3.5 Immune system

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 3

Welcome- 3EH

• Enter the room quietly
• Take your seat
• Get you book, notebook, and a pen
• Wait quietly for the instructions in the next dia.

To do - 7 min (ZS)

Complete ex. 10 - HOW IT FITS TOGETHER — The living world

serpmedia.org

The assignment - in pairs

• During the next assignment you will be working in pairs.
• You may discuss the text and the questions with each other (While whispering). 
• To complete the assignment you have 15 min. 
• Read the comics  “On Guard—Germs vs. the Immune System” 
• Answer the questions in your notebook

Answer the questions in your notebook

Answers 

1. Examples of specialization by human cells in the comic could include: nerve cells, macrophage, neutrophils, dendritic cells, skin cells, red blood cells, fibroblast, and lymphocytes

2. Macrophages identify germs by checking cell membranes for molecules that germs would have.

 

Answers 

3. The macroscopic signs of inflammation are redness, heat, swelling, and pain. White blood cells like macrophages help trigger inflammation with chemical signals. When epithelial cells that make up blood vessels get those signals, they change their shape, widening the vessels to allow more

Answers 

4. Pus is made mostly of dead neutrophils.

5. Cells communicate using chemical signals. (Nerve cells also pass electrical signals along their membrane, so that would be an acceptable student answer; but although this comic doesn’t go into detail, even a nerve cell uses a chemical signal to tell the next nerve cell to initial its electrical signal.)

6. Two ways germs can do damage to the cells in people are using up their food and leaving unhealthy waste.

Answers 

7. Antibody molecules attach to germ surfaces. Antibodies can then interfere with germs’ functioning, make germs stick together, and encourage white blood cells to eat the germs faster.

8. The immune system takes molecules from the germs themselves (antigen), and chooses a lymphocyte that makes exactly the right antibody to attack that antigen. (An antigen-presenting white blood cell like a dendritic cell helps show antigen to lymphocytes.)

Answers 

9. It is important for the immune system to keep a lookout in all those places because the areas where macrophages are concentrated are exactly the places where stuff from outside the body (including stuff passing through the digestive system) is most likely to get into the body. These surfaces are where germs are most likely to attack

Today Goals 

• Can describe how antibodies protect against infection.
  
• Can describe how immunity is created.
  
• Can describe what happens in the event of an allergic reaction.

Foreign bodies

Substances that do not belong in our body : exogenous/foreign bodies

• Poisons
• Pathogens: bacteria, viruses, parasites
• Blood/organs from a donor

Antigens 

Substances that doesn't belong in the body

Antibodies

• White blood cells make antibodies
• Antibodies fit (like puzzle pieces) on antigens
• Each antigen has its own antibody
• Pathogens covered in antibodies are helpless, they die or are eaten by white blood cells.

Antibodies doing their job

ANTIGENS    &    ANTIBODIES

Proteins on the surface (= cell membrane) of cells. Important for recognition.

Proteins made by lymphocytes 

(= white blood cells) can stick to antigens to inactivate them. Antibodies can be found in blood plasma.

Immune reaction

Pathogens entering your body = Infection

White blood cells will fight the pathogens:

• Encapsulating (= eating) them 
• Making antibodies

A white blood cell eliminating a bacterium (Phagocytosis)

• Any given type of antibody can only attach itself to one type of antigen.
• Many different antibodies. 
• The antibodies being transported through the body via the blood

Lines of defence

Natural /Innate immunesystem

Innate immunesystem:

Parts of the immune system that are present from birth

Artificial immunity

1.  Otherwise known as vaccination.

2. You receive a dead or weakened pathogen via an injection. This is known as a vaccine.

3. Specific white blood cells make antibodies.

4. You get a little bit sick.

5. When the pathogen enters again, your bodies make antibodies immediately and in large amounts. 

6. You are immune and will not get sick. 

ACTIVE IMMUNISATION           PASSIVE IMMUNISATION

WHO PRODUCES THE ANTIBODIES?

Get the disease

- Make your own antibodies

--Make long term memory cells

Vaccination/immunisation

- Make your own antibodies

--Make long term memory cells

Placenta or breastfeeding

- Mother makes antibodies

--No long term memory cells

Serum (blood plasma containing antibodies)

- Antibodies from serum

--No long term memory cell

artificial

natural

Fill the gaps in the text:

__1__ are present on the surface of pathogens. As a response from B cells __2__ are produced to neutralise the __3__

1. 1 = antibodies 2 = antigens 3 = pathogens
2. 1 = antigens 2 = pathogens 3 = antibodies
3. 1 = pathogens 2 = antigens 3 = antibodies
4. 1 = antigens 2 = antibodies 3 = antigens

vaccine 

Vaccine = fluid containing dead or weakened pathogens

The amount of antibodies in the blood after infection with the same pathogen

Anaphylactic response

• Severe allergic reaction
• Leads to swollen mucous membranes, thick lips, red blotches shortness of breath
• Blood vessels can dilate (expand) and blood pressure drops
• dangerous or fatal if not treated
• EpiPen - counteracts the anaphylactic response

Allergic reaction

• Exaggerated response against an otherwise harmless antigen (allergen)
• Common allergens: pollen, mites, nuts, shellfish etc.

Homework

• Complete this LessonUp
• Read basic 3.5 in the book 
• Complete the Assignments 1-4 , 6-9