The Immune System

CONTENTS

Layers of Defenses

-Barriers

-Innate Immune Responses

*Skin
*Mucous
*Flora

*Inflammation
*Complement
*Cell Barriers
*Natural Killer cells

-Adaptive Immune Responses

*Lymphocytes
*Killer T cells
*Helper T cells
*Antibodies

-Immune Memory

*Passive
*Active
*Immunization

Signs of a functioning Immune System

*Fever
*Mucous production
*Cough
*Nausea *Diarrhea

Antibiotics

Support for our Immune Systems

*Lifestyle considerations
*Diet changes
*Supplements -nutrient & herbal considerations
*Hydrotherapy

Immune Disorders

*Autoimmune
*Immunodeficiencies
*Allergies

The immune system consists of biological structures and processes within an organism that protect against disease.

To function properly, an immune system must detect a wide variety of agents, known as pathogens.

Pathogens can be things like; viruses, bacteria, fungus, and parasites.

The immune system must distinguish between these invaders and from the organism's own healthy tissue.

The immune system protects us from infection with layers of defenses, which become increasingly specific.

First, physical barriers prevent pathogens from entering our bodies.

If an organism breaches these barriers, the next layer of defense, the innate immune system is ready and waiting. This provides an immediate, but non-specific response.

If pathogens are lucky or clever enough to escape the innate response, we have another more targeted layer of protection, the adaptive immune system.

Loading...

The adaptive system is put on notice when the innate immune system activates.

Loading...

Loading...

The adaptive response creates memory cells, which improves recognition of the pathogen.

Loading...

The adaptive immune system will then mount faster and stronger attacks each time this pathogen is encountered.

Loading...

The adaptive response holds a memory of previous attacks from organisms in the same family as the current invader.

Loading...

Loading...

Surface barriers:

·     Skin

·     Mucus membranes

·     Normal flora

Loading...

Loading...

Loading...

Loading...

Maintaining healthy skin, production of mucous in the respiratory, digestive and urinary tracts is an essential first line of defense against all infections.

Loading...

Loading...

Innate immune system

The innate response is triggered when microbes are identified by certain receptors

or when damaged, injured or stressed cells send out alarm signals.

Innate immune defenses are non-specific, meaning these systems respond in a generic way.

This system does not confer long-lasting immunity against pathogens.

The innate immune system is the dominant system of host defense in most organisms.

Inflammation

Inflammation is one of the first responses of the immune system to infection. The symptoms of inflammation are redness, swelling, heat, and pain, which are caused by increased blood flow into tissue.

Inflammation is produced by eicosanoids and cytokines , which are released by injured or infected cells.

Eicosanoids include prostaglandins that produce fever and dilation of blood vessels and leukotrienes that attract certain white blood cells (leukocytes).

Cytokines are responsible for communication between white blood cells. These include:
-chemokines, which promote 'chemotaxis'
-interferons which have anti-viral effects (shutting down protein synthesis in host cells) .

Growth factors and other factors may also be released to promote healing of any damaged tissue following the removal of pathogens.

Complement system

The complement system is a biochemical cascade that attacks the surfaces of foreign cells.

Complement is the major 'humoral component' of the innate immune response.

It contains over 20 different proteins and is named for its ability to "complement" the killing of pathogens by antibodies.

Many species have complement systems, including non-mammals -like plants, fish, and some invertebrates.

Complement system

The complement system gets activated when complement binds to antibodies that have attached to microbes or to carbohydrates on the surfaces of microbes.

This recognition signal triggers a rapid killing response.

After complement proteins initially bind to the microbe, they activate their protease activity, which in turn activates other complement proteases, and so on. This produces a catalytic cascade that amplifies the initial signal by controlled positive feedback.

The cascade results in peptide production that attracts immune cells, increases vascular permeability and coats the surface of the pathogen (opsonizes it), which marks it for destruction. Complement can also kill cells directly by disrupting their plasma membrane.

Cellular barriers

Leukocytes (white blood cells) act like independent, single-celled organisms and are the second arm of the innate immune system.

The innate leukocytes include the phagocytes (macrophages, neutrophils, and dendritic cells) mast cells, eosinophils, basophils and natural killer cells.

These cells identify and eliminate pathogens, either by attacking larger pathogens through contact or by engulfing and then killing microorganisms.

Innate cells also activate the adaptive immune system.