Circul and Immune Bio 20 Flashcards
RBC/Erythrocytes
About 120 days, lack nucleus when matured, biconcave shaped. Large surface to volume ratio that helps in gas exchange. 250 mil hemoglobin. Very flexible.
Reticulocyte
Immature RBC (a day away from maturation), no nucleus, 1% of RBCs. During maturation they lose their ribosomes, mitochondria, and cytoplasmic enzymes and produce ATP by glycolysis.
What disposes of RBCs?
Macrophages of the spleen, bone marrow, and Liver Kupffer cells.
RBC stain
with Giemsa or Wright stain pinkish
WBC/ Leukocytes
Fight infection.
N,L,M,E,B
Neutro,Eosino,Basophils
Are granuloctyes. They contain specific granules in their cytoplasm which contains many types of enzymes. Lives only a few days
Lympho, Monocytes
Agranuocytes. Lacks those granules, can live from months to several years.
Diapedesis
Leukocytes leaving the bloodstream to go to connective tissue. The tissue is injured releasing chemical signals that cause vasodilation of capillary walls. Inflammation, defense reaction to invaders such as bacteria.
Inflammation
a) Redness: due to increased blood flow
b) Swelling: due to increase capillary permeability
c) Heat: due to more blood, bacterial products such as endotoxins
d) Pain: nociceptors are stimulated due to increased fluid pressure
e) Disturbed function
Neutrophils
Are first responders in acute bacterial infections. Very active as phagocytes. Most abundant.
Eosinophils
Destroying parasitic worms and participate in allergic reactions. Low phagocytic activity
Basophils
Least numerous WBC. Main job is to initiate the process of inflammation. Key in asthma, anaphylaxis, and hay fever. Produce histamine that induces inflammation (vasodilator) and heparin which prevents clotting.
Lymphocytes B
B lymphocytes: Humoral immunity: antibodies
B cells differentiate into plasma cells which make antibodies.
T Lymphocytes
T Natural Killer Cells: NK Cells secrete cytokines (peptides or glycoproteins that act on cells that have receptors for them).
T Helper Cells: Release cytokines as well as activate B cells to secrete antibodies and macrophage activation.
T Suppressor Cells: Regulation of both humoral and cell mediated responses.
Monocytes
Largest circulating blood cell. Differentiates into macrophages which have many lysosomes. They also produce cytokines that active inflammation.
Monocytes and macrophages are the same cell but in different stages of maturation.
Macrophages/monocytes other names
Liver: Kupffer cells Skin: Langerhans cells Bone: Osteoclasts CNS: Microglial cells Many golgi complexes and lysosomes. fuse to make foreign body giant cell.
Mast Cell
Produces histamine, heparin, and leukotrienes. Live a month months.
Main function is to store the mediators of the inflammation process.
Histamine
When released by mast cells, localized edema occurs and your mucosa swells. Breathing in difficult and you feel “stuffy”. Histamines open up or dilate capillaries and make the permeable. Increased diameter allows more clotting proteins and phagocytes delivered to injured area.
Leukotriene
Stimulates contraction of smooth muscle and enhances vascular permeability.
Derived from a hematopoietic stem cell.
Platelets/ Thrombocytes
Blood clotting, lives about 2 weeks, no nucleus.
Platelets combine with collagen to become activated. In a blood clot, fibrin aggregates into thin threads with RBC and WBC. This gelatinous structure is a thrombus.
Platelets come from megakaryocytes in the bone marrow.
Blood order of abundance
RBC > Platelets > WBC
Red Bone Marrow
Makes RBCs, WBCs, and platelets
Found in all bones, by age 15 or so it is confised to the axial skeleton ( skull, ribs, vertebral column)
Yellow Marrow
Appears as fat tissue and is seen in bones of the limbs.
At times of sever blood loss, yellow bone marrow can transform into red bone marrow to allow for more hematopoiesis.
Immunoglobins
A,E,D,G,M
Protein molecules that act as antibodies in our immune system. Antibodies are secreted by plasma cells.
IgG
Most abundant, longest half life. Only immunoglobin that can cross the placenta. Passive immunity protecting newborns against infections. Efficient at turning on the complement protein system, which aids the immune system.
IgM
Together is IgD, they are found on the surface of WBC to bind antigens to B cells. Primary responder.
IgA
Found in breast milk, tears, saliva, vaginal fluid, and mucous. Confers passive immunity to nursing infant.
IgD
Surface of B Cells and involved with cell differentiation and B cell activation.
IgE
Triggers mast cells and basophils to release histamine in allergies. Leukotrienes and heparin can be released.
Immunoglobin structure
2 light chains and 2 heavy chains.
Disulfide bonds link heavy chains together and link heavy and light chains together.
Opsonization
The coating the antibodies use to bind and directly present to a macrophage.
Epitope or antigenic determinant
Small area on an antigen that a receptor or antibody can bind.
Major Histocompatibility Complex (MHC)
Proteins that resides on the cell surface of most cells (not RBCs). Important for reactions in immunity, particularly in antigen presentation to T cells.
MHC Class I and II
Class I proteins: all cells except erythrocytes (8-12 aa length). Presents to cytotoxic T cells
Class II: macrophages, B- lymp, and dendritic cells; cells that are antigen presenting cells to the helper T cell (13-25 aa length). Presents to cytotoxic T cells and helper T cells
MHC process
A pathogen is captured by a cell and broken in antigen fragments. These fragmets bind to MHC molecule inside the cell. Class I protein forms a complex which is transported to the cell surface, exposing the peptides to the cell exterior. This combo of MHC and antigen is recognized by a T cell where 2 events can occur:
1) Cell is targeted for death
2) Immune system is activated
Active Immunity
a) You produce antibodies naturally after infection
b) Vaccine is administered which is able to elicit a protective immune response
Can be natural or be deliberate
Vaccine
Gives artificially acquire active immunity
Passive immunity
a) Antibody transfer from one person to another
b) Administration of serum or Igs to people with weak immuno systems
Passive immunization differs from Active
It does not reply on the host’s immune system to take charge but results from immediate availability of antibodies that be used to defend us against a pathogen.
Antivenin contains antibodies needed to neutralize the toxins, artificially acquired passive immunity.
Innate Immunity
Born with it, present and available at short notice.
Fever, interferon (protein made by body cells with numerous functions resisting viral infection), neutrophils, macrophages, and microglia.
Acquired Immunity
Works with the protection of the innate immune system.
Direct contact with the pathogen is immunity acquired.
Autoimmune Disease
Lupus, Hashimoto, Sjogren’s, MS, Rheumatoid Arthritis, DM1
Loss of self tolerance, in MS T cells destroy myelin sheath of many neurons in the CNS.
In rheymatoid arthritis, IgG molecules are locked up by an antibody and deposited on joint membrane. Deposits complex cause inflammation and pain.
Cancer organelle vs Normal organelle
Cancer cells: small cytoplasm, multiple nuclei and large nucleoli, course chromatin.
Normal cells: large cytoplasm, single nucleus and nucleolus, fine chromatin.
