immune system 2.0

•  Release of histamine from mast cells  is triggered by IgE 
• Histamine release from mast cells

  Triggered by IgE
• Perforins


  Part of the Tc action and put holes in target cell plasma membrane
• T cells


  Attack invaders directly, they provide help for antibody production by B cells
• Classes of antibody


  • IgG (most abundant in blood)
  • IgM (secreted first in primary immune response)
  • IgA (most abundant in secretions)
• Plasma cells


  Short lived cells that produce antibodies
• Secondary immune response to an antigen


  Faster than primary response because the infection is recognized by the memory cells
• Vaccines


  Protect against common childhood illnesses such as chicken pox, measles and mumps
• Antigen presenting cells (APCs)


  • Dendritic cells
  • B cells
  • Macrophages
• T lymphocyte activation


  T cells form in bone marrow and become immunocompetent in the thymus
• Suppressor T lymphocytes


  Down regulators involved in negative selection
• Cytokines


  Proteins that control the immune response, many are interleukins, many produced by genetic engineering and used as drugs
• Interleukins that activate T helper cells


  IL1 and IL2
• Monoclonal antibodies


  Antibodies made in vitro, produce an immortal cell line, fuse a specific B cell with a tumor cell, provide passive immunity as drugs
• Suppressor T cells inhibit the responses of other T cells and B cells
• Plasma cells


  Produce and secrete antibodies
• Cytotoxic T cells


  Cells that directly attack and use the TCR (T cell receptor)
• Activated B cell division produces daughter cells that become plasma cells and memory B cells
• Antibody action


  Promote inflammation through stimulation of antigens (by binding)
• Fetal antibody is uncommon because the developing fetus has an immature immune system
• IgE


  Mediates allergic reactions
• Antigen


  Foreign non-self molecule that mounts an immune response
• T cells form in bone marrow and become immunocompetent in the thymus
•  B cells form in bone marrow and mature in the bone marrow 
• Antibodies are produced and secreted by plasma cells.
• CD 4 cells: T- lymphocyte or helper T cells
• CD8 cell: Cytotoxic T cells
• Kidney


  • Functions: Fluid Balance, Homeostasis of ions, Balance pH (7.35-7.45), Excretion of N waste, Production of erythropoietin, Regulation of BP via angiotensin
  • Parts: Hilum, Minor and Major Calyx, Renal Cortex, Renal medulla, Renal Pelvis, Ureter, Renal Capsule, Renal Column
  • Blood supply: Aorta, Renal Artery, Segmental artery, Interlobar artery, Arcuate artery, Cortical radiate artery
• Nephron


  Functional units of the kidney
• Renal Corpuscle


  • Glomerular/Bowman's Capsule, Glomerulus
• Renal Tubules


  Proximal Convoluted Tubule, Loop of Henle, Distal Convoluted Tubule, Collecting Duct
• Types of Nephrons


  • Cortical Nephron, Juxtamedullary Nephron
• Juxtamedullary Nephron


  • Long Loop of Henle, Important for concentrating urine, Macula Densa, Granular cells
• GFR


  Amount of fluid entered from the glomerulus into the glomerular capsule
• Glomerular Filtrate


  Similar to plasma or interstitial fluid, Contains H2O, Glucose, AA, N wastes like ammonia, creatine, urea
• Factors influencing GFR


  Dilate afferent arteriole increases GFR, Constrict afferent arteriole decreases GFR, Constrict efferent arteriole increases GFR, Dilate efferent arteriole decreases GFR, Dehydration decreases GFR, Hypertension increases GFR, Hypotension decreases GFR
• GFR Regulation


  1. Intrinsic Control: Myogenic mechanism, Tubuloglomerular feedback

  2. Extrinsic: Sympathetic NS/Adrenal, Renin/Angiotensin Mechanism, Atrial Natriuretic Peptide
• Tubular Reabsorption


  • Transepithelial/transcellular via diffusion, active transport and osmosis, Paracellular through leaky tight junctions
• Tubular Reabsorption


  1. PCT: Reabsorption of Na, H2O, Nutrients, Cations, Anions

  2. Loop of Henle, DCT, Collecting Duct: Reabsorption of Na, Ca, K, H2O
• Tubular Secretion


  Substances secreted from peritubular capillaries into renal tubules via active transport, e.g. K, H+, HCO3