Lecture 19 Flashcards
The Immune System
A host defense system comprising of many biological structures and processes within an organism that protects against infectious disease
Made up of two components
• Innate immunity
• Adaptive immunit
Innate Immunity
- Defenses that don’t depend on prior exposure to the disease
• Evolved before the adaptive immunity system
• Represent the body’s first line of defense against
infection and injury
• Examples of components of innate immunity
• Mucosal membranes
• Antimicrobial soluble proteins in blood, saliva and tears
• Phagocytic cells that scavenge extracellular molecules. Example: Neutraphils (type of white blood cell)
• Inflammatory response
Adaptive Immunity
• Also known as acquired or specific immunity
• Depends on prior exposure to an antigen
Defining features
• Specificity
• Diversity
• Memory
Ex of components of adaptive immunity:
* T lymphocytes ( killer T cells)
* B lymphocytes
Antigen
• A substance that elicits a specific immune response
• Most pathogens (i.e. bacteria, viruses, parasites) are composed of multiple distinct antigens
Antibody
A protein that your body builds specifically to fight a particular antigen
Autoimmune Disease
A condition arising from an abnormal immune response to a normal part of the body
• Common examples
• Celiac disease
• Diabetes mellitus type 1
• Graves’ disease
• Inflammatory bowel disease
• Multiple sclerosis
• Rheumatoid arthritis
Hygiene Hypothesis
*All living things evolved with a suite of parasites
*Bacterial and viral infections during early life direct the maturing immune system
• The lack of infections in industrialized countries due to improved hygiene and use of antibiotics may alter the human immune system such that it responds inappropriately to innocuous substances
T Lymphocytes
- A type of white blood cell
Various types of T cells:
* killer T cells (directly kill virus infected cells)
*Helper T Cells: determine if an dhow other parts of the immune system should respond to a specific threat
Microbiota
Microbiota refers to the community of tiny organisms (like bacteria, fungi, and viruses) that live in or on your body, especially in places like your gut. They help with digestion, immune function, and other bodily processes.
Commensal Relationship
- A relationship between two species where one species received benefits and the other neither benefit or is harmed
Symbiotic Relationship
*Both species benefit from the relationship
Pathogenic/Parasitic Relationship
One species benefits and the other is harmed
Functions of the Gut Microbiota
- Immune Function
*Metabolism
- Communicate with the Brain
Immune Function
- Continue cross talk between the Microbiota of the gut and the immune system helps maintain the immunological balance
Metabolism
*helps breaks down and absorb absorb nutrients, especially certain carbohydrates
Communicate with the Brain
*Microbiome gut-brain axis
*Biochemical signals from Microbiota—intestine—-brain
