BIOL 252 1st Edition Lecture 17 Outline of Last Lecture I Lymphatic Organs II Nonspecific Defenses III Specific Defenses Outline of Current Lecture I B cells II Antigen presenting cells III Cellular immunity IV Humoral Immunity V Immunological Memory VI Forms of Immunity VII Heart Physiology VIII Cardiac Rhythm IX Pacemaker cells has unstable RMP X Comparison of Cardiac and Skeletal Muscle APs Current Lecture I II III B cells a Born in the bone marrow b Go to other places in the body skip the thymus entirely c Go through selection in the bone marrow d Do not have receptors have antibodies Antigen presenting cells a Can be any cell in your body b But there are professionals c Most common APCs macrophages dendritic cells B cells d Engulf bacterium break it apart antigen macromolecule is taken by MHC and presented on surface of the cell Cellular immunity a Tc antigen recognition clonal selection b Small population memory T cells c Majority of T cells that result from multiple rounds of mitosis more T c cells i All have ability to respond to same antigen ii Can find an enemy cell and deliver lethal hit These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute IV 1 Release perforins create holes 2 Release granzymes which enter target cell and result in apoptosis d TH cell has gone through selection process in thymus in same way i Make helper T cells for now memory T cells for later ii Secrete interleukins 1 Chemicals that attract white blood cells 2 Enhances immune system response do not kill any cells Humoral Immunity a B cells exposed to antigens b Each B ell has one type of antibody which is different than its neighbor s c B cells respond to antigen by taking it in and transfer to MHC put it on the surface d Needs helper T cell to recognize that it is foreign e Helper T cell recruited to flip the switch allowing B cell to respond f Clonal selection B cell divides repeatedly i Some become memory B cells ii Most become plasma cells 1 Pumps releases antibodies into the body 2 Antibodies when recognize antigen bind it 3 Antigen antibody complex a 1 Work in conjunction w complement activation of complement i Promotes inflammation lysis phagocytosis b 2 Neutralization c 3 Agglutination d 4 Precipitation e 2 4 inactivate i Result in phagocytosis 4 Antibodies a V Immunological Memory a Primary response i B cell is recognizes antigen ii Takes a long amount of time to elicit a response producing antibodies 1 Has to get permission from helper T cell 2 Making plasma and memory cells VI VII VIII b Secondary response i Body does not produce symptoms but still exposed to the virus ii What about a memory B cell allows this response to happen quickly 1 More memory B cells than original B cells 2 Become plasma cells Forms of Immunity a Active body produces antibodies in response to antigen b Passive body acquires antibodies c Natural no medical intervention d Artificial intentional transfer of substances that provide immunity e f Natural active natural exposure to antigens g Natural passive breastfeeding h Artificial active vaccination i Deactivated form of virus ii Does not hurt you gives you the symptoms because your body is actively fighting the antigen iii Gain memory cells so can have secondary response when exposed to the real virus i Artificial passive blood transfusions i Blood with antibodies ii Have high levels of antibodies following an infection 1 Donate blood antibodies to someone else iii Passive because immune system work but not on the basis of your own T or B cells Heart Physiology a Four chambers b Right and left atria right and left ventricles c Atria contract at same later and ventricles attract at same time after atria d Path of Blood i Double circuit a blood cell that leaves the heart goes through systemic circuit then pulmonary circuit before returning to heart ii Red oxygenated iii Blue deoxygenated iv In tissues lose blood as O2 goes to tissues v When goes to lungs oxygenated Cardiac Rhythm a In skeletal muscle electrical activity comes first b In heart same order electrical activity first c Right atrium specialized group of cells w in right atrium called the SA node i SA node cardiac muscle cells specialized as pacemakers ii Cardiac conduction system consists of specialized muscle cells do not contract essentially neurons IX X 1 Make sure heart is exposed to electrical impulses at right time d AV node cluster of conduction cells in ventricle e Bundle of His f Bundle branches run down the septum between ventricles interventricular septum g Purkinje fibers h SA node tells atria when to contract wave of AP down atria i Send signal all the way to Purkinje fibers ii Then start stimulating ventricles iii Ventricles contract from bottom up 1 If we wait until signal gets all the way to the bottom creates TIME DELAY Pacemaker cells has unstable RMP a A normal cell RMP 70 mV b A pacemaker cell has a bunch of channels sodium leak channels i Makes inside less negative sodium entering cell ii Causes steady incline of RMP depolarizes steadily iii Unstable situation 1 Depolarizes until threshold AP repolarization 2 Called a PACEMAKER POTENTIAL c Pacemaker physiology i SA node cells gradually depolarize from slow Na influx pacemaker potential ii Voltage regulated Ca and Na channels open at threshold iii Slope of pacemaker potential how much it is increasing over time 1 A higher slope higher frequency 2 Lower slope reduced rate of AP 3 To speed up the heart sympathetic NS a Through cAMP second messenger NE increases Ca permeability 4 To slow down the heart a Open up K channels from ACh released by parasympathetic nervous system b By allowing K to leak out offsets influx of positive Na Comparison of Cardiac and Skeletal Muscle APs a Cardiomyocytes have an extended plateau phase b c Long intermediate stage when membrane potential is neither depolarizing or repolarizing plateau phase i How does this work ii Depolarization result of opening of Na channels iii Repolarization K channels open iv Difference adding one channel 1 Allow Ca to trickle in at same time as K is trickling out stabilize 2 Important because Ca comes into cell a Prolonged contraction in cardiac muscle cells