Immunology Part 7 Flashcards
What does the first line of defence include?
Skin, mucus, hair, cilia, tears, saliva, stomach acid
What happens to the immune system and body when something dies?
The immune system shuts down, and the body is invaded by bacteria, viruses and parasites within hours
What are all the external surfaces of your body?
Dead
What is the aim of the body ‘s first line of defence?
To prevent entry of pathogens and block the entry of all foreign particles
What is the skin?
The heaviest organ in the body, which weighs about 4.5KG, and exudes secretions
What are some examples of physical barriers?
Mucus and cilia
What are some examples of chemical barriers?
Skin, tears, saliva and stomach acid
What do tears and saliva contain?
Enzymes which destroy bacterial cell walls
What does mucus do?
Traps air borne particles that are breathed in
What does cilia in the lungs do?
Sweeps mucus towards the oesophagus for ingestion
What is a key feature of stomach acid and proteases and what do they do?
They have a pH of 1-2 and destroy proteins
Which cells produce mucus?
Cells lining the alimentary canal, respiratory tract and urogenital tract
What are some examples of tissue secretions?
Saliva, sweat, tears and stomach acid
When does the second line of defence come into play?
Once the first line has been bypassed and pathogens have gained access to human tissue
What does the second line of defence include?
Lymphatic system, phagocytes, inflammatory responses and fever
What are phagocytes?
Mobile, white blood cells that migrate from the blood vessels to the site of infection to engulf and destroy foreign particles
What is phagocytosis?
The engulfing and destroying of foreign particles, by using large vacuoles containing digestive enzymes
What may a large number of white blood cells in a human be due to?
Infectious diseases, inflammatory diseases or leukaemia
What is pus?
The remains of dead white blood cells that have engulfed to many bacterial cells, and contain cellular debris and living white blood cells
What are pimples?
Pores in the skin that have become clogged with dirt or bacteria
What is inflammation due to?
Histamines being released from cells that are invaded by pathogens or damaged
What do histamines do?
Increase blood flow to an area and therefore increase the number of white blood cells and other body repair cells
What is inflammation characterised by?
Red, hot, painful, swollen areas due to the increased blood flow
What can people take if inflammation results in too much pain?
Antihistamines to reduce the swelling
