
Secretions
Cilia
What is the role of the intact Skin epidermis?
Forms mechanical barrier that prevents entry of pathogens and other harmful substances
What is the role of the intact Acid Mantle?
Skin secretions (perspiration and sebum) make epidermal surface acidic, which inhibits bacterial growth, sebum also contains bactericidal chemicals
What is the role of the intact Keratin?
Provides resistance against acids, Alkalis and Bacterial enzymes
What is the role of the intact Intact mucous membranes?
Form mechanical barrier that prevents entry of pathogens
What is the role of the Mucus?
Traps microorganisms in respiratory and digestive tracts
What is the role of the Nasal Hairs?
Filters and trap microorganisms in passages
What is the role of the Cilia?
Propel debris-laden mucus away from lower respiratory passages
What is the role of the Gastric Juice?
Contains concentrated hydrochloric acid and protein-digesting enzymes that destroy pathogens in the stomach
What is the role of the Acid Mantle of vagina
Inhibits growth of most bacteria and fungi in female reproduction tract
What is the role of the Lacrimal secretion (tears), saliva?
Continuously lubricate and cleanse eyes (tears) and oral cavity (saliva), contains lyzozyme, an enzyme that destroys microorganisms
What is the role of Urine?
Normal acid pH inhibits bacterial growth, cleanses the lower urinary tract as it flushes from the body.
What is in the second line of defense?
Antimicrobial substances / processes / cells
Natural killer cells
Basophils / Eosinophils
Neutophils
Macrophages
Inflammation / Fever
What are the two roles of the Dendritic cells?
Have a phagocytic role in the innate immune system
Activate the adaptive immune system
Define Specific immunity
Refers to the defences that involve specific recognition of a microbe
Once it has breached the innate immunity defences
It is based on a specific response to a specific microbe
It is able to adapt/adjust to handle specific microbes
What are the main components of adaptive immunity?
Lymphocytes (Type of white blood cells)
T Lymphocytes (T Cells)
B Lymphocytes (B Cells)
Dendritic cells
What are components of Humoral immunity?
B cells / Plasma Cells
Antibody immunity
Can involve “classical” complement
What are the components of Cell mediated (Cellular) Immunity?
T cells
Activation of macrophages & NK cells
Release of cytokines (chemical mediators)
Delayed Type Hypersensitivity (DTH)
AKA –Type IV Hypersensitivity
Antibody independent (Takes 2-3 days to develop)
What are the components of a Neutrophil?
Multilobednucleus
- Commonest leucocyte
- 2500-7500/mm3 of blood
- A short-lived phagocytic cell
- Contains granules
- Full of numerous bactericidal substances
- Proteases / MPO > Hypochlorite / Defensins
What is the role of Neutrophils?
They undergo Phagocytosis and the killing of Microorganisms
How do Neutrophils interact with the Adaptive immunity?
- “opsonised” by IgGor complement
- Opsoniummeans ‘relish’ (tagged for phagocytosis)
- Functions as effector cell of humoral immunity