Blood 4 Flashcards
What is the function of the immune system?
- Protects from pathogens & foreign molecules (parasites, bacteria & viruses)
- Removes dead or damaged cells (particularly RBCs)
- Attempts to recognise & remove abnormal cells (inlc tumor cells)
What are the 2 types of body defences?
- Physical & chemical barriers
- Immune defences
What are the physical & chemical barriers the body has?
- Skin, epithelial linings & cilia
- Acids, mucous & lysozomes
What are the immune defences the body has?
- Innate, non-specific, immediate response
- Acquired: attack a specific pathogen (antigen)
What are the stages of response to a pathogen?
1 - Detect & identify foreign invader
2 - Communicate, alarm & recruit immune cells
3 - coordinate reponse among all pets
4 - Suppress or destroy invader
What is the lymphatic system made up of?
- Primary tissues
- Encapsulated tissues
- Lymph vessels
- Diffuse tissues
What are the primary tissues of the lymphatic system?
Bone marrow & thymus
What are the encapsulated tissues of the lymphatic system?
Lymph nodes & spleen
What is innate immunity?
Present from birth –> body’s nonspecific immune response to invasion
Name 6 cells of the immune system & the % of them found
- Basophils & mast cells = rare
- Neutrophils = 50-70%
- Eosinphils = 1-3%
- Monocytes & macrophages = 1-6%
- Lymphocytes & plasma cells = 20-35%
- Dendritic cells = NA
What is the primary function of the basophils & mast cells?
Release chemicals that mediate inflammation & allergic responses
What is the primary function of the neutrophils?
Ingest & destroy invaders
What is the primary function of eosinophils?
Destroy invaders, particularly antibody-coated parasites
What are the primary functions of monocytes & macrophages?
Ingest & destroy invaders
Antigen presentation
What is the primary function of lymphocytes & plasma cells?
Specific responses to invaders, including antibody production
What is the primary function of dendritic cells?
Recognise pathogens & activate other immune cells by antigen presentation
What is innate immunity also called?
Non specific immunity
What is innate immunity?
- Physical & chemical barriers
- Phagocytosis: macrophages, neutrophils, natural killer (NK) cells
- Engulf & digest “tagged” cells
- Inflammatory response
What are phagosomes?
Lysosomal enzymes digest pathogens that have been enclosed in phagosomes
What are the components of phagosomes?
- Lysosome contains enzymes & oxidants
- Phagosomes contains ingested pathogen
- & contains digested antigens
What are the stages of a macrophage engulfing an antigen?
- Macrophage engulfs antigen
- Macrophage digests antigen in lysosome
- Antigen-presenting macrophage displays antigen fragments on surface receptors
What are NK cells?
- Eliminate virus-infected & tumor cells
- Secrete inferons
- Interferon-gamma
What do the inferons that are secreted from NK cells do?
2 types secreted:
Inferon-alpha & inferon-beta
- Prevent viral replication
Interferon-gamma
- Activates macrophages & other immune cells
What is the role of the inflammatory response?
- Attract immune cells & chemical mediators to site of infection
- Produce physical barrier to prevent infection from spreading
- Promote tissue repair
What are the key players in the inflammatory response?
- Histamines from mast cells
- Interleukins
- Bradykinin = pain & swelling
- Complement cascade = membrane attack complex
What do histamines from mast cells do in the inflammatory response?
Swelling, edema & vasodilation
What do interleukins do in the inflammatory response?
Fever, blood vessels more permeable to white blood cells & proteins, acute-phase proteins
What is the action of the membrane attack complex?
- Complement proteins insert themselves into the membrane of pathogens, creating a pore
- Water & ions enter cell
- Cell swells & lyses
What is acquired immunity?
Sometimes called adaptive immunity –> directed at specific invaders & so is the boyd’s specific immune response
What are the 3 types cells in acquired immunity?
- T lymphocytes
- B lymphocytes
- NK cells
What are the types of T lymphocytes?
- Helper T cells
- Cytotoxic T cells
What are the types of B lymphocytes?
- Plasma cells
- Memory cells
What are naive B-lymphocytes?
Each cell in a lymphocyte clone has receptors specific to one antigen
What are the main things involved in humoral immunity (B lymphocytes)?
- Antibodies = immunoglobulins
- Plasma & memory cells
- Primary & secondary response
What is the primary immune response?
- Upon the first exposure to antigen, naive lymphocytes reproduce
- Clonal epansion
- Memory cells are long-lived & cont to reproduce
- Short-lived effector cells carry out the immediate response
What is the secondary immune response?
When memory cells are reexposed to the appropriate antigen, the clone expands more rapidly to produce additional effector & memory cells
How does memory change from the primary immune response to secondary?
In primary response the conc of atibodies is much lower, bc of memory the antibody conc in the secondary response is much higher
What are the 5 classes of plasma cells (antibodies)?
- IgG
- IgA
- IgE
- IgM
- IgD
What are the regions on antibodies?
- Light & heavy chain
- Fab region = fragement antigen binding
- Fc region = crystalisable region
Pls refer to the diagram of the antibody you may be asked to label it
Describe the structure of an antibody?
An antibpdy molecule is composed of 2 identical light chains & 2 identical heavy chains, linked by disulfide bonds
Where are each of the following antibodies found:
- IgG
- IgA
- IgE
- IgM
- IgD
- IgG = 75% of total plasma antibody
- IgA = Found in external secretions such as saliva, ters, intestinal, bronchial mucus & breast milk
- IgE = Plasma
- IgM = Plasma
- IgD = Surface of B-lymphocytes
What is the function of the following antibodies:
- IgG
- IgA
- IgE
- IgM
- IgD
- IgG = Activate Complement
- IgA = Disable pathogens before they reach the internal environment
- IgE = When mast cell receptors bind w IgEs & antigen, the mast cells degranulate & release chemical mediators such as histamine
- IgM = Activate Complement
- IgD
Name the functions of antibodies (6):
1 - Activate B lymphocytes
2 - Act as opsonins
3 - Causess antigen clumping & inactivation of bacterial toxins
4 - Activates antibody-dependent cellular activity
5 - Triggers mast cell degranulation
6 - Activates complement
What sort of repsonse are T lymphocytes involved in?
Cell-mediated response
What are T cells activated by?
Cell activated by antigen
(Major histocompatibly complex (MHC) attaches the antigne to the T cell)
What is the role of macrophages?
1 - Macrophage engulfs antigen
2 - Macrophage digests antigen in lysosome
3 - Antigen-presenting macrophage displays antigen fragments on surface receptors
How are T lymphocytes activated?
- Any nucleated cell binds to T lymphocyte (with antigen) to T cell receptor
- Signal transduction activates T lymphocyte
What is Major Histocomaptibility Complex (MHC)?
It incorporates antigen framents on the surface of a cell
What are the 2 classes of MHC & what are they?
- MHC class I = all nucleated cells
- MHC class II = macrophages/B lymphocytes & dendritic cells
Give an example of a of what binds to a class I and class II MHC cell:
- Class I = Cytotoxic T cells
- Class II = Helper T cells
What is an NK cell?
Natural Killer cell
How are NK cells activated & what do they kill?
T-cell precursors can either migrate to the thymus gland or branch off to form natural killer cells
These go on to kill antibody coated cells or MHC class I target cells
What happens when a T-cell precursor migrates to the thymus gland?
Form either:
- Cytotoxic T cells (these kill MHC class I target cells)
- Helper T cells (these bind to MHC-II antigen-presenting cells —> then secrete cytokines that activates other immune cells)
Look at the defenses against bacteria diagram
Had no idea how to get it onto a flashcard
Look at the defences against viruses diagram
Couldn’t get this onto a flashcard either
What are the 2 allergic responses?
- First exposure
- Re-exposure
What happens during first exposure in an allergic response?
- Sensitisation
- Activation, clone B cells, form antibodies & memory cells
What happens during re-exposure in an allergic response?
Many antibodies, activated T cells, intensified response, inflammation
Refer to the diagram of an allergic repsonse
Can’t get it on a flashcard
What are the 3 factors that affect blood type?
- Antigens on RBCs
- Antibodies in plasma
- Rh antigens & antibodies
What are the 4 types of antigens found on RBCs (determines blood type)?
- A
- B
- AB
- none (O)
What are the 3 types of antibodies you can have in plasma (determines blood type)?
- Anti A
- Anti B
- Anti AB
What are ABO blood groups?
A mixture of type O and type A blood
What happens when red blood cells with group A antigens on thier membranes aare mixed w plasma containing antibodies to group A?
The antibodies cause the blood cells to clump, or agglutinante
What are Rhesus antigens?
They are transmembrane proteins
Maternal immune system produces antibody against fetal blood
What does an RhD factor produce in a mother vs baby?
- RhD negative mother
- RhD positive baby
Give some examples of autoimmune diseases;
- Graves’ disease (hyperthyroidism) = thyroid-stimulating hormone receptor on thyroid cells
- Insulin-dependent diabetes mellitus = pancreatic beta cell antigens
- MS = myelin of CNS neurones
- Myasthenia gravis = ACh receptor of motor endplate
- Rheumatoid arhtiritis = collagen
- Systemic lupus erythematosus = intracellular nucleic acid protein complexes (antinuclear antibodies)
- Guillan-Barre syndrome = myelin of peripheral nerves
Refer to the neuro-endocrine-immune interaction
Couldn’t get this on a flashcard
Summary of lecture:
- Two primary lines of defence
- Diversity of pathogens
- Immune response = innate & required
- Lymphatic & circulatory systems
- Leukocytes & lymphocyes
- Inflammation & allergies
- Interactions between systems
