Presentation

An Immune
Response
16.6

16.6 In Question
What is your body’s nonspecific defense to a
pathogen? How about specific defense?

Blood

Nonspecific Defense

Two Types of White Blood Cells
• macrophages are large, amoeba-like cells which engulf
and disassemble pathogens
• lymphocytes are specialized to recognize foreign
substances, make antibodies, and give rise to memory
cells

Macrophage Cells

A Working Macrophage

Macrophage Engulfing Bacteria

Lymphocyte

Lymphocyte

Lymphocyte Destroying a Tumor Cell

Antigen
• a molecular structure on the surface of a cell or virus
which can be felt by a lymphocyte
• each type of cell has specific antigens which act as a
label for the cell

Antigens

Antibodies
• plasma proteins made by the lymphocytes to fight
specific antigens (antibody generators which are part of
a pathogen)
• these are made as they are needed (after the pathogen
has entered the body)

Antibodies

Memory Cells
• long-lived cells that remember what a pathogen looks
like if it should ever enter your body again, these cells
can make you immune (resistant to infection) to the
specific pathogen
• your memory cells can quickly create antibodies for
the pathogen upon a second infection, before any
symptoms of the pathogen can appear

Vaccination

Vaccination
• a vaccine is a weakened, killed, or modified pathogen
that is injected into your body to stimulate antibody
production and build memory cells without you showing
any symptoms of the disease

Results of Vaccination

Out
Which of the following cells can engulf a pathogen?
a. red blood cell
b. lymphocyte
c. macrophage
d. antigen
e. fibrin