Transcript L3&4 Lymphocytes

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
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
Represents a large food resource
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
Value of 36.8±0.7 °C
In our alimentary canal (mouth to anus)
the food supply is constantly renewed
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?
The human body has 3 lines of defence ......
Non-specific physical barriers
-Skin
-Mucus membranes / cilia
- Hairs / sneeze/cough reflexes
Inflammatory Response
-Mast cells in connective tissue
release histidine
-Histidine causes vasodilation and
capillary permeability which is
swelling
-Attracts phagocytes and
lymphocytes by cytokines
Phagocytosis
Phogocytes engulf and then
lysosome
fuse with pathogen vacuole and
then digest pathogens
Releases more cytokines
Non-specific chemical barriers
-Acid in stomach
-Sebaceous/sweat glands in skin
lower pH
-Tear/saliva contain lysozyme
enzymes which digest pathogens
Cytokines – chemical messengers
-Causes migration of phagocytes
-Complement cascade which helps
clotting of site
-Antimicrobial proteins attracted
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
Immune system
diseases
Non specific
immunity
Disease survival
mechanisms
Physical &
chemical barriers
Infectious
Disease
Inflammatory
Non-specific
Cellular response
Specific
immunity
Transmission
Epidemiology
Vaccination
Public Health
Immunological
surveillance
T cells
B cells
Clonal Selection
theory
BIG PICTURE
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
CLASS
FEEDBACK
MORE WORKING TOGETHER;
• PAIR WORKING
• GROUP WORK
• WHOLE CLASS
COLLABORATION
PAIR
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 (P321-325).
• YOU NEED TO PRODUCE SUMMARY NOTES AND
A POSTER ON THE ROLE OF THEIR GIVEN CELL.
REVIEW / PLENARY
• GET TOGETHER WITH A PAIR RESEARCHING
THE SAME CELL.
• TAKE A POST STICK
• NOW GIVE SOME FEEDBACK;
2 POSITIVES AND 1 IMPROVEMENT
HOMEWORK
BE READY TO TEACH NEXT LESSON ...