1. Lymphatic System and Immunity

2. b. Plasma membrane Cell wall Capsule: gel-like coating
Outside cell wall
Cell wall
Plasma
membrane
Flagellum b.

3. Bodies lines of defence
Non-specific
Specific

4. Lymphatic system Absorb excess tissue fluid Absorb fat in SI
Tonsil: patches of lymphatic tissue
Red bone marrow: site for the origin of all types of blood cells
Thymus: lymphatic tissue where T lymphocytes mature and
learn to tell “self” from “nonself”
Spleen: cleanses the blood
tissue
fluid
lymphatic
capillary
tissue cell
blood
Absorb excess tissue fluid
Absorb fat in SI
Lymphocytes and WBC
Body defence

5. Non-specific lines of defence

6. Specific lines of defence
bacterium
T cell
T-cell receptor (TCR)
Activation
Clonal expansion
Macrophage
Memory
Cytotoxic
Apoptosis
self
antigen
(MHCI)
cytokines

7. B Cells, clonal expansion, and antibodies
antigens
B cell
B-cell
receptor
(BCR)
a. Activation: When a B cell receptor binds to an antigen
activation occurs.
B Cells, clonal expansion, and antibodies
antigen
cytokines
from Helper T cells
b. Clonal expansion – During clonal expansion, cytokines secreted by
helper T cells stimulate B cells to clone mostly into plasma cells or memory cells.
Plasma cells
Memory B cells
c. Apoptosis – Apoptosis, or programmed cell death, occurs to plasma cells
left in the system after the infection has passed.
Apoptosis

8. Antibodies antigen-binding sites antigen Antigen binds
to binding site. V V V V
light
chain C C
Shape of antigen fits
shape of binding site. C C
heavy
chain
C = constant
V = variable

9. T Cells, clonal expansion, and antigen presenting cells
bacterium
T cell
T-cell receptor (TCR)
Activation
Clonal expansion
Macrophage
Memory
Cytotoxic
Apoptosis
self
antigen
(MHCI)
cytokines
T Cells, clonal expansion, and antigen presenting cells

10. T Cells and Cytotoxic T cells
Perforin
forms hole
in target cell.
Target cell
Granzymes
Enter through the
Hole and cause
Target cell to
Undergo apoptosis.
Cytotoxic T cell
perforin
vesicle
granzyme
T Cells and Cytotoxic T cells
SEM 1,250X
cytotoxic
T cell
target cell

11. Acquired Immunity
Non-specific defences