Pathogens, Immunity & Inflammations

ByTemitope Olubode

Pathogens

DefinitionA pathogen is any organism that causes a

disease in another organism.

Types of Pathogens

Viruses- which cause chicken pox Bacteria- which cause food poisoningFungi - which cause ringworm, athlete’s foot,

and Oral thrush.

How Pathogens are spread

Contact with bodily fluids Ingesting undercooked food Swimming in contaminated water Personal contact thru Saliva, feces,

intercourse and unsanitary practices

Control of Pathogens

Pathogens can be controlled bySterilization- Complete removal of all

pathogensDisinfection- Inhibition of pathogens by

disinfectant Antisepsis -Inhibition of pathogens on living

surface by antisepticAntibiotic -An agent that is used to kill

pathogens inside the hostBody, (naturally produced by some microbes)

InflammationWhat is inflammation?

Inflammation is the body's basic response to injury.

Signs of inflammation

Inflammatory reactions are characterized by 5 distinct signPain- due to chemical released by damaged

cellsEdema- due to influx of fluid into damaged

regionRedness- due to expansion of the blood vesselsHeat- due to increase in blood flowImperative function- due to increased swelling

and pain

Stages of inflammatory reaction

Tissue injury- Damage that occurs during trauma

Release of Chemicals – Histamine Prostrogladins , Kinins

Leukocyte migration- Macrophages and Neutrophils- They neutralize and engulf harmful bacteria and ingest them

Tissue healing

Collagenation- Wound healing, Occurs toward inflammatory process

Revascularization- Damaged area forms new capillaries for blood in the region

Proliferation- Which lasts up to 4 weeksRemodeling - New cell mould to produce a

functioning tissue

ImmunityWhat is immunity?

Immunity - protection from disease and especially infectious disease.

Cells and molecules involved in such protection constitute the immune system

The response to introduction of a foreign agent is known as the immune response.

Types of immunityInnate or natural immunity- Made up of

several componentsPhysical barriers are the first line of defense

against infection. E.g. The skin and mucous membranes

Physiological factors- such as pH, temperature and oxygen tension limit microbial growth

Protein secretions such as lysozyme also help resist microbial invasion.

Molecules such a C-reactive protein are of considerable importance in protection against infection.

Types of ImmunityAdaptive or acquired Immunity-

Develops to meet the specific needs brought about by an individual’s circumstances.

Constantly evolves its capacity to defend the body against pathogens.

Strengthened as a result of exposure to diseases

Vaccinations also facilitate the adaptive system’s efficiency

Leukocytes, commonly known as WBC are the dedicated agents of acquired immunity

Types of ImmunityAdaptive immune system can be broken

down into two components:Humoral immunity- involves the production

of immunoglobins (antibodies) by B cells in response to bacteria and viruses.

Cell-mediated immunity- involves the production of immunoglobins by T cells in response to virus-infected cells.

Referenceshttp://www.cartage.org.lb/en/themes/

sciences/lifescience/generalbiology/Immunology/ImmuneSystem/OrgansCells/WhatisImmunity/WhatisImmunity.htm

en.wikipedia.org/wiki/Inflammationen.wikipedia.org/wiki/Pathogen