BIOL 320 1 st Edition Lecture 11 Outline of Last Lecture I Regulation of MAP II Extrinsic Factors Affecting BP III Homeostatic Imbalances for BP Hypotension Hypertension IV Circulatory Shock Definition Result Types V Vascular Disorders Atherosclerosis Arteriosclerosis VI Developmental Aspects Formed from Fetal Shunts Umbilical Veins Arteries Vessel Formation Aging I Lymphatic System a Functions b Lymph Fluid Formation c Volume II Lymphatic Vessels a Lymph Capillaries b Endothelial Lining c Collects d Collecting Vessels III Lymphatic Drainage a Pathway b Transport IV Lymphatic Collecting Vessels a Characteristics b Transport c Acquire Nutrients V Lymph Transport REVIEW VI Lymphoid Cells a Macrophages b Lymphocytes i Functions ii Types VII Lymphoid Tissues a Lymph Nodes i Regional Concentrations ii Function iii Primary Cell Type iv Characteristics Outline of Current Lecture VII Specific Lymphoid Tissues VIII Lymphatic Pathology IX Developmental Aspects of Lymphatic System I II Immune System a Functions b Innate Defenses c Adaptive Defenses Surface Barriers Current Lecture Specific Lymphoid Tissues Peyer s Patches o Location ilium part of small intestine o Function destroy pathogen that has managed to breech intestinal wall Spleen o Location next to stomach o Function RBC destruction recycling platelets storage and release home for numerous lymphocytes Fe stored for recycling RBCs Thymus o Location inferior to larynx by near lungs o Function produces hormones that mature T lymphocytes largest in kids shrinks atrophies with age Tonsils Waldeyer s Ring o Location palatine adenoid lingual o Function filter throat area MALT mucosa associated lymphatic tissue Peyer s patches tonsils appendix nodules in bronchiole wall Lymphatic Pathology Edema swelling atypical accumulation of fluid Elephantiasis o Cause results from filariae parasite invading lymph nodes from extremities o Result lymph vessels blocked dismantled swelling of lower extremities Lymphoma cancer of lymphatic system o Hodgkin s Characteristic giant B cells Reed Steinburg Symptoms swollen non painful lymph nodes fatigue persistent fever night sweat Treatment radiation Cure rate high If you have had mono more susceptible o Non Hodgkin s all other cancers of lymphoid tissues metastasis of undifferentiated lymphocyte Symptoms swollen nodes spleen Peyer s patches High grade Target young people Treatment 50 remission with chemo Low grade Target elderly Treatment not really responding Developmental Aspects of Lymphatic System 5th week beginnings of lymphatic system Origin not thymus mesoderm Thymus origin endoderm out pocketing growth of pharynx At Birth poorly developed except spleen and tonsils Immune System Functions 1 Defensive system protect body from invasion 2 Repel pathogens 3 Immediately respond to exposure Innate Defenses born with always present don t develop with exposure to environment nonspecific defenses o A Surface Barriers 1st line of defense Skin stratified squamous epithelial keratinized resists weak acids bases bacterial enzymes toxins Mucous membrane wet line all body cavities open to exterior similar to protective function of skin Cilia trap inhaled particles in nostrils upper respiratory tract Secretions sweat mucous sebum acids saliva Specific Barriers o 1 Skin pH 3 5 inhospitable to microbes sebum contains anti microbe toxins o 2 Stomach pH 2 acid neutralizes bacteria protein digesting enzymes secreted o 3 Vagina low pH acids produced by normal bacterial flora WHY yeast infections pH becomes more neutral antibiotics yeast thrive Normal male secretions o 4 Tears enzymes with anti microbial properties o 5 Saliva anti bacterial microbial enzymes o 6 GI Tract Respiratory Tract foreign particles trapped on by cilia will be washed to GI tract by mucous where it will be broken down o B Internal Defenses 2nd line of defense o Foreign particles that get past surface barriers now face the internal defenses PHAGOCYTES such as 1 Macrophages monocytes that have left the bloodstream Fixed kept in specific area ex Kupffer cells in liver microglia in brain Free wander about body looking for problems ex skin alveoli 2 Neutrophils most abundant WBC become phagocytic when encounter pathogen release defensins which pierce pathogen membrane BUT kill selves in process unlike macrophages 3 Eosinophils weakly phagocytic important against parasites discharge contents of granules over prey 4 Mast cells most known for role in allergies phagocytize bacteria readily o In order for phagocytosis to occur adherence must occur somehow must stick to them to outside matrix o Events of Phagocytosis 1 Phagocyte adheres to pathogens or debris 2 Phagocyte forms pseudopods that eventually engulf the particles forming a phagosome 3 Lysosome fuses with phagocytic vesicle forming a phgolysosome 4 Lysosomal enzymes digest the particles leaving a residual body 5 Exocytosis of the vesicle removes indigestible and residual material o Terms of Phagocytosis Opsonization makes tasty coated with compliment protein and antibody making it easier for phagocytes to grab and eat coating foreign particles with mix of antibody complement protein makes handles for phagocytes to grab Adherence doesn t always work Ex pneumococcus difficult to grab carbohydrate capsule present o Natural Killer Cells NKCs police o Function induce apoptosis in tumor and virus infected cells o Cell type large granular lymphocytes NOT phagocytic attack cell membrane release perforins o Mechanism of Action 1 Non specific kill self virus infected other cells much less picky than lymphocytes 2 Does NOT require activation of adaptive immune system 3 Enhances inflammation via chemicals 4 Release perforins lyse offending cells o Inflammatory Response Trigger any kind of tissue damage trauma excessive temperatures chemical burns infection damaged tissue release chemicals inflammation Four cardinal signs heat redness swelling pain impairment of function Benefits 1 Prevents spread of damaging agents 2 Enhances tissue repair 3 Dispose of pathogens debris Adaptive Defenses 3rd line of defense against specific foreign substances take a bit longer to effect o o o o o A Antigens B Cells of Adaptive Immune System C Humoral Immune Response D Cell Mediated Immune Response E Homeostatic Imbalance