THE HUMAN DEFENCE SYSTEM - LC BIOLOGY

IMMUNITY

THE ABILITY TO RESIST INFECTION

PATHOGEN

AN INFECTION CAUSING ORGANISM

GENERAL DEFENCE SYSTEM

ACTS AS A BARRIER TO ALL PATHOGENS ATTEMPTING TO GAIN ENTRY TO THE HUMAN BODY

SPECIFIC DEFENCE SYSTEM

ATTACKS PARTICULAR PATHOGENS IN A PARTICULAR WAY

ANTIGEN

A FOREIGN MOLECULE THAT STIMULATES THE PRODUCTION OF ANTIBODIES

ANTIBODY

A PROTEIN PRODUCED BY WHITE BLOOD CELLS IN RESPONSE TO AN ANTIGEN

INDUCED IMMUNITY

THE ABILITY TO RESIST DISEASE CAUSED BY SPECIFIC PATHOGENS BY THE PRODUCTION OF ANTIBODIES

ACTIVE IMMUNITY

INVOLVES THE PRODUCTION OF A PERSONS OWN ANTIBODIES IN RESPONSE TO ANTIGENS THAT ENTER THE BODY

NATURAL ACTIVE IMMUNITY

OCCURS WHEN A PATHOGEN ENTERS THE BODY IN A NORMAL WAY

ARTIFICIAL ACTIVE IMMUNITY

OCCURS WHEN A PATHOGEN IS MEDICALLY INTRODUCED INTO THE BODY

VACCINE

A NON-DISEASE CAUSING DOSE OF A PATHOGEN WHICH TRIGGERS THE PRODUCTION OF ANTIBODIES
MEMORY CELLS REMAIN IN THE BODY AND RECOGNISE THE ANTIGENS AND CAUSE THE PRODUCTION OF MANY ANTIBODIES VERY QUICKLY

IMMUNOLOGICAL MEMORY

Once infection is over memory lymphocytes remain. If the same antigen enters the body again lymphocytes recognise it.
The antibody is produced again quickly and in great numbers

PASSIVE IMMUNITY

OCCURS WHEN INDIVIDUALS ARE GIVEN ANTIBODIES THAT WERE FORMED BY ANOTHER ORGANISM

NATURAL PASSIVE IMMUNITY

WHEN A CHILD GETS ANTIBODIES FROM ITS MOTHER

ARTIFICIAL PASSIVE IMMUNITY

WHEN A PERSON IS GIVEN AN INJECTION CONTAINING ANTIBODIES MADE BY ANOTHER ORGANISM

B-CELLS

MATURE IN BONE MARROW
RECOGNISE THE ANTIGEN
PRODUCE ANTIBODIES
CONTROL MOSTLY BACTERIAL INFECTIONS

T-CELLS

MATURE IN THYMUS GLAND
Fight infection

HELPER T-CELLS

STIMULATE B-CELLS
RECOGNISE ANTIGENS
STIMULATE KILLER T-CELLS

KILLER T-CELLS

RECOGNISE ANTIGENS AND CAUSE ABNORMAL CELLS TO BURST BY PRODUCING PERFORIN

MEMORY T-CELLS

MEMORISE THE ANTIGEN
Stimulate b cell production

SUPPRESSOR T-CELLS

SWITCH OFF THE IMMUNE RESPONSE AFTER PATHOGENS HAVE BEEN DESTROYED

Elements of general defence system -first line of defence

Skin
Lysosomes
Mucous membranes
Cilia
Hydrochloric acid
Blood clotting

Elements of general defence system- second line of defence

Phagocytes
Inflammation
Fever
Interferon
Compliment proteins

First line functions

1.skin- waterproof physical barrier
2.lysosomes- antibacterial enzymes found in sweat tears and saliva
3.mucous membranes- in nose trachea and lungs produce a thick mucous which traps pathogens
4.cilia- tiny hairs which push mucous out the body
5.hydrochloric acid- in stomach kills pathogens
6.blood clots- stops pathogens from entering the body

Second line functions

1.phagocytes- white blood cells surround and destroy pathogens
2.inflammation- causes blood vessels to widen so more wbcs can come to the area
3.fever- prevents microorganisms from reproduction
4.interferon- chemicals that attack viruses
5.complement proteins- work with antibodies to cause cells to burst open

immunization

The protection against pathogens by vaccination or by injection of antibodies

what are monocytes

the largest white blood cells of the immune system. Monocytes protect us from bacteria, fungi and viruses.

What are macrophages

Recognise antigens, digest antigens, display antigen pattern which triggers immune response

What do plasma B cells do

produce antibodies