Non-specific immunity: true or false?

Specific Response to Infection

• The Immune System

• Different kinds of Lymphocytes

• The Humoral Response (Part 1)

Key Terms: Lymphocytes, B Cells, T Cells, Immunoglobulins, Major Histocompatibility Complex

Phagocytosis

Phagocytosis

Specific immune responseThe specific or adaptive immune response can target a specific pathogen, although it is slower to act than the non-specific response.

the cellular or cell-mediated response involves highly-specialized cells that target pathogens inside cells.

the humoral or antibody-mediated response targets pathogens in body fluids with antibodies.

It features two main types of response to pathogens:

Lymphocytes

What are lymphocytes?Lymphocytes are a type of white blood cell (leucocyte) found in the blood and lymph nodes.

Collectively, lymphocytes can recognize millions of different antigens, due to the large variation of lymphocytes produced.

Lymphocytes recognise antigen molecules on the surface of pathogens, and co-ordinate the immune response against that pathogen.

LymphocytesB Cells

• Made in Bone Marrow• Travel in Blood and Lymph• Produce antibodies

(immunoglobulins)• Have membrane bound

receptors identical to the antibodies they produce called IgMs

• 100 Million types of B cells formed in developing embryo, all with different IgMs

T Cells• Made in Bone Marrow, but

mature in Thymus Gland• Display T Cell receptors on

their cell surface membrane.• 2 main types

T Helper cells – Stimulate the production of antibodies against antigens on pathogensT Killer Cells – Produce chemicals to destroy pathogens

Different types of lymphocytes

Humoral immune response

Effector mechanisms

Homework

1) Read and highlight White Blood Cells information sheet

2) Find out what is meant by the Major Histocompatibility Complex (MHC)