Immunity Flashcards
Name 4 anatomical and physiological barriers
- skin
- ciliary clearance
- low stomach pH
- lysozyme and saliva
What is the difference between non specific (innate) and adaptive (specific) immunity?
- We are born with non-specific immunity as it is innate and does not distinguish a potential threat from one another.
- adaptive immunity involves lymphocytes which are specific threats.
- defence against specific antigens is known as the immune response.
Where are lymphocytes found and where do they mature?
bone marrow and thymus gland
Where are monocytes and macrophages formed?
red bone marrow
Name 3 lymphatic organs that contain large numbers of lymphocytes
- thymus
- spleen
-lymoh nodes
What 3 things to lymphocytes respond to?
- foreign proteins
- invading pathogens- bacteria or viruses
- abnormal body cells- virus infected cells or cancer cells.
Name the 3 types of lymphocytes
- B cells
- T cells
- NK (natural killer cells)
Name the roles for each T cell:
1. Cyctoxic T cells
2. Helper T cells
3. Suppressor T cells
- directly attack foreign cells or virus-infected cells
- stimulate the activation of both T and B cells
- inhibit both T and B cells
Name 3 non-specific (innate) internal types of immunity
- phagocytic cells- ingest and destroy bacteria, cellular debris, denatured proteins and toxins.
- interferons- inhibit replication of viruses.
- compliment proteins- promote destruction of bacteria; enhance inflammatory response
Name an example of an external non-specific (innate) immunity for each structure:
1. Skin
2. Digestive Tract
3. Respiratory Tract
4. Genitourinary Tract
- Physical barrier to penetration, secrets lysosomes.
- High acidity of stomach- protection by normal bacteria population of colon.
- Secretion of mucus, movement of mucus by cilia; alveolar macrophages
- Acidity of urine, vaginal lactic acid.
How does innate immunity recognise bacteria?
- chemotaxis
- production of cytokines
- senses of cytokines produced
- antigens on bacteria
- bacteria cell wall is different to other cell walls
- ## neutrophils sense when bacteria enters the cell through the release of cytokines and they move to the area through chemotaxis.
Describe the process of phagocytosis b a neutrophil or macrophage
- Pseudopods- around bacteria, creating an extension of their cell wall
- extending their cell wall around the bacteria, creating pseudopods and surrounding bacteria to engulf.
- cellular ingestion of bacteria
-lysosomes release lysozymes to break down bacteria, in bacteria vessel formed by creating pseudopods
How does the temperature become raised in the hypothalamus?
Leukocytes attack bacteria, which produces endogenous pyrogen (cytokine), upsets and therefore raises temp.
What are interferons?
- A type of cytokines
- chemical messengers, that coordinate the defences against infections, interferons activated by lymphocytes and macrophages or virus-infected cells.
- normal cells exposed to interferon molecules respond by producing anti-viral proteins.
- they also stimulate NK cells and macrophages.
- non-specific, short-acting resistance to viral infection.
What are Mast cells?
small, mobile connective tissue cells, often found near blood vessels
Describe the process of inflammation
-when stimulated by mechanical stress or chemical changes in the local environment, mast cells release chemicals including heparin and histamines into the interstitial fluid.
- these chemicals begin the inflammation process.
- histamine makes capillaries more permeable and speeds up blood flow through the area.
- the combination of abnormal tissue conditions and chemicals released by mast cells stimulates local sensory neurons, producing pain sensations.
- increased blood flow reddness the area and raises local temperature, changes increase the rate of enzymatic reactions so will speed up phagocytosis
what is Cell-mediated immunity?
T cells provide a defence against abnormal cells and pathogens inside living cells.
What is antibody-mediated immunity/ humoral immunity?
B cells provide a defence against antigens and pathogens in body fluids.
What effects does inflammation have?
- injury is temporarily repaired, and additional pathogens are prevented from re-entering the wound.
- the spread of pathogens away from the injury is slowed.
How is oedema created in inflammation?
-increased blood flow to inflamed areas caused by vasodilation.
- increased permeability of capillary membrane fluid-fluid goes from capillary to space between cells (interstitial space).
- leaking of fluid into interstitial space- swelling and oedema.
What are eosinophils?
-weak phagocytes- White Blood Cells, that exhibit chemotaxis.
- they attack parasites
Name the 3 actions of eosinophils
- release hydrolytic enzymes from their granules, which are modified lysosomes.
-probably also by releasing highly reactive forms of oxygen that are especially lethal to parasites. - by releasing from the granules a highly larvicidal polypeptide called major basic protein.
what does an increased number of eosinophils in the blood suggest?
suggests a parasitic infection
What other cells are basophils similar to?
Why are they similar?
-mast cells
- They both circulate in the blood and located outside capillaries in the body.
- both release histamine and smaller amounts of bradykinin and serotonin.
- both coordinate inflammation by releasing these chemicals.
Why are mast cells and basophils important in some types of allergic reactions?
they are important as the type of antibody that causes allergic reactions IgE, has a special propensity to become attached to mast cells and basophils- release heparin.
Name the four types of T lymphocytes
-Helper T cells or inducer T cells
-cytotoxic T cells/ killer T cells
- suppressor T cells
- Memory T cells
When does adaptive immunity (specific) develop?
- when you have been exposed to a specific immunity.
- can be passive or active, whether artificial or natural.
When does active immunity begin?
- develops in response to antigen exposure
What occurs in active immunity?
- body responds to an antigen by making its own antibody.
-What is passive immunity?
-Name an example of natural acquired passive immunity
- produced by transferring antibodies to a person from some other source.
- transfer of maternal antibodies across the placenta or in breast milk.
What are the four properties of adaptive immunity?
- Memory
- versatility
- specificity
- tolerance
What happens in Cell-mediated immunity?
-phagocytes are activated when exposed to the antigen
- which activate T cells find the pathogens and attack them through phagocytosis or the release of chemical toxins= destruction of antigens.
- T cells provide defence against abnormal cells and pathogens inside living cells.
What occurs in Humoral/antibody-mediated immunity?
- B cells provide defence against antigens and pathogens in body fluids
- activated B cells give rise to cells to produce antibodies which bind to the antigen and attack the antigen.
What is hypersensitivity?
when someone’s immune system harms them rather than protects them.
Type 1 Hypersensitivty (1):
- Genetic predisposition for T helper cells to be more _________ to certain antigens.
- A person with nut allergy will have __ _____ that bind to a specific molecule on the nut making it an allergen.
- Antigen-presenting cells carry allergen molecules that migrate to ____ ______.
- hypersensitive
- T cells
- lymph nodes
Type 1 hypersensitivity (2):
- T helper cell that binds to the allergen molecule on the antigen-presenting cell will change into ___.
- Cytokines ___,___,___ help T helper cell change into TH2.
-IL4 will get B cells to undergo antibody-class switching, meaning that they stop producing IgM and produce ___ instead (which is specific to nut allergen)
- TH2 releases IL5 to stimulate the production and activation of eosinophils, which contain toxins that can harm cells.
- IgE specific antibodies attach themselves onto the surface of ___ ____.
- TH2
- IL4, IL5, IL10
- IgE
- mast cells
Type 1 hypersensitivity (3):
- 2nd exposure
- IgE antibodies on mast cells attach to antigen allergen- causing the mast cell to release _______, causing allergic reaction symptoms to occur.
- histamine binds to __ receptors on bronchi causing _____ muscle contraction = difficulty breathing.
- Also causes blood vessel dilation and ______ permeability of blood vessel walls means that more fluid leaks out into interstitial spaces= oedema and hives.
- histamine (pro-inflammatories)
- H1
