December Exam Review Notes 6

9 Pages
Unlock Document

Anatomy and Cell Biology
Anatomy and Cell Biology 3309
Kem Rogers

 Deep blue cytoplasm (because of ribosomes)  Nucleoli have disappeared  Chromatin has started to condense o Polychromatophilic erythroblast  Pink (eosinophilic) patches in cytoplasm due to collection of haemoglobin  Still has basophilic staining because of ribosomes  This is the last stage at which division occurs o Normoblast  Pyknotic nucleus (chromatin is fully condensed)  Pink cytoplasm due to haemoglobin  Still has a FEW organelles  Does NOT divide!! (because of condensed nucleus) o Reticulocyte  Forms upon the extrusion of the nucleus  Some ribosomes are present, therefore, can have a slight blue tinge o Erythrocyte  Mature RBC  Lasts in bloodstream for approx. 120 days  Erythropoietin (EPO) stimulates erythrocyte production near the committed stem cell stage o It is produced by the kidneys in response to low O2 levels o An increase in the number of RBCs in the bloodstream means more O2 can be carried  Blood doping refers to the process where you take out your own blood/someone else’s blood and store it o You then add it back before competition to increase RBC count to carry more O2  Anemias o Microcytic (small cell)  Low iron results in small, pale cells (due to lack of haemoglobin)  These cells are termed hypochromic, because they are below the normal level of colour o Megaloblastic anemia  There is low B12, folate, or intrinsic factor (which is used in binding B12)  It results in slowed proliferation and large, fragile cells  These cells still have a lack of haemoglobin  Megakaryocytes have a polyploidy, continuous nucleus o They are always found adjacent to sinusoids, which are capillaries with large lumens o They dump platelets into sinusoids  There are 2 types of bone marrow: o Red (blood-producing)  This still has adipocytes o Yellow/white (adipose tissue)  Only mature cells are released from bone marrow and into the bloodstream  In a light micrograph, cresyl violet can be used to distinguish between reticulocytes and erythrocytes o This is because it labels fragments of organelles left behind after enucleation  The presence of reticulocytes in blood means something is wrong o For example, in blood doping with EPO, too many cells can be produced and released prematurely as reticulocytes o In massive haemorrhaging, we can find reticulocytes in blood because they CAN carry oxygen  Recall that primary granules are azurophilic granules o These are found in all granulocytes o They are lysosomes containing myeloperoxidase (i.e. modified lysosomes)  Specific granules are specific to the type of granulocyte o These are secondary granules o They are NOT derived from primary granules o Neutrophils  These are bacteriocidal  Eg. Collagenase, phospholipase  These are involved in bacterial and fungal responses o Eosinophils  Antiparasitic/antihalmetic  Major basic protein, peroxidise, histaminases o Basophils  IgE sensitivity and anaphylaxis (i.e. allergic response)  Also contain chemicals that attract eosinophils, which also help modulate the allergic response  Heparin, histamine, heparin sulphate, leukotrienes  These leukocytes circulate in the blood, but then enter tissue to do their jobs  Granulocytic lineage o Myeloblast  3-5 prominent nucleoli (ribosome synthesis)  Basophilic cytoplasm  This is the first recognizable stage in granulopoiesis o Promyelocyte  1 or 2 nucleoli  Primary azurophilic granules (bright pink/magenta)  When these cells divide, they divide up their primary granules too  Since the proteins are packaged into granules, we can see negative golgi  We still don’t know which of the granulocytes will be formed o Myelocyte  Specific (secondary) granules appear  Nucleoli disappear because granules have already been made; no more ribosomes needed  The nucleus may have a SLIGHT indentation o Metamyelocyte  Definitely indented nucleus  From here, mature eosinophils and basophils form o Band neutrophil (ONLY FOR NEUTROPHIL)  Elongated, even, C-shaped nucleus  Since neutrophils have the greatest representation among the granulocytes in blood, we expect to see a lot of these in a smear  Megakaryocytes are huge polyploidy cells that underwent many nuclear divisions (upto 7) o There are only nuclear division, NOT cytoplasmic o They have pseudopods (projections) that project into sinuses (capillary with large lumen) o Platelets break off from these pseudopods  In platelets, we can see demarcation channels o These originally arise in pseudopods, where they are discontinuous perforations o When they join, that part of the cell breaks off o However, in platelets, we see residual demarcation channels that did not participate in the break  There are 2 divisions of the immune system: o Innate immune system  This includes the surface epithelium and protective mucus with bacteriocidal enzymes o Adaptive immune system  This involves different cells that become activated for an immune response (i.e. recognizing foreign antigens)  Lymph nodes filter lymph (i.e. tissue fluid)  Lymphatic vessels drain all tissue and return lymph to the circulatory system  There are 3 types of lymphocytes o T-cells  Cell-mediated immunity o Natural killer cells  Cell-mediated immunity o B-cells  Humoral immunity  In the lymphatic system, there are various supporting cells: o Reticular cells o Macrophages  These have an important role in engulfing foreign particles and presenting the antigen o Follicular dendritic cells o Langerhans’ cells (skin) o Epithelioreticular cells (thymus)  There are 2 primary lymphatic organs: o Bone marrow and thymus o These are the places where immature lymphocytes become “educated” (immunocompetent) and learn to identify foreign antigens (proteins)  Secondary lymphatic organs include: o Diffuse lymphatic tissue o Lymphatic nodules and nodes o Spleen  In the secondary lymphatic organs, immune cells are ALREADY immunocompetent o Instead, they are activated here and undergo subsequent expansion/proliferation  NK cells o These cells respond to various signalling proteins, which result in activation o Once activated, NK cells can release proteins  Perforins = these punch holes in cell membranes  Fragmentins = these disrupt DNA  T cells o There are various classes of T cells o Macrophages present antigens after engulfing pathogenic cells  This leads to the activation of a corresponding cytotoxic T cell, which proliferates o Activated cytotoxic T cells secrete perforins and fragmentins, which attack and kill target cells  The abovementioned cells are part of the body’s cell-mediated immunity  B cells are part of a cell’s humoral immunity o They produce antibodies o They become activated with help from helper T cells and other signals  This leads to expansion/proliferation o A mature B cell is known as a plasma cell, which can produce antibodies  Plasma cells have very basophilic cytoplasm  This is because they are full of ribosomes synthesizing proteins (Abs)  Therefore, we would also see negative golgi o Activated B cells produce memory cells, which are long-lived and remember the foreign antigen  Memory cells have varying lifespans  T and B cells come from the primary lymphatic organs: o Stem cells for B ce
More Less

Related notes for Anatomy and Cell Biology 3309

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.