Unit 4 - Non-Specific Defenses Flashcards
Name the two types of phagocytes…
- Neutrophil
* Macrophage (A mature Monocyte)
What do Cytokines do?
Cytokines are a type of signalling compound sent out which attract the cells involved in the immune response (Phagocytes, Compliment proteins e.t.c.).
Describe how mast cells activate the second line of defence…
When injured mast cells begin to release cytokines and histamine, which activate the second line of defence.
Describe the process of Phagocytosis…
When a phagocyte (A Neutrophil or Macrophage) engulfs a pathogen, surrounding it in a vesicle. Then the phagocyte releases lysosymes into the vesicle, digesting the pathogen.
What is the role of histamine?
Histamine causes vasodilation (stretching of the capillaries) and increased permeability if the capillaries (To let cells get out the bloodstream easier). This increases blood flow in the area.
How do Natural Killer cells combat against an Infection?
They release two enzymes: perforin, which causes pores to open on the target cell, and granzyme, which enters into the cell through these pores. Then the granzymes activate the cells self destruct pathways, causing the cell to self destruct, allowing easy phagocytosis. This process is know as Apoptosis.
What defences does the first line of the Non-Specific Defence have?
Chemical:
• Coughing and sneezing • Mucus and earwax
• Tears, sweat, stomach acid and saliva
Physical:
• Skin provides a barrier and blocks out pathogens, and is slightly acidic and provides an inhospitable environment for pathogens.
How does skin protect us from infection?
It acts as a physical barrier, blocking out pathogens. Also, the outer layer consists of dead cells, which are dry and provide a hostile environment for pathogens.
How is the second line of the Non-Specific line of defence triggered?
When the first line is breached (e.g. A cut) or you experience trauma.
What do blood clotting proteins do?
They go to the site of infection and begin to close up the wound using fibrin. This is known a Coagulation.
What is the role of compliment proteins?
They basically ‘complement’ the immune response, amplifying it and enhancing phagocytosis ( By attracting phagocytes and rupturing the membranes of microbes).
