420: PSIO Exercise and environmental physiology
- Glossary of important terms # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 27 28 29 30 31 32 33 Term or phrase Bioenergetics Adenosine triphosphate (ATP) Glucose Glycerol Exergonic reactions Endergonic reactions Law of mass action Q10 effect Energy systems Creatine phosphate (CP) Creatine kinase Adenylate kinase (aka myokinase) Adenosine monophosphate (AMP) Glycolysis Anaerobic metabolism Aerobic metabolism Metabolism (conceptual) Metabolism (functional) Direct calorimetry Indirect calorimetry (IC) VO2 VCO2 Respiratory quotient (RQ) Respiratory exchange ratio (RER) Non-metabolic CO2 Progressive-intensity exercise Constant-load exercise Energy Force Work Power Percent grade Brief definition Study of energy-exchanging reactions in living things High-energy compound formed via energy-yielding reactions as an energy source for cellular work Monosacchride, common metabolic substrate Carbohydrate (3-carbon) backbone of a triglyceride, gluconeogenic precursor Energy-releasing chemical reactions Energy-requiring chemical reactions States that the rate of a given chemical reaction is proportional to concentration of the reactants Doubling of reaction rates with a 10 C temperature increase A group of three processes (sets of reactions) used to resynthesize ATP High-energy compound that releases energy for ATP resynthesis, part of immediate energy system Enzyme catalyzing ATP resynthesis from breakdown of creatine phosphate Enzyme catalyzing ATP resynthesis from 2 ADP molecules, yields AMP, part of immediate energy system Product of ATP resynthesis in the adenylate kinase reaction, plays role in regulating CHO metabolism Anaerobic/cytosolic process converting a glucose molecule into 2 pyruvate molecules, yields 2 ATP Reactions that resynthesize ATP without the use of O2 (e.g. CP, glycolysis) A series of mitochondrial-based, oxygen-requiring reactions that result in resynthesis of ATP Sum total of all bioenergetic reactions in the body Rate of heat production by the body, conventionally expressed in kcal/min Measurement of heat via use of a calorimeter as a way to estimate metabolism Measurement of respiratory gas exchange as a means to estimate heat production, thus metabolism Measure of O2 consumption rate (typically determined via IC at the level of the lungs) Measure of CO2 production rate (typically determined via IC at the level of the lungs) Ratio of CO2 produced to O2 consumed during mitochondrial respiration (thus, at the tissue level) Ratio of CO2 produced to O2 consumed as measured by IC (thus, VCO2/VO2 at the lung level) CO2 not from aerobic metabolism (originated from blood HCO3-), CO2 that allows RER > 1.0 Energy yielded from the aerobic metabolism of fat and CHO, expressed in kcal/L of O2 Protocol in which the workload increases in a graded fashion (e.g. treadmill stress test) Protocol in which workload is not changed during the course of the bout, steady state achieved Capacity to do work Product of mass x acceleration (with acceleration being due to gravity (9.8 m/s2)), expressed in newton Force applied through a distance (force x distance), commonly expressed in joule or kcal Work rate (work/time), commonly expressed in watt or kcal/min, indicates exercise intensity Expression of treadmill incline, sine of the incline angle (vertical rise / belt travel (hypotenuse)) Percentage of energy expended that appears as external work Ability of the neuromuscular unit to precisely and efficiently coordinate complex movements Technique of positioning oneself directly behind another athlete to improve (fluid-) aerodynamics Organic compound from which energy is derived via metabolism, roughly speaking fat, CHO, and protein Sugar unit (~glucose), can be individual (monosaccharide) or linked as a polymer (polysaccharide) NAD+ is a cellular coenzyme that commonly carries hydrogen atoms (electrons and protons) FAD is a cellular coenzyme that commonly carries hydrogen atoms (electrons and protons) Reaction in which one molecule loses electrons (oxidized) and another gains electrons (reduced) Insulin- and exercise- (Ca2+, AMP) responsive glucose transporter, requires translocation to sarcolemma Enzyme catalyzing the ATP-dependent phosphorylation of glucose upon cell entry Branched polymer of glucose (polysaccharide), storage form of carbohydrate mainly in muscle and liver Formation of glycogen from glucose-6-phosphate (monosaccharide unit) Enzyme catalyzing the formation of glycogen from glucose-6-phosphate (monosaccharide unit) Breakdown of glycogen into glucose-6-phosphate (monosaccharide unit) Enzyme catalyzing the breakdown of glycogen into glucose-6-phosphate (monosaccharide unit) Anaerobic/cytosolic process converting a glucose molecule into 2 pyruvate molecules, yields 2 ATP Enzyme catalyzing the ATP-dependent phosphorylation of fructose-6-phosphate, rate limiting Lect. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5
26 Caloric equivalent of O2
34 Mechanical efficiency 35 Biomechanical skill 36 Drafting 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Substrate Saccharide Nicotinamide adenine dinucleotide Flavin adenine dinucleotide Redox reaction GLUT 4 Hexokinase Glycogen Glycogenesis Glycogen synthase Glycogenolysis Glycogen phosphorylase Glycolysis Phosphofructokinase (PFK)
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 52 53 54 55 Term or phrase Phosphoglycerate kinase Pyruvate kinase Lactate dehydrogenase (LDH) Gluconeogenesis Brief definition Enzyme catalyzing both oxidation (yields NADH+H+) and phosphorylation (using Pi) of G3P Enzyme catalyzing phosphate transfer from 1,3-diphosphoglycerate (1,3-DPG) to reform ATP Enzyme catalyzing phosphate transfer from phosphoenolpyruvate to reform ATP Enzyme catalyzing reduction of pyruvate to form lactate (yields NAD+), has isoforms (LDHH, LDHM) Glucose synthesis from various precursors (e.g. glycerol, pyruvate, certain amino acids), largely in liver ~Ratio between ATP/ADP, low value indicates increased cell activity thus need for ATP resynthesis Reaction rates vary due to enzymatic regulation, some players are CEC, AMP, Ca2+, Pi, cAMP, hormones Effector molecules affect enzyme activity by binding to an enzyme's regulatory site (not catalytic site) Process of altering an enzyme's function by addition (via kinase) or removal (via phosphatase) of Pi Liver and muscle receptor type favored by epinephrine, stimulates glycogenolysis--inhibits its synthesis Membrane enzyme catalyzing cAMP formation, 2nd messenger for hormones (e.g. epinephrine, glucagon) Phosphorylating enzyme, product of cAMP stimulation, activates phosphorylase, de-activates synthase, Dephosphorylating enzyme, product of insulin stimulation, activates synthase, de-activates phosphorylase Occurrence of chronic (nearly daily) exercise bouts consisting of sustained activities (e.g. jogging) Percentage of cellular space occupied by mitochondria, increases with endurance training Occurrence of chronic (nearly daily) exercise bouts of maximal intensity and short duration Enzyme catalyzing pyruvate decarboxylation + oxidation (yields CO2, NADH+H+) forming acetyl-CoA Reactions in which CO2 is liberated, common in aerobic metabolism reactions Entry molecule of Krebs cycle, and common molecule in CHO, FAT, protein metabolism Vitamin B5-derived cofactor required in CHO & fat metabolism, functions to carry acetyl & acyl groups Main aerobic metabolism reactions, mitochondrial reactions oxidizing acetyl-CoA, yields NADH+H+ Krebs cycle intermediate (4-C) that binds acetyl-CoA forming citrate, participates in e- shuttle systems Krebs cycle intermediate (6-C), product of OAA + acetyl-CoA union, provides PFK feedback inhibition Krebs cycle intermediate, dehydrogenated to form OAA, participates in e- shuttle systems Enzyme that functions as rate limiting step in Krebs cycle, redox reaction yields NADH+H+ Mitochondrial membrane assembly joining electron transfer with proton pumping + gradient generation Physophorylation of ADP to ATP in relation to ETC activity (oxidation), goal of aerobic metabolism Fast twitch fiber-predominant system, transfers H gained in glycolysis into mitochondria Slow twitch fiber-predominant system, transfers H gained in glycolysis into mitochondria Lect. 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 7 7 7 8 8 51 G3P dehydrogenase
56 Cellular energy charge (CEC) 57 Control of CHO metabolism 58 Allosteric modification 59 Covalent modification 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 Beta-adrenergic receptor Adenylate cyclase Protein kinase (PKA) Protein phosphatase-1 (PP-1) Endurance training Mitochondrial volume Sprint training Pyruvate dehydrogenase (PDH) Decarboxylation Acetyl-CoA Coenzyme A (CoA) (HSCoA) Krebs cycle Oxaloacetate (OAA) Citrate Malate Isocitrate dehydrogenase Electron transport chain (ETC) Oxidative Phosphorylation
78 Glycerol-phosphate e (H) shuttle 79 Malate-aspartate e (H) shuttle
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 Term or phrase Triglyceride (triacylglycerol) Free fatty acids (FFA) (fatty acyl) Bile emulsification Lipase Lipolysis Chylomicron Very-low-density lipoprotein Lipoprotein lipase (LPL) Fatty acid activation Esterification Glycerol phosphate Hormone-sensitive lipase (HSL) Albumin Fatty acid binding protein (surface) Fatty acid binding protein (cellular) Fatty acid translocase (FAT) Carnitine acyl-transferase I Carnitine Acyl-carnitine Carnitine translocase Carnitine acyl-transferase II Beta-oxidation Brief definition Principle ingested lipid, composed of glycerol (carbon backbone) and attached fatty acids (acyl groups) Non-esterified fatty acids (unassociated with a triglyceride or glycerol molecule, typically long-chained) Small intestine process of lowering lipid droplet surface tension by bile salts so dispersion occurs Enzyme catalyzing triglyceride breakdown (e.g. pancreatic, lipoprotein, hormone-sensitive) Process of triglyceride breakdown (hydrolysis) into glycerol and fatty acids, opposite of esterification Lipoprotein generated in intestinal epithelium from dietary lipid, transported to blood via lymphatics VLDL: liver product, transports triglycerides to adipose and muscle (maintains circulating lipid) Endothelial enzyme catalyzing lipolysis of circulating triglycerides (chylomicrons and VLDL's) Process of attaching a CoA to a fatty acid, required step for storage or oxidation at the cost of two ATP Process of building a triglyceride from glycerol phosphate and fatty-acyl CoA, opposite of lipolysis Form of glycerol used in esterification of fatty acids, product of DHAP hydrogenation Intracellular enzyme catalyzing lipolysis of stored triglycerides (adipose and muscle), has multiple stimuli Blood plasma fatty acid transport protein produced by the liver Membrane protein aiding fatty acid uptake across plasma membrane (FABPpm) (sacrolemmal-FABP) Aids intracellular fatty acid transport (e.g. muscle-FABP) Membrane-bound protein aiding in fatty acid transport, may work in conjunction with surface FABPs Outer-mitochondrial membrane enzyme, catalyzes acyl-carnitine formation (CAT I) Compound that helps transport fatty acids across the inner-mitochondrial membrane Fatty acid form during transport across inner-mitochondrial membrane, product of CAT I Inner mitochondrial protein shuttle that transports acyl-carnitine into and carnitine out of the matrix Inner-mitochondrial membrane enzyme, catalyzes acyl-carnitine dissociation (CAT II) Series of 4 mitochondrial reactions catabolizing acyl-CoA (round yields acetyl-CoA, NADH+H+, FADH2) Enzyme catalyzing esterification (transfer of acyl groups onto glycerol phosphate), stimulated by insulin Concentration of capillary blood vessels per unit of muscle Organic compound comprised of an amine (NH3+) and carboxyl group (COO-), protein building block Amino acids not synthesized by the body, must be obtained from the diet Equation relating dietary nitrogen (protein) intake versus nitrogen excretion Reaction in which the amine group (NH3+) of an amino acid is transferred to a keto analog Primary gluconeogenic amino acid, pyruvate amino analog released by skeletal muscle / taken up by liver Main skeletal muscle amino acid, involved in transamination with pyruvate, undergoes liver deamination Krebs cycle intermediate, keto analog of glutamate Mechanism aiding blood glucose homeostasis, released muscle alanine acts as gluconeogenic precursor Liver mitochondrial matrix process that removes amine group from amino acid and yields NADH+H+ Nitrogen metabolism by-product of liver, excreted by kidney, sweat glands also excrete Glycogen storage disease due to muscle glycogen phosphorylase deficiency Oxygen consumption expressed in L/min, indicative of metabolism (caloric energy expenditure) Oxygen consumption expressed in mL/kgmin, useful when comparing individuals of differing size Maximal capacity to consume O2, indicative of cardiorespiratory fitness when expressed in mL/kgmin Term for VO2max (e.g. aerobic or endurance capacity), can be an indicator of health or athletic potential Workload expression free of individual capacities (e.g. 50 watts of power, 1.5 L/min VO2, 7 mph velocity) Workload expression relative to an individual's maximal capacity (e.g. %VO2max, % of max power) Inadequate aerobic metabolism at start of exercise, anaerobic sources contribute to meet ATP demands Period during exercise that ATP needs are being meet exclusively by aerobic metabolism, constant VO2 O2 consumption elevated above resting levels after exercise, degree of which correlates with exercise dose Division of the nervous system that helps regulate involuntary body functions Autonomic nervous system division associated with the "fight or flight" response, opposes PNS Autonomic nervous system division associated with resting and digesting, opposes SNS Body system of ductless cells operating through hormones to help regulate body functions 70-100 mg/dl Class of chemical substances that includes the neurotransmitter norepinephrine and hormone epinephrine Lect. 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 10 10 10 10 10 10 10 10 11 11 11 11 11 11 11 11 11 11 11 12 12 12 12 12 12 12 12 12 13 13 13 13 13 13
102 Acyltransferase 103 Capillary density 104 Amino acid 105 Essential amino acids 106 Nitrogen balance 107 Transamination 108 109 110 111 112 113 114 115 116 117 118 119 120 Alanine Glutamate -ketoglutarate Glucose-alanine cycle Oxidative deamination Urea McArdle's syndrome Absolute VO2 Relative (mass-specific) VO2 VO2max Cardiorespiratory fitness Absolute exercise intensity Relative exercise intensity
121 Oxygen deficit 122 Steady state VO2 123 Excess post-exercise VO2 (EPOC) 124 125 126 127 128 129 Autonomic nervous system Sympathetic nervous system Parasympathetic nervous system Endocrine system Normal fasting blood glucose level Catecholamines
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 147 148 149 150 151 152 153 154 Term or phrase Norepinephrine (noradrenaline) Epinephrine (adrenaline) Insulin Glucagon Growth hormone Cortisol Circadian rhythm Motor unit Type I (slow twitch) muscle fiber Type IIa (intermediate) muscle fiber Type IIb (fast twitch) muscle fiber Myoglobin Myofibrillar (myosin) ATPase Low (light) exercise intensity Moderate exercise intensity High (heavy) exercise intensity Interval training Exercise training specificity Muscle memory Succinate dehydrogenase Mixed diet Low vs. high carbohydrate diet Glycogen supercompensation Exercise training taper Brief definition Catecholamine neurotransmitter of the SNS, comprises ~20% of adrenal medulla output Catecholamine hormone released by adrenal medulla upon SNS stimulation Pancreatic beta-cell peptide hormone that acts to lower blood glucose level by facilitating tissue uptake Pancreatic -cell peptide hormone that acts to increase blood glucose level by facilitating liver production Pituitary peptide hormone that aids fuel mobilization, levels increase during long duration exercise Adrenal cortex steroid hormone that aids fuel mobilization, levels increase during long duration exercise Innate daily fluctuation of behavioral and physiologic function, related to 24-hour day/night cycle Motor neuron and all the skeletal muscle fibers it innervates, fibers will be uniform in characteristics Muscle cell characterized by high oxidative capacity, fatigue resistance, and slow contractile speed Muscle cell characterized by having properties that fall between slow and fast twitch fibers Muscle cell characterized by high glycolytic capacity, high fatigability, and fast contractile speed Iron-containing intramuscular protein (structurally related to hemoglobin) that binds O2 Myosin enzyme that splits ATP allowing crossbridge action, different isoforms dictate contractile speed 35-50% VO2max (various paces of walking) 50-65% VO2max (brisk walking to light, conversational-pace jogging) 65-80% VO2max (jogging to running) Pertaining to the abdominal viscera (i.e. gut) Exercise session containing shorter segments of high intensity bouts interspersed with recovery periods Concept that specific muscles activated (and movements performed) adapt/benefit during exercise training Term referring to branch of brain memory related to motor functions (aka motor or procedural memory) Krebs cycle enzyme, its activity is often used as an index of aerobic capacity Diet with standard combination of energy nutrients represented (e.g. 55% CHO, 30% fat, 15% protein) Diets representing extremes in CHO intake (e.g. < 10% vs. > 70%) Process in which "carbohydrate loading" produces maximal glycogen storage within skeletal muscle Process of reducing exercise dose prior to competition in order to maximize recovery and performance Lect. 13 13 13 13 13 13 13 14 14 14 14 14 14 14 14 14 15 16 16 16 16 17 17 17 17
146 Splanchnic
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 Term or phrase Ventilation Respiration External respiration Internal respiration Cellular respiration Respiratory tree Conducting zone Dead space Respiratory zone Type I alveolar cell Type II alveolar cell Total cross-sectional area Respiratory membrane Lung elastic recoil (elastance) Surface tension Lung compliance Pulmonary surfactant Boyle's Law Atmospheric (barometric) pressure Pleural membranes Respiratory muscles Intra-alveolar pressure Intra-pleural pressure Tidal volume (VT) Basic flow law (Poiseuille's Law) Airflow (airway) resistance Asthma Pneumothorax Emphysema Pulmonary fibrosis Spirometry Total lung capacity (TLC) Residual volume (VR) Vital capacity Functional residual capacity (FRC) Pulmonary (minute) ventilation (VE) Alveolar ventilation (VA) Breathing frequency (FB) Hyperpnea Hyperventilation Ventilatory threshold Work (oxygen cost) of breathing Brief definition Movement of gases in and out of the lungs Biological process involving gas diffusion Diffusion of gases between alveolar air and pulmonary capillary blood Diffusion of gases between systemic capillary blood and body tissues Metabolic (aerobic) processes in which O2 is used and CO2 is produced within mitochondria Name given to progressively branched airways from trachea to alveoli due to tree form resemblance Airway space where gas diffusion cannot take place, airways dedicated to conducting air Air volume of the conducting zone Airway space where gas diffusion takes place, primarily composed of alveoli Simple squamous cell lining alveoli, are optimal for diffusion, comprise ~97% of alveolar epithelium Alveolar cells that produce surfactant, comprise ~3% of alveolar epithelium Sum of all surface area for a particular airway level, greatest in alveoli External respiration diffusion barrier comprised of alveolar epithelium, interstitium, capillary endothelium Resistance to deformation, property of structural elastic fibers and intra-alveolar liquid surface tension Force acting across a liquid surface as a result of intermolecular attraction that minimizes surface area Ease of deformation, stretchability, inverse of elastic recoil, expressed as volume / pleural pressure Phospholipid-protein product of type II alveolar cells that acts to reduce alveolar surface tension The pressure of a gas, at constant temperature, varies inversely with its volume (P1V1 = P2V2) Gas pressure exerted by air, ~700 and ~760 mm Hg in Tucson and at sea level, respectively Friction-reducing serous membranes that cover the lungs (visceral) and adjacent thorax surface (parietal) Muscles causing and/or aiding breathing (e.g. diaphragm), more aptly termed "muscles of ventilation" Pressure within the alveolar space, is negative relative to atmospheric pressure during inspiration Pressure within the pleural cavity, becomes more negative at higher lung volumes Amount of air inspired in a single breathe, ~500 ml/br at rest Law describing laminar flow in a tube, states that flow = pressure difference across tube / resistance Frictional force within middle airways that obstructs air flow, is primarily related to airway diameter Condition characterized by decreased airway diameter due to bronchospasm and/or airway inflammation Presence of air in the pleural cavity, results in a collapsed lung as pleural membranes lose fluid bond Condition resulting in loss of alveolar walls, increases compliance and lowers respiratory surface area Condition characterized by deposition of fibrous tissue in the lung, lowers compliance, restricts volume Lung function test measuring lung volumes as a function of time, can also indicate maximal flow rates Lung volume following maximal inspiration (maximal volume of air held by lungs) Volume of air remaining in lungs following a complete expiration Maximal volume of air that can be expired from a full inspiration, difference between TLC and RV Lung volume following normal expiration, balance between inward lung recoil outward and thorax recoil Volume of air expired per minute, product of tidal volume and breathing frequency, expressed in L/min Volume of air reaching the respiratory zone per minute, factors out dead space air from VE Number of breaths taken per min (aka respiratory rate) Increase in ventilation during exercise that is proportional to the increase in metabolic rate Increase in ventilation during exercise that is out of proportion (above) to the increase in metabolic rate Point during ventilatory response to exercise at which hyperventilation begins, occurs ~60-75%VO2max Kcals spent (O2 consumed) by respiratory muscles to move air, product of elastic and resistive components Effort of respiratory muscles in overcoming lung elastic recoil Effort of respiratory muscles in overcoming airflow (airway) resistance Each gas in a mixture of gases exerts a pressure proportional to its concentration in the mixture Pressure exerted by a gas in a mixture of gases, the product of total pressure and gas concentration PO2 is ~160 at sea-level (760 mm Hg x 21%) Partial pressure of water vapor in air, is 47 mm Hg in saturated (humid) air at body temperature ~150 mm Hg during normal sea-level breathing, lower than atmospheric PO2 due to PH2O PAO2 is ~100 mm Hg during normal sea-level breathing and hyperpnea, varies by ratio of VA/VO2 Lect. 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 18 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20
197 Elastic work of breathing 198 Resistive work of breathing 199 200 201 202 203 204 Dalton's Law Partial pressure Atmospheric O2 partial pressure Water vapor pressure (PH2O) Tracheal O2 partial pressure Alveolar O2 partial pressure
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # Term or phrase Brief definition PaO2 is ~90 mm Hg during normal sea-level breathing and hyperpnea, varies based on PAO2 PvO2 is ~40 mm Hg at rest, decreases during exercise as muscle PO2 decreases Lect. 20 20 205 Arterial O2 partial pressure 206 Venous O2 partial pressure 207 208 209 210 211 212 213 214 215 216 217 218 219 220 Venous (right-left) shunt Fick's law of diffusion Hypoventilation Pulmonary edema Transit time Henry's Law Solubility constant for O2 in blood Hemoglobin saturation Hemoglobin constant for O2 Hemoglobin concentration Anemia Oxy-hemoglobin dissociation curve Arterial O2 content Venous O2 content
Passage of blood to the arterial system without going through ventilated areas of the lung 20 Describes rate of gas diffusion as being related to surface area and pressure gradient over surface thickness 20 Ventilation rate that is less than what is appropriate for the metabolic rate 20 Condition characterized by fluid accumulation in the alveoli, often a result of increased pulmonary capillary pressure 20 Duration an RBC spends in a pulmonary capillary, is ~0.75 sec at rest and decreases during exercise 20 Volume of gas dissolved in a liquid is the product of the gas partial pressure and its solubility in the liquid Volume of O2 dissolved in blood per each mm Hg PO2 is 0.003 ml O2 Average level of O2 binding by hemoglobin, ranges from 0 - 100% Volume of O2 bound by hemoglobin when fully saturated = 1.34 ml O2 / g Hb Amount of hemoglobin per blood sample, ~15 g/dl in a healthy individual Condition of low O2 carrying capacity by blood as a result of a depressed hemoglobin concentration Figure describing hemoglobin saturation with O2 as a function of PO2, is affected by H+, PCO2, temp CaO2 is normally ~20 ml O2 / dl, which includes both the dissolved and hemoglobin bound components CvO2 is normally ~15 ml O2 / dl at rest and decreases during exercise due to tissue extraction 21 21 21 21 21 21 21 21 21 21 21 22 22 22 22 22 23 23 23 23 23 23 23 23 23 23 23 23 24 24 24 24 24 24 25 25 25 25 26 26 26 26 26
221 Cardiac output (Q) Rate at which blood is pumped out of the left ventricle into systemic circulation, expressed in L/min 222 Exercise-induced arterial hypoxemia Drop in PaO2 (and SaO2) as exercise intensity increases without known mechanism (aka EIAH) 223 224 225 226 227 Venous CO2 partial pressure Alveolar CO2 partial pressure Arterial CO2 partial pressure Total CO2 content in blood Carbonic anhydrase PvCO2 is ~45 mm Hg at rest, increases during exercise as muscle PCO2 increases PACO2 is ~40 mm Hg during normal sea-level breathing and hyperpnea, varies by ratio of VCO2/VA PaCO2 is ~40 mm Hg during normal sea-level breathing and hyperpnea, varies based on PACO2 Combined CO2 total from dissolved, protein bound, and HCO3- forms, a function of PCO2 and Hb sat RBC enzyme catalyzing the equilibration of dissolved CO2 and carbonic acid (CO2 + H20 H+ + HCO3-) Collection of neurons in the medulla oblongata that rhythmically activate the respiratory muscles Group of brainstem neurons sensitive to changes in PaCO2 (or more correctly in PCO2 of the CSF) Increase in ventilation in response to an increase in PaCO2, mediated by central chemoreceptors Cells of the carotid body sensitive primarily to changes in PaO2 but also to changes in H+ and K+ Small tissue knob at the bifurcation of common carotid artery that contain peripheral chemoreceptors Increase in ventilation in response to a decrease in PaO2, mediated by carotid body chemoreceptors Cranial nerve with sensory afferents from the carotid body chemoreceptors to respiratory center Most far reaching of the cranial nerves, provides afferent (sensory) feedback from lung receptors Feedforward signal originating from motor cortex to control ventilation in proportion to exercise intensity Receptors sensing length (muscle spindle) and tension (Golgi tendon organ) change (aka proprioceptors) Receptors that respond to increases in muscle metabolites (such as H+, K+, CO2, adenosine) Intrinsic neuronal property of increase in output (response) over time with constant input (stimulus) Test to measure largest volume of air that can be ventilated in 15 sec, expressed in L/min (aka MVV) Highest level of ventilation reached during maximal exercise, generally 25% less than MVV Ratio of ventilation to whole body oxygen consumption (VE/VO2)
228 Respiratory control center 229 Central chemoreceptors 230 Hypercapnic ventilatory response 231 Peripheral chemoreceptors 232 Carotid body 233 Hypoxic ventilatory response 234 235 236 237 238 239 Glossopharyngeal nerve (CN IX) Vagus nerve (CN X) Central command Muscle mechanoreceptors Muscle metaboreceptors Short-term potentiation
240 Maximal voluntary ventilation 241 Maximal ventilation (VEmax) 242 Ventilatory equivalent for O2
243 Respiratory muscle training Training respiratory muscles specifically via breathing maneuvers for increased endurance or strength 244 Max sustainable ventilatory capacity Index of respiratory muscle endurance, measure of ability to maintain simulated VEmax 245 Max inspiratory pressure generation Index of respiratory muscle strength, measure of negative pressure produced by a max inspiratory effort 246 247 248 249 250 251 252 253 254 Acclimatization Hematocrit Blood doping "Live high, train low" principle Obstructive lung disease Restrictive lung disease Asthma Airway responsiveness Airway sensitivity Functional compensation occurring over days or weeks in response to changes in the physical environment Fraction of blood sample occupied by RBCs, commonly 40% and 45% in females and males, respectively Process of artificially increasing RBC concentration in efforts to improve endurance performance Training scheme in which an athlete sleeps in a hypobaric setting while still training near sea-level Condition characterized by an increase in airflow resistance, diagnosed by low FEV1/FVC ratio Condition characterized by a low (restricted) lung volume, diagnosed by low FVC compared to predicted Condition characterized by decreased airway diameter due to bronchospasm and/or airway inflammation Degree of narrowing that an airway has to a given level of irritant stimulus Indicator of the minimal level of stimulus needed to elicit an airway-narrowing response
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 255 256 257 258 259 260 261 262 263 264 Term or phrase Bronchospasm Mast cell Forced vital capacity Forced expiratory volume in 1 sec Exercise-induced asthma Blood pH Metabolic acidosis Respiratory alkalosis Respiratory compensation Non-metabolic CO2 Brief definition Constriction of bronchiolar airway smooth muscle (aka bronchoconstriction) Widely distributed hemopoietic-related cell that releases inflammatory mediators FVC is the volume of air maximally expired following a maximal inspiration, can be predicted via height FEV1 is the volume of air expired during the first second of an FVC maneuver Airway obstruction produced during or relatively soon after exercise Tightly regulated at ~7.4 pH imbalance in which the blood has accumulated too much acid, can result from exercise metabolism pH imbalance characterized by a PaCO2 < 35 mm Hg, alkaline blood a result of hyperventilation Hyperventilation in efforts to increase pH (lower acidosis) by expiration of non-metabolic CO2 CO2 not from aerobic metabolism (originated from blood HCO3-), CO2 that allows RER > 1.0 Lect. 26 26 26 26 26 27 27 27 27 27
PSIO 420: Exercise and environmental physiology
- Glossary of important terms # 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 Term or phrase Intercalated disks Conduction system of the heart Sinoatrial (SA) node Atrioventricular (AV) node Myocardium Vasculature Arteriole (resistance vessels) Vascular tone Vasodilation Vasoconstriction Venodilation Venoconstriction Basic flow law (Poiseuille's Law) Cardiac output (Q) Mean arterial pressure (MAP) Systemic vascular resistance (SVR) Alpha-adrenergic receptor Metabolite-induced vasodilation Systole Diastole Cardiac cycle Stroke volume (SV) End-diastolic volume (EDV) End-systolic volume (ESV) Three determinants of SV Preload Afterload Contractility Venous return Frank-Starling principle Respiratory (intra-thoracic) pump Skeletal muscle pump Fick principle of VO2 Fick principle of whole body VO2 Heart rate (HR) Maximal heart rate (HRmax) Intrinsic heart rate Resting membrane potential Depolarization Hyperpolarization Neurotransmitter Beta-adrenergic receptor Acetylcholine Cholinergic receptor Vagal tone Anticholinergic agent Beta-blocker Blood perfusion (to perfuse) Brief definition Junctional region between two adjacent cardiac muscle cells, contain gap junctions for electrical conduction Specialized tissue circuit that sequentially depolarizes regions of the heart for a coordinated contraction Myocardial conduction tissue of the upper right atrial wall that acts as the heart pacemaker Myocardial conduction tissue in the inferior right atrial septum, only electrical connection of atria/ventricles Heart muscle tissue, is comprised of cardiac muscle cells--aka cardiomyocytes Blood vessels Microscopic blood vessels connecting arteries with capillaries, main site of blood flow resistance Relative degree of blood vessel smooth muscle activity Relaxation of arteriolar wall smooth muscle such that the lumen diameter increases Contraction of arteriolar wall smooth muscle such that the lumen diameter decreases Relaxation of venous wall smooth muscle such that the lumen diameter increases Contraction of vein wall smooth muscle such that the lumen diameter decreases Law describing laminar flow in a tube, states that flow = pressure difference across tube / resistance Rate at which blood is pumped out of the left ventricle into systemic circulation, expressed in L/min Average force exerted by blood onto inner artery walls, product of cardiac output and vascular resistance Sum total of systemic blood flow resistance in the vasculature (aka total peripheral resistance, TPR) Arteriolar (and venous) smooth muscle receptor type activated by norepinephrine, causes vasoconstriction Arteriolar smooth muscle relaxation due to direct contact with metabolites (such as K+, H+, CO2, adenosine) Time when heart is contracting, results in pressure generation and emptying Time when heart is relaxing, results in filling of the heart Heart activity composed of two stages: diastole and systole Amount of blood ejected by the ventricles per beat, difference between EDV and ESV, expressed in ml/bt Amount of blood in the ventricle just prior to contraction (i.e. following filling) Amount of blood in the ventricle just following contraction (i.e. prior to filling) Preload, afterload, and contractility Myocardial stretching (sarcomere length change) due to ventricular filling, associated with EDV Force which the myocardium must overcome to eject blood, associated with aortic pressure, aka MAP Forcefulness of myocardial contraction at any given preload, regulated by sympathetic activity Flow of blood back to the heart Increased contraction force (thus SV) in response to increases in EDV, related to length-tension relationship Lower atrial pressure due to negative inspiratory pleural pressure causing increased venous return Venous compression by surrounding skeletal muscle contraction that aids venous return States that VO2 is the product of blood flow and tissue O2 extraction States that VO...