1. Starter 1. How does our body provide these conditions?
Micro-organisms (such as bacteria/fungi and viruses) require food, warmth, moist and well oxygenated conditions to grow best.
Come up with a 3 points to these questions;
1. How does our body provide these conditions?
2. Then how our body
protects us from being overrun

2. If we are such a good environment – why aren’t we over-run?
The human body is in many places an ideal environment for bacteria / viruses / fungi
The moisture content is high
It has a stable temperature
60% water
Value of 36.8±0.7 °C
Represents a large food resource
In our alimentary canal (mouth to anus) the food supply is constantly renewed
Oxygen- our circulatory system is very efficient with our lungs, heart and network of blood capillaries delivering large quantities of oxygen every where around the body
It is not surprising then that hundreds of species, and billions of individual bacteria are living in and on most of us most of the time.
If we are such a good environment – why aren’t we over-run?

3. The human body has 3 lines of defence ......
Non-specific physical barriers
Skin
Mucus membranes / cilia
Hairs / sneeze/cough reflexes
Non-specific chemical barriers
Acid in stomach
Sebaceous/sweat glands in skin lower pH
Tear/saliva contain lysozyme enzymes which digest pathogens
Inflammatory Response
Mast cells in connective tissue release histidine
Histidine causes vasodilation and capillary permeability which is swelling
Attracts phagocytes and lymphocytes by cytokines
Cytokines – chemical messengers
-Causes migration of phagocytes
Complement cascade which helps clotting of site
Antimicrobial proteins attracted
Phagocytosis
Phogocytes engulf and then lysosome
fuse with pathogen vacuole and then digest pathogens
Releases more cytokines
Natural Killer Cells
Virus/cancer cells primary targets
Pore in membrane, signal molecule
Signals switch on suicide genes
Vital DNA and protein not made
Apoptosis occurs

4. Big picture Immune system diseases Non specific immunity
Disease survival mechanisms
Physical & chemical barriers
Infectious Disease
Inflammatory
Transmission
Epidemiology
Non-specific Cellular response
Specific immunity
Vaccination
Public Health
Immunological surveillance
B cells
T cells
Clonal Selection theory
Big picture

5. Learning outcomes
Explain the role of lymphocytes, B cells and t cells in the immune system
Work in pairs and then share what you have learnt

6. feedback CLASS More working together; PAIR Pair working group work
Whole class collaboration
feedback
PAIR

7. Get into pairs!
One pair to research t cell and other pair to examine b cells.
each pair with an information card on their cell alongside a text book (p ).
You need to produce summary notes and a poster on the role of their given cell.

8. Review / plenary Get together with a pair researching the same cell.
Take a post stick
Now give some feedback;
2 positives and 1 improvement

9. Homework Be ready to teach next lesson ...