KNES 348 Final Exam Study Guide PDF

Study guide KNES 348 Final Exam 1. List all of the components of the vascular system and their main role. heart- pumps blood into arteries; arteries- carries oxygen-rich blood AWAY from heart to body; arterioles- smaller branches of arteries that lead to capillaries; capillaries- sma...

Study guide KNES 348 Final Exam 1. List all of the components of the vascular system and their main role. heart- pumps blood into arteries; arteries- carries oxygen-rich blood AWAY from heart to body; arterioles- smaller branches of arteries that lead to capillaries; capillaries- smallest blood vessels and site of nutrient, gas, and waste exchange between blood and tissues; veins- carry deoxygenated blood back to heart and has valves to prevent backflow of blood; venules- collect deoxygenated blood from capillaries and return it to veins 2. Explain the differences between systole and diastole, and how these can influence changes in arterial blood pressure. systole- contraction phase, ejection phase (⅔ blood is ejected from ventricles per beat) causes RISE in arterial blood pressure; diastole- relaxation phase, filling with blood, no change in arterial pressure as heart is not actively pumping blood 3. Describe and graph the heart rate responses to submaximal exercise at 60% VO2max for 30 minutes (going from rest to exercise, and into recovery), and incremental exercise (0-100% VO2max). 4. Describe and graph the stroke volume response to a maximal exercise test (from 0-100% VO2max). 5. Contrast male vs. female stroke volume, cardiac output, and heart rate (similarities and differences). -stroke volume and cardiac output are different due to differences in body sizes and also size of heart and diaphragm; heart rate stays the same 6. Contrast trained and untrained stroke volume, cardiac output, and heart rate responses at rest and at maximal exercise. heart rate- lower in trained than untrained at rest. With exercise, heart rate increases. trained athletes are able to have a lower heart rate because they have a larger left ventricle which increases stroke volume, so heart rate does not need to be as high to reach the same cardiac output; stroke volume- higher in trained, increases with exercise due to trained people having underwent left ventricle hypertrophy; cardiac output- similar at rest, increases with exercise, higher in trained people than untrained after exercise. trained people are able to have a higher stroke volume than an untrained person. when trained person reaches their max heart rate, their stroke volume is higher which increases the cardiac output 7. Explain why HR responses to upper body exercise are higher than HR responses to leg exercise at the same workload. HR and blood pressure is higher because the amount of isometric contractions and increases sympathetic activity; higher heart rate in arm work is linked to a greater sympathetic outflow to the heart (arm); isometric exercises also increases heart rate above the expected value based on relative oxygen consumption; muscles being used will cause for dilation towards those muscles that cause for lower blood pressure due to lower peripheral resistance 8. Indicate the relationship between HR, stroke volume, and cardiac output. HR x SV= CO 9. Describe the factors that increase venous return during exercise. venous constriction- increases venous blood pressure and increases preload and cardiac output; muscle pump- force blood back to heart, one way valve prevents blood flow from going backwards; respiratory pump- changes in thoracic pressure pull blood= more venous return 10. List all factors that contribute to an increase in stroke volume and explain how each factor increases or decreases stroke volume. 1) left ventricle hypertrophy- pushes out more blood since it is larger and stronger 2) increase in the degree of stretch of cardiac muscles- pushes blood at a higher force 3) contractility- more blood is pushed out causing lower EDV 4) preload increase- the amount the ventricle can stretch and fill before contracting 5) afterload increase- amount of pressure exerted by arteries pushing blood out, affects ESV since it pushed a larger amount of blood out 11. Indicate which factors contribute to increased blood flow towards the exercising muscle during exercise and the relationship among these factors, for example: increased metabolic vasodilatation (autonomic regulation) increases the blood flow towards the muscles. redistribution- depends on metabolic rate (exercise intensity) autoregulation- blood flow increased to meet metabolic demands of tissue (vasodilation to muscles) vasoconstriction- of vessels of less active organs and tissues during exercise, as opposed to at rest (SNS) 12. During prolonged exercise (about 1-2 hours long) of submaximal exercise intensity, how do HR, stroke volume, and cardiac output change? HR increases to maintain cardiac output and make up for the decrease in stroke volume 13. List all of the factors that increase or decrease total peripheral resistance. viscosity radius of vessel -> vasoconstriction- decrease in diameter= increase total peripheral resistance; vasodilation- increase in diameter= decrease TPR and allows increased blood flow to active muscles; during exercise TPR decreases and prevents excessive increase in blood pressure 14. Explain why is so important to avoid dehydration during prolonged exercise. dehydration will cause and increase of viscosity which will decrease blood flow; can lead to cardiovascular drift- HR increases that occurs during prolonged exercise with little to no change in workload 15. Describe which changes in blood flow occurring in/to major organs and tissues in your body during exercise of high intensity. 1) at rest, approximately 15%-20% of total cardiac output is directed toward skeletal muscle 2) during exercise, 80-85% of total cardiac output is directed toward skeletal muscle in order to meet huge increase in muscle oxygen 3) during heavy exercise, the % of total CO that goes to the brain is reduced, blood flow reached the brain is slightly increased above resting values 4) blood flow in abdominal organs is decreased during exercise 5) vasoconstrict= organs (SNS)  6) vasodilation= skeletal muscles (autoregulation) 16. Explain the role of the cardiovascular control center in regulating cardiac output and blood flow during exercise. control center receives information from higher brain areas and receptors and directs whether we need to increase or decrease HR and stroke volume; medulla oblongata responsible for regulation of CO 17. List the receptors (and explain their roles) responsible for sending feedback information to the medulla oblongata during exercise. chemoreceptors- sense changes in pH or accumulation of hydrogen due to CO2 or hormones such as epinephrine and norepinephrine, O2 in arterial blood baroreceptors- sense changes in blood pressure and send impulses to medulla oblongata mechanoreceptors (muscle and joints)- sense activity and changes in muscles and joints 18. Describe the actions of the autonomic nervous system with increasing or decreasing cardiac output. PNS- fibers that supply the heart arise from neurons in the medulla oblongata that make contact with SA and AV nodes (acts as a braking system to slow down HR which lowers CO -> decreased HR= decreased CO) SNS- fibers reach the heart through the cardiac accelerator nerves which release norepinephrine which act on beta receptors of the heart which cause for myocardial contraction (increase stroke volume= increase in CO) 19. Explain the mechanics of pulmonary ventilation and how they lead to changes in pressure gradient favoring the movement of air into and out of the lungs. at rest, using pulmonary ventilation, which is the rhythmic movement of air in and out of lungs The lung and thoracic cavity expand to draw air in to decrease alveolar pressure. as air comes in there, there is more pressure then the lungs recoil to expel air airflow increases when there is more resistance in the pressure gradient OR decrease in airway resistance ventilation= tidal volume x frequency amount moved= minute ventilation 20. List the muscles involved in inhalation and exhalation at rest and during exercise. inspiration: REST= diaphragm; EXERCISE= external/internal intercostals, diaphragm, sternocleidomastoid, scalenes expiration: EXERCISE= internal intercostals, external obliques, internal obliques, transverse abdominis, and rectus abdominis 21. Explain the difference in the computation of minute ventilation vs. alveolar ventilation. 22. Graph and describe the ventilation responses to submaximal exercise 10-minutes long at 60 % VO2 max and a maximal exercise bout (0-100 % VO2 max). 23. Is the increase in ventilation during maximal exercise proportional to the workload? Why not? What is driving the exponential increase in ventilation at higher intensities? ventilation during maximal exercises increases PROPORTIONALLY until it reached ventilatory threshold, then increases EXPONENTIALLY because of the CO2 and lactic acid produced by the  muscles start to increase; to get rid of the waste, body needs to exhale by increasing its ventilation rate 24. Explain the role of the partial pressure of a gas (and how it is computed) in the regulation of gases’ movement into different tissues. PP is calculated by multiplying the barometric pressure and fractional concentration of the gas; gases follow their partial pressure gradient and move from area of HIGH PRESSURE TO LOW PRESSURE which allows for gas transport; this is important because it allows for oxygen to enter and CO2 to leave 25. How is most of the carbon dioxide transported in our blood? as carbonate ions (10% of CO2 is dissolved, 20% bound to hemoglobin, 70% transported as bicarbonate HCO3) 26. How is most of the oxygen transported in our blood? binding to hemoglobin 27. Explain the following statement: “Hb is 75% saturated.” the hemoglobin molecule has 75% of their oxygen binding sites are occupied by oxygen 28. Which factors increase the saturation of Hb with oxygen at the lungs, and which factors affect the saturation of Hb with oxygen in the tissues? increased saturation- PP of oxygen, affinity between hemoglobin and oxygen saturation with oxygen in tissues- PP of CO2, blood pH, and blood temperature Hb in lungs- low saturation of PO2 and low affinity of Hb drive Hb saturation up Hb in tissue- higher pH and lower temp increases Hb saturation 29. What does the a-vO2 difference stand for? arteriovenous oxygen difference -> the difference of O2 in arterial blood and venous blood= indicated how much O2 is removed from the blood in capillaries as the blood circulates in the body 30. If you have a higher a-vO2 difference, are you using more or less oxygen at the tissues? more oxygen at the tissues 31. How do we compute VO2 values? What is the formula? fick’s formula= maximal CO x (maximal a-VO2 difference) 32. What drives the conversion of carbonic acid into carbon dioxide and water in the lungs? partial pressure- the gas follows the gradient so the CO2 is moved out carbonic anhydrase- enzyme that breaks down carbonic acid into CO2 and water 33. Would the concentration of bicarbonate ions be higher in arterial or venous blood? arterial blood because it acts as a buffer to prevent changes in pH, breaks down carbonic acid 34. What does it mean to have a low pH? it is more acidic, higher concentration of hydrogen ions from lactic acid and carbonic acid 35. Which mechanisms allow us to sustain fairly controlled concentrations of H+ in our blood and tissues during exercise? ventilation as we exhale hydrogen and CO2 which is acidic 36. What are the main acids during exercise that contribute to the production of H+? lactic acid and carbonic acid 37. Are the concentrations of carbon dioxide, H+, and oxygen similar in importance regarding their contribution to the regulation of ventilation during exercise? CO2 and hydrogen are more important in regulating ventilation, the accumulation of these two are detected by chemoreceptors which tell the medulla oblongata to increase ventilation levels. Oxygen only affects ventilation rate when there is not enough oxygen in the air 38. What is the name of the receptors that monitor changes in body temperature? thermoreceptors 39. The respiratory control center is located where in our body? brain, medulla oblongata 40. What is the relationship between changes in pH and ventilation during incremental (maximal) exercise? As exercise intensity increases, so does ventilation. pH decreases as intensity increases 41. Describe the role of ventilation in sustaining acid-base balance during exercise. pH decreases during exercise due to the lactic acid and carbonic acid production, ventilation rate must increase to exhale all the acid 42. Explain the difference between an anatomical adaptation and a functional adaptation to exercise training. Provide an example for the cardiovascular system. anatomical- changes that happen to the body itself and are physical characteristics ex. left ventricle hypertrophy, number of mitochondria functional- changes how the body performs ex. blood volume, stroke volume, more ATP production 43. What does the principle of specificity indicate? Would you expect to gain larger muscle mass with endurance training or with resistance training? specificity indicates adaptation of muscle and other systems that are specific to the nature of exercise stress; gain larger muscle mass with RESISTANCE TRAINING 44. What key adaptations are responsible for a larger stroke volume in endurance trained people? left ventricle hypertrophy 45. Why can endurance-trained people attain larger minute ventilation values at maximal exercise? trained person has higher concentration of type 1 fibers and type 2 fibers that are MORE AEROBIC, as a result less lactic acid is produced so the person does not need to exhale as much to reach a higher workload 46. Which changes in the structure of skeletal muscle (anatomical adaptations) take place in response to endurance training? How do these changes contribute to increased arterio-venous oxygen difference? more capillaries- increase in the exchange of gases -> able to transport oxygen to the capillaries which would increase the a-VO2 difference increase in myoglobin- use more oxygen in the mitochondria and helps with the onset of exercise, more oxygen in mitochondria=increase the a-VO2 difference increase in mitochondria and its size- able to oxidize fats which will need to use more oxygen which also increases the a-VO2 difference increase in glycogen and triglycerides- able to produce more ATP through aerobic respiration, need to use oxygen for ATP production which will increase the a-VO2 difference  type 2a fibers look like type 1- have more mitochondria and capillaries hypertrophy of type 1- type 1 fibers are stronger which use aerobic respiration 47. What is the formula for maximal oxygen uptake? Why do endurance-trained people have higher VO2max values vs. untrained people? VO2 max= (cardiac output) x (a-VO2 difference) endurance trained people have higher VO2max values because they have a higher maximal cardiac output and a higher a-VO2 difference. higher cardiac output because of higher stroke volume due to left ventricle hypertrophy. higher stroke volume means they are able to reach the same HR as an untrained person but have higher cardiac output. they would have higher a-VO2 max due to the amount of capillaries and mitochondria, higher myoglobin, glycogen, and triglyceride and reach their ventilatory threshold later 48. After 8 weeks of endurance training would you expect to see lower lactic acid concentrations in the blood in response to the same submaximal exercise? Why? because the body is able to use more aerobic respiration during the same exercise, resulting in the body producing less lactic acid concentration 49. Graph the ventilatory responses to a maximal exercise bout for a trained and an untrained individual. Is the ventilatory threshold at the same intensity for both people? 50. Why do endurance-trained people have lower heart rate values during submaximal exercise and at rest in comparison to untrained people? the left ventricle has hypertrophies so is able to produce a higher stroke volume, resulting in the HR being lower to maintain the same cardiac output