Cells and the Immune System Flashcards
What is immunology [1]
The study of the immune system
Name ways that the body prevents pathogens from entering? [3]
- Skin
- Enzyme in the tears
- HCl stomach acids
What is the non-specific response? [1]
Does not distinguish between pathogens and is instant
What is the specific immune response? [1]
Is the response to a particular pathogen which provides much longer lasting immunity
Explain how the skin is a physical barrier for pathogens? [2]
Constantly flaking so prevents pathogenic bacteria from colonising
What are phagocytes? [1]
White blood cells that travel in the blood which can engulf pathogens
What is the process by which phagocytes engulf pathogens called? [1]
Phagocytosis
Histamine produced at the site of an infection cause the blood vessels cause the blood vessels to dilate, why? [2]
Increase lumen therefore increase blood flow
So more WBCs can get to the area of infection
What is a toxin? [1]
A chemical released by a pathogen that can damage cells
Name the 4 types of pathogen [4]
- Bacteria
- Virus
- Fungus
- Protoctista
What are the two types of specific immune response? [1]
Cell Mediated and Humoral
What is an antigen? [1]
A foreign molecule usually a protein which can cause an immune response
What are the two types of lymphocyte? [2]
T cells
B cells
Describe the activation of a T-Cell? [3]
- Helper T cells receptors specific to the antigen (either presented on a macrophage or just in the blood)
- Helper T cell becomes active when they join
What does a T cell do once activated? [4]
- Alert cytotoxic T cells to area
- Release cytokines which stimulate the B cells specific to this antigen to clone and become plasma cells
- Stimulate macrophages to engulf pathogens by phagocytosis
- Develop into memory cells
What three things can activate a T cell? [3]
- Cancer cell displaying foreign antigens
- Macrophage
- Cell with a virus host
Where are B cells made? [1]
In the bone marrow
Why are B cells specific? [1]
Because each B cell has a unique receptor
Describe the activation of a B cell? [3]
1) Activated by the cytokines of an activated T-helper cell
2) Can engulf antigens through phagocytosis, they then display this antigen on the surface and wait for activation by a T-helper cell
Once activated what do B cells produce? [2]
- Memory B cells
- Plasma cells which can secrete antibodies
Describe the structure of an antibody [2]
Y shaped with a hinge region with two antigen binding sits at the end of each chain
What are antibodies made from? [1]
Proteins
What is a monoclonal antibody? [1]
An antibody grown from one single B cell
