Human Defence System Flashcards
What does the human defence system do?
Protects itself against pathogens via non-specific defence systems and the immune systems
What are the non-specific defence systems?
Skin, nose, trachea/bronchi and stomach
How does the skin protect your body from pathogens?
It covers the majority of the body and is a physical barrier to pathogens
What happens if someone skin is wounded?
Platelets gather together at the side of the wound and form me scab to maintain a physical barrier
How does the nose prevent pathogens from entering? And how do they leave the nose
Hair and mucus act as a physical barrier and trap pathogens. Pathogens are removed when you sneeze or blow your nose.
How does the trachea/bronchi prevent pathogens from entering the body
They have goblet cells which produce mucus to trap pathogens. They are lined with ciliated cells that have tiny called cilia
What does Cilia do?
It wafts the mucus and pathogens upwards to the throat so it can be swallowed and sent to the stomach
How does the stomach help in the human defence system?
It contains acid that as a chemical barrier. Pathogens enter the stomach in food or mucus from the Trachea and get killed by highly acidic stomach acid (hydrochloric acid)
What does the immune system do to prevent pathogens?
Detects and kills pathogens that made it past the non-specific defences
What is phagocytosis?
It is a non-specific process where phagocytes engulf and digest pathogens sometimes helped by lymphocytes
How do lymphocytes help Faygo sites?
Lymphocytes produce antibodies that cause pathogens to clump together and make them easier to engulf
How do lymphocytes create antibodies?
Pathogens have specific molecules called antigens on their surface which can be detected by lymphocytes. Lymphocytes produce antibodies with a specific shape that enable them to bind to the antigens. This makes pathogens clump together to help phagocytes.
What are memory cells or what do they do?
Memory cells are lymphocytes that remain in the blood after infection. If the individual is infected with the same pathogen memory cells quickly produce the antibodies to destroy the pathogen before reproduces and starts causing cell damage and symptoms
What do lymphocytes also produce other than antibodies? What do they do ? How does it help?
Lymphocytes can also produce anti-toxins to neutralise toxic substances produced by the pathogen. This prevents cell and tissue damage.
