Human Defence Systems Presentation PDF

Infection and Response Human Defence Systems  Learning Objective L To understand how the human body prevents and stops pathogen invasions. Success Criteria To describe non-specific human defence systems, and how the bo...

Infection and Response Human Defence Systems  Learning Objective L To understand how the human body prevents and stops pathogen invasions. Success Criteria To describe non-specific human defence systems, and how the body responds to vaccinations. To explain how white blood cells fight infection. To create a pictorial representation of how white blood cells fight pathogens. Non-Specific Defence Systems of the Human Body If there are numerous pathogens in the room all the time, why are we not continually ill? You have two minutes to discuss with a partner how the body defends itself from all these pathogens. Note down all of your ideas in your book. Talk to the pair next to you, do they have any different ideas? Non Specific Human Defence Systems Nose: Nasal hair keeps out Skin: The skin is a complete barrier dust and larger micro against pathogens (unless cut) and organisms. The production produces antimicrobial secretions. of mucus also helps trap pathogens. Trachea and Bronchi: Both of these produce Stomach: The mucus to catch stomach produces pathogens, and are hydrochloric acid to lined with cilia kill any pathogens (hairs). that may enter.  Complete the Table Below Body Defence Mechanism How It Stops Pathogens Nose Skin Trachea Bronchi Stomach  What Am I? I help protect the body from diseases and foreign invaders. I am made in the bone marrow. I have a nucleus. I am found in the blood. white blood cell White blood cells defend the body in three different ways: 1. phagocytosis; 2. producing antibodies; 3. producing antitoxins.  Phagocytosis Phagocytes are a type of white blood cell that engulf pathogens in the following way: 1. the phagocyte identifies a pathogen and attaches itself to it; 1. cytoplasm surrounds and engulfs pathogen; 1. the pathogen is killed and digested; 1. indigestible residue is removed. https://www.youtube.com/watch?v=438EovW4tzs Vídeo about phagocytosis  Storyboard Create a storyboard to illustrate what happens to pathogens in phagocytosis, for example: 1. The phagocyte identifies a pathogen and attaches itself to it. 2. Cytoplasm surrounds and engulfs pathogen. 3. Pathogen is killed and digested. 4. Indigestible residue is removed Key Terms engulf phagocytes cytoplasm  Antibodies 1. Pathogens contain antigens (unique molecules) on their surface. 1. When white blood cells detect these antigens, they produce antibodies (proteins) in response. 1. The antibodies lock onto the antigens, rendering them useless, whilst other white blood cells now destroy them. 1. Antibodies are specific to a particular pathogen and can be produced very quickly should the pathogen re-enter the body.  Storyboard Create a storyboard to illustrate how producing antibodies destroys pathogens. Hint – It may help to draw the antigens in one colour and the antibodies in another. Key Terms pathogen antigens antibodies specific  Antitoxins 1. Bacteria can produce toxins that are harmful to the human body. 1. White blood cells detect the toxins and produce antitoxins. 1. The antitoxins neutralise the effect of toxins.  Your task Create a storyboard to illustrate how producing antitoxins counteracts toxins produced by bacteria. Key Terms toxins antitoxins bacteria  Storyboard Examples Phagocytosis Antibodies Antitoxins  Assessment: Exam Style Questions 1. What are microorganisms that cause disease called? (1 mark) 1. White blood cells can defend the body in 3 different ways. They can produce antibodies, and what are the other 2 methods? (2 marks) 1. Explain how white blood cells provide immunity against a person getting the same disease twice. (2 marks)  Assessment: Exam Style Questions 1. pathogens 1. antibodies and phagocytes 1. White blood cells recognise the pathogen and can rapidly reproduce the antibody.  Vaccinations How many diseases have you been vaccinated against? rabies tetanus yellow fever diphtheria hepatitis B measles, mumps, rubella BCG (MMR) whooping cough meningitis HPV  How Do Vaccines Work? 1. A small amount of dead or inactive pathogen is injected into the body. 1. The pathogen has an antigen on its surface. 1. White blood cells detect the antigen as a foreign body. 1. White blood cells produce antibodies which lock onto the antigen destroying it. 1. Memory white blood cells are produced. 1. If the pathogen re-enters the body, the antibodies are mass produced very quickly, preventing re-infection.  How Do Vaccines Work? Complete the cut and stick sequencing activity to show how vaccinations work. Plenary: The Immune System Loop Cards Can you match the key word or phrase to link these cards?  Home Learning Produce a leaflet informing people of good hygiene practices in the kitchen.