BIO 311D 2nd Edition Lecture 29 Outline of Last Lecture I. How are circulatory systems organized?II. Evolution of the heart in vertebratesIII. Introduction to blood and lymphIV. In-class exercise: index card questions Outline of Current Lecture I. Index Questions- AnswersII. Blood and LymphIII. Lymphocyte specializationIV. Action of B and T cells Current LectureI. Index Questions1. RA-RV, LA-LVRA-V, LA-V2. Bind receptors on heart muscle, trigger contraction. Medulla 3. Bind receptors on sphincter muscles at capillary bed, cause relaxation II. Blood and LymphA. Platelets are specialized in clottinga. Release of platelets and clotting factorsb. Cascade of reactions c. Plasma proteins synthesized in liver and circulated in inactive form d. Prothrombin circulating in plasmae. Thrombin (catalyzes f g) f. Fibrinogen circulating in plasmag. Fibrin 1. Clotting factors catalyze this reaction: prothrombin (plasma protein) thrombin2. Thrombin catalyzes this reaction: Fibrinogen Fibrin B. All blood cells come from pluripotent stem cells in bone marrow. They differentiate into cells with specific functions. a. What specializations found in –1. Lymphocytes that secrete protein? – Produce immunoglobulins 2. Macrophages that engulf particles? – Lysosomes, amoeba shaped, move around 3. Red blood cells that carry O2? – Produce a lot of hemoglobin, no mitochondria (won’t use oxygen), no Golgi, a lot of ribosomes, lose nucleus III. Lymphocyte specialization A. Lymphatic system: another circulatory system, involved in defense B. Defense systemsa. Innate, non-specific (rapid response)1. Barriers (skin, mucous membrane, secretions)2. Internal inflammation (phagocytic cells, natural killer cells, antimicrobial proteins) b. Adaptive, not innate (slower response)1. Specific B and Y lymphocyte responses C. What happens when you get a splinter? – Inflammation a. Mast cells (non specific) produces histamine, release chemical signals, increase in interstitial fluid, phagocytic cells releaseb. Fluid helps wash away cellular debris, increase circulation (more fluid flow)c. Increase in temperature slows down bacterial growth D. PhagocytosisAction of B and T cellsA. Lymphocytes (B and T cells) are involved in specific, acquired defensea. B cells “humoral response” – fights antigen in fluidsb. T cells “cell-meditated response” – fights antigen in cells B. Specific Defensea. Antigenic determinants are small portions of antigens (specific, non self or altered-self substances). Antibodies react with antigenic determinants. Our bodies can make millions of different antibodies, each specific to a particular antigen. 1. Antigen binding site, specificity is at the tip of the Y – R groups and shape C. Structure of Ig (immunoglobulin) is four polypeptide chains a. Which of the following is NOT part of the innate inflammatory response?1. Phagocytosis2. Fluid accumulation 3. Release of chemical signals4. Antibody Secretion (specific immune response) D. Every lymphocyte becomes committed to produce only 1 immunoglobulin, by cutting and splicing its DNA, permanently deleting other segments of the antibody genes. There’s also mRNA splicing and lots of mutation E. You’ve specialized to be a B or T cella. You’ve committed to fighting one specific antigen and now have membrane receptors specialized to bind only that antigenb. Hanging out in lymph nodes and wait for antigen to show up F. B Cell activation a. Correct antigen binds to receptor, stimulates cell to divide. This is called clonal selectionb. Of the clone of cells, some become plasma cells and secrete antibodyc. Others become memory cells remain
View Full Document
Unlocking...