BIOL 320 1st EditionLecture 20Outline of Last Lecture I. Lipid MetabolismII. Plasma Cholesterol LevelsIII. CholesterolIV. Non-Dietary Factors Affecting CholesterolV. Interconversion Pathways of NutrientsVI. Absorptive StateVII. Insulin Control Absorptive StateVIII. Postabsorptive StateIX. Tissues/Organs Fuel UseX. Postabsorptive: Hormonal & Neural ControlXI. Liver MetabolismXII. Energy Balance & Body FatXIII. Regulation of Food IntakeOutline of Current Lecture XIV. Metabolic HormonesXV. Insulin EffectsXVI. Nutrient TimingXVII. Developmental AspectsI. Urinary SystemCurrent LectureMetabolic Hormones- Catabolico Glucagono Epinephrineo Cortisol- Anabolico Testosteroneo Growth hormoneo IGF-1o InsulinInsulin Effects- -Increases protein synthesis- -Increases amino acid transport- -Decreases protein degradation- -Increases glucose uptake- -Increases muscle glycogen storage- -Decreases cortisol release- -Increases muscle blood flowNutrient Timing- -Post-workout meal: Suzuki, et al. 1999o --Fed immediately vs. 4 hours post-exercise ---Fed immediately: 70% increase of fat oxidation enzymes & 24% decrease of abdominalfat- -Insulin spike: Esmarck 2001o --Carb/protein mix immediately vs. 2 hours post-exercise ---Carb/protein mix immediately: increase muscle growth 8% & increase muscle strength15% ---2 hours post-exercise: no growthDevelopmental 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 nutritiono --Diuretics (patients with CHF; hypertension) --> hypokalemiao --Antibiotics: can interfere with food absorptiono --Mineral oil: can interfere with absorption of fat-soluble vitaminso --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 stiffeningUrinary 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 ions3. Regulates volume & chemical composition of blood4. Maintains proper water/salt/acid/base balance- Secondary Renal Functions:1. Produces rennin (regulates blood pressure)2. Produces EPO (RBC production)3. Activates vitamin D4. Gluconeogenesis during prolonged fastingKidney- Three Layers: supportive tissues (innermost to outermost)o Renal capsule: fibrous capsule prevents infectiono Adipose capsule: fatty mass attaches & cushionso Renal fascia: dense fibrous connective tissue…function anchors- Internal Anatomy of Kidney1. Renal Cortex: lighter colored area; location of glomeruli2. Renal Medulla: darker-redo -Renal columns: extension of cortical tissue that separate the pyramidso -Pyramids: (cone-shaped) bundles of collecting tubules that drain in the papillaeo -Papillae: collection point that lead to calyces3. 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 themo -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 absorptiono –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 capillarieso –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