BIOL 320 1st Edition Lecture 20 Outline of Last Lecture I Lipid Metabolism II Plasma Cholesterol Levels III Cholesterol IV Non Dietary Factors Affecting Cholesterol V Interconversion Pathways of Nutrients VI Absorptive State VII Insulin Control Absorptive State VIII Postabsorptive State IX Tissues Organs Fuel Use X Postabsorptive Hormonal Neural Control XI Liver Metabolism XII Energy Balance Body Fat XIII Regulation of Food Intake Outline of Current Lecture XIV Metabolic Hormones XV Insulin Effects XVI Nutrient Timing XVII Developmental Aspects I Urinary System Current Lecture Metabolic Hormones Catabolic o Glucagon o Epinephrine o Cortisol Anabolic o Testosterone o Growth hormone o IGF 1 o Insulin Insulin Effects Increases protein synthesis Increases amino acid transport Decreases protein degradation Increases glucose uptake Increases muscle glycogen storage Decreases cortisol release Increases muscle blood flow Nutrient Timing Post workout meal Suzuki et al 1999 o Fed immediately vs 4 hours post exercise Fed immediately 70 increase of fat oxidation enzymes 24 decrease of abdominal fat Insulin spike Esmarck 2001 o Carb protein mix immediately vs 2 hours post exercise Carb protein mix immediately increase muscle growth 8 increase muscle strength 15 2 hours post exercise no growth Developmental Aspects Lack of protein during fetal growth 3 years can lead to mental deficits and learning disorders Metabolism problems in kids without genetic issues o Are rare except diabetes mellitus both I II types Metabolic rate decreases across lifespan Agents prescribed for age related medical problems influence nutrition o Diuretics patients with CHF hypertension hypokalemia o Antibiotics can interfere with food absorption o Mineral oil can interfere with absorption of fat soluble vitamins o Excess alcohol consumption basic malabsorption contributes to vitamin mineral decencies deranged metabolism liver pancreatic damage Non enzymatic binding of glucose to protein leads to cataracts tissue stiffening Urinary System Major function of urinary system those of kidney the other organs serve to support the kidney Primary Renal Functions 1 Filter blood 200L day 2 Removes metabolic waste toxins excess ions 3 Regulates volume chemical composition of blood 4 Maintains proper water salt acid base balance Secondary Renal Functions 1 Produces rennin regulates blood pressure 2 Produces EPO RBC production 3 Activates vitamin D 4 Gluconeogenesis during prolonged fasting Kidney Three Layers supportive tissues innermost to outermost o Renal capsule fibrous capsule prevents infection o Adipose capsule fatty mass attaches cushions o Renal fascia dense fibrous connective tissue function anchors Internal Anatomy of Kidney 1 Renal Cortex lighter colored area location of glomeruli 2 Renal Medulla darker red o Renal columns extension of cortical tissue that separate the pyramids o Pyramids cone shaped bundles of collecting tubules that drain in the papillae o Papillae collection point that lead to calyces 3 Renal Pelvis o Minor major calyces lead to ureters Anatomy of the Nephron structural functional unit of kidney o Renal Corpuscle Glomerulus Glomerular epithelium fenestrated allow passage of solute rich protein free filtrate from blood into Bowman s capsule Bowman s capsule Parietal layer structural Visceral layer Podocytes support cells have foot processes with slits between them o Renal Tubule Proximal convoluted tubule PCT cuboidal with microvilli mitochondria Loop of Henle Thin segment simple squamous very permeable to water Thick segment cuboidal columnar permeable to NaCl Distal convoluted tubule DCT Principal cells cuboidal no microvilli Functions more in tubular secretion than absorption o Glomerular capillaries Afferent arteriole large diameter glomerulus efferent arteriole smaller diameter Arteriole are high resistance efferent resistance higher causes high blood pressure in glomerulus which aids formation of filtrate along entire length of glomerular capillaries o Peritubular capillaries Low pressure Adapted for absorption Arise from efferent arteriole Cling to renal tubules Empty into renal venous system Vasa recta long straight efferent arteriole of juxtamedullary nephrons