BIOL 252 1st Edition Lecture 13 Outline of Last Lecture I Relaxation II Muscle Strength III Tension in muscle fibers IV Length tension relationship V Poll Everywhere VI Whole Muscle Contractions VII Muscle Metabolism Outline of Current Lecture I Modes of ATP Synthesis During Exercise II Fatigue III Classes of Muscle Fibers IV Cardiac Muscle V Smooth Muscle VI Intercellular communication VII Principles of hormone communication VIII Classes of Hormones IX Hormone Receptors and effects X Endocrine disorders XI Hypothalamus and Pituitary Current Lecture XII Modes of ATP Synthesis During Exercise a At start 0 seconds i Aerobic respiration using oxygen held by myoglobin b In short time our heart lungs cardiovascular system lag behind i Move to phosphagen system ii Quick way to create ATP from ADP build up iii Does not last long 1 5 10 seconds c If we run out of oxygen and ability to use phosphagen system use glycolysis i Not as efficient 2 net ATP d Aerobic respiration supported by cardiopulmonary function once lungs cardiovascular system catches up 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 XIII XIV XV e Must consider what we ve lost i Used up elements of phosphagen system 1 Consume ADP ii From glycolysis consume glucose and glycogen iii Put cell in state of debt must put resources back iv Oxygen debt debt due to lack of oxygen 1 Extra O2 needed following exercise for 2 Replacing body s oxygen reserves 3 Replenishing phosphagen system 4 Oxidizing lactic acid converting it to glucose 5 Serving elevated metabolic rate Fatigue a Muscle fatigue progressive weakness and loss of contractility from prolonged use of the muscles b Causes i Glycogen depleted decrease ATP ii Decrease ATP reduces Na K pump activity iii Low pH from lactic acid and other metabolic processes iv Reduced ACh junctional fatigue v CNS fatigue Classes of Muscle Fibers a Type I i Slow twitch fibers slow to respond 1 Longer latency period ii Red fibers contain myoglobin iii Oxidative fibers prefer aerobic metabolism iv Slow red ox b Type II i Fast twitch quick to respond ii White fibers contain little myoglobin iii Glycolytic fibers optimized for glycolysis 1 Use glycolysis alone whereas the others don t 2 Need lots of glycogen giving white color iv Tend to be big increase in muscle size increase in glycogen Cardiac Muscle a Striated b Intercalated discs i To fill voids on end of one cell wavy edge ii On the other cell fills valleys interlocking iii Ions can flow from one cell to next and link cells AP can propagate to next cell iv Gap junctions unite cell membranes c Desmosomes XVI i Mechanical linkages between cells ii Without these one cell contracts and it tears away from neighbor d Cell membrane admits calcium i Dual source of calcium SR and extracellular fluid e Limited mitosis f Contains autorhythmic cells that produce APs i Pacemaker cells g ANS can adjust heart rate and strength h Very slow twitches no summation or tetanus Smooth Muscle a No visible striations b Dense bodies similar to Z discs c No T tubules d Calcium comes from extracellular fluid e Capable of mitosis and hyperplasia growth of tissue through cell production i Uterus enlargement Endocrine System XVII Intercellular communication a Gap junctions through cytoplasm b Neurotransmitters through synaptic clef c Paracrines through interstitial fluid to neighbors i If picked up by the blood HORMONE d Autocrines through interstitial fluid on itself XVIII Principles of hormone communication a Released by endocrine glands endocrine cells neuroendocrine glands b Picked up by blood c Travel throughout body d Diffuse out of capillaries e Stimulate target cells XIX Classes of Hormones a Steroid hormones i Derived from cholesterol ii Secreted by gonads and adrenal cortex b Monoamines biogenic amines i Derived from tyrosine and tryptophan ii Secreted by adrenal medulla pineal thyroid glands iii NE and epinephrine c Peptides and glycoproteins i Secreted by pituitary hypothalamus and others XX Hormone Receptors and effects a Target cells are those cells that have receptors for the hormone b Hydrophobic hormones XXI XXII i Steroid hormones and TH ii Require transport proteins iii Penetrate plasma membrane and bind intracellular receptors 1 Receptor is inside the cell 2 The hormone receptor go to nucleus iv Affect gene transcription 1 Turn on genes that were previously off or turn off what was on c Hydrophilic hormones i Do not require transport proteins ii Do not pass into cells iii Stimulate cells 2nd messengers iv Peptides and catecholamines 1 Hormone receptor binding activates G protein 2 G protein activates adenylate cyclase 3 Adenylate cyclase produces cAMP second messenger 4 cAMP activates protein kinases 5 Protein kinases phosphorylate enzymes activates some enzymes and deactivates others 6 Activated enzymes catalyze metabolic reactions w wide range of possible effects on the cell 7 Ultimately changes behavior of target cell v Other second messengers besides cAMP vi How do hydrophobic hormones know which cells to enter Endocrine disorders a Abnormal signals w in endocrine system b Hyper hypo secretion c Hyper hypo sensitivity d How Tumors lesion autoimmune disorders Hypothalamus and Pituitary a Form floor and walls of third ventricle of the brain b Controls water balance thermoregulation sex drive childbirth and various autonomic functions c Many of its functions executed by pituitary gland d Nervous system structure tissue but also produces hormones e Anatomy of pituitary gland i Anterior lobe adenogypophysis adeno means epithelial 1 Arises from pharynx during development 2 Made of glandular epithelium ii Posterior lobe neurohypophysis 1 Outgrowth of brain 2 Nervous tissue 3 Makes NO HORMONES a Releases 2 b ADH and oxytocin 4 Neuro endocrine cells nervous tissue that produces hormones 5 ADH a Produced in hypothalamus b Transported by hypothalamo hypophyseal tract to posterior lobe c Diuretic causes you to make more urine d ADH produce less urine e Effects raise amount of water in your body f Two targets kidneys brain i Increase water retention increase thirst g Stimulants i High osmolality salt concentration h Under which conditions would cause elevated ADH levels i Extreme thirst ii Over hydration iii Drinking alcohol caffeine iv Hyponatremia sodium v Pituitary tumor