final-142

Start Studying!

Terms

undefined, object

copy deck

why is it important to know the normal functions of the respiratory and cardiovascuolar systems?: to understand how humans respond to exercise, and to understand individual differences in physilogical response to exercise and anatomical and functional limits
What is cardiovascular drift: during prolonged exercise, stroke volume gradually decreases, and heart rate increases.
what regulates the exchange of oxygen and carbon dioxide in the alveoli?: partial pressures of the gases
where are the skeletal muscles which facilitate breathing?: in the thoracic cage Â– not in the lungs themselves.
how much greater may ventilation be during exercise than at rest?: 15 Â– 30%
Is exercise capacity limited by ventilation in a healthy person?: no.
How does the respiratory system aid in regulation of H+ concentration in the blood and CSF?: By changing the rate and depth of breathing.
what are the two contributors to the decrease in pH during exercise?: carbonic acid from production of CO2, and lactate from anaerobic glycolysis
what is a partial pressure?: the pressure of a given gas in a gas mixture, or in a liquid
what are the primary components of the respiratory system?: nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, lungs
how many bronchial branches are there and what are they called?: three: primary, secondary, tertiary
what leads to the alveoli of the lungs?: alveolar ducts
Why is smooth muscle important in the branching systems of the respiratory tract?: contraction and relaxation constricts or dilates the bronchioles, having a major effect on airway resistance.
What is the anatomic dead space?: VD: the volume of the conducting airways where gaseous exchange doesnÂ’t take place. (abt. 150ml in normal adults)
How many alveoli are in the human lungs?: Millions
which muscles are involved in active skeletal muscular activity during inspiration: diaphragm, external intercostals
how does expiration happen: passively
tidal volume: depth of breathing either inpired or expired.
inspiratory reserve volume: maximal amount (more) that can be expired after a normal inspiration
expiratory reserve volume: maximal volume of gas expired further after the resting after the end of a normal expiration.
residual volume: volume of gas remaining in the lungs at the end of a maximal expiration
Total lung capacity is the sum of what: TLC: residual volume plus vital capacity
Define total lung capacity: the total amount of gas contained in the lung at the end of a maximal inspiration.
Forced vital capacity: FVC: maximal volume of gas that can be expelled by voluntary effort following a maximal inspiration.
inspiratory reserve: IRC: is the maximal volume that can be inspired from the resting expiratory position.
functional residual capacity: FRC: volume of gas remaining in the lungs at the resting expiratory level. expiratory reserve volume plus residual volume
What are the dynamic lung volumes?: ventilatory manoevers designed to distinguish between healthy and diseased lungs
What are three main dynamic lung volumes?: FEV, FVC, and MVV: forced expiratory volume, forced vital capacity, maximum voluntary volume
define FEV: Forced expiratory volume Â– maximum volume of air that can be expired in one second
What are the differences between lung volumes when lying downor standing?: decrease when lying down, increase when standing.
why?: abdominal contents push on diaphragm, decreasing inspiratory capacity because the diaphragm canÂ’t descend as far, and intra-pulmonary blood volume increases when lying down, meaning that there is less space available for air.
Does lung function limit exercise performance at sea level?: No, as level of ventilation at maximum aerobic exercise is still usually 25% less than the maximum voluntary ventilation possible.
Can training help with lung function?: To a degree, but there is little difference between trained and untrained healthy individuals lung function. Where it makes a difference is for those with respiratory disorders.
What is VA: Alveolar ventilation. The volume of air that reaches the alveoli per minute.
Why is alveolar ventilation important?: because this is the only air that reaches the lungs and thus participates in gas exchange with the blood.
What is minute ventilation?: VE volume of air breathed each minute, determined by measuring the tidal volume of each breath times the number of breaths per minute.
What is FR: Respiratory frequency
what is the equation for minute ventilation: VE=(VT) (FR)
Alveolar ventilation equals what?: difference between alveolar ventilation and deadspace ventilation.
Does all of the air that is moved through the mouth and nose participate in gas exchange at the alveoli?: No.
What are ALL lung volume values corrected to?: BTPS Body temperature and pressure saturated
What does BTPS match?: matches the conditions that exist inside the lung
What are the air volumes usually measured at?: Normal atmospheric temperature and pressure (because weÂ’re measuring with machines in the atmosphere, not inside the lungsÂ…) This is called ATPS.
What does ATPS stand for?: Atmospheric Temperature and Pressure Saturated.
What are two categories of pulmonary disorders?: restrictive disorders and obstructive disorders
obstructive disorders cause what: blockage or narrowing of the airways causing increased resistance
What are examples of obstructive disorders?: asthma, bronchitis, emphysema. Bronchiolar obstruction can be caused by inflammation, edema, muscle constriction, or secretions.
What is the result of obstructive disorders?: difficulty moving air rapidly in and out of lungs, so reduction in functional capacities. results in FEV/FVC of less than 80% of normal. Also, airways collapse on expiration with these disorders, so air is trapped, which leads to an increase in residual volume, functional capacity, and total capacity.
What occurs in restrictive disorders?: Damage to lung tissue itself, limiting lung expansion.
what are two examples of restrictive disorders: pulmonary fibrosis and pneumonia. These make lung tissue more fibrous and stiff, so difficult to expand. All lung volumes are reduced.
what factors must be taken into account when interpreting pulmonary function test results?: medical and occupational history, smoking habits, chest S-ray.
describe three factors that effect vital capacity: pulmonary tissue recoil, bronchiolar dimension and health, health and number of alveoli
what are the two sites of gaseous exchange in the body?: alveoli, capillaries
distinguish between obstructive lung disease and restrictive lung disease: obstructive disorders restrict the passageways that bring air to the lungs, whereas restrictive disorders affect the lung tissue itself, usually limiting its elasticity and ability to expand to take in air.
For each pulmonary function variable, indicate how it is effected in people with emphysema or chronic bronchitis: patients with OBSTRUCTIVE (bronchitis) disorders have normal or greater than normal total capacity, but drastically reduced flow. Patients with RESTRICTIVE (emphysema) disorders have reduced volumes, (total capacity, residual capacity, vital capacity).
discuss the role of the cost of ventilation with respect to limiting athletic performance: As ventilation at maximal exercise is usually only 80% of maximum possible ventilation, there is no cost of ventilation with regard to limiting athletic performance.
describe the intrapulmonary and intrapleural pressure changes and the movement of the air into and out of the lungs at rest: Passive diffusion due to pressure differentials witin alveolar sacs and pulmonary capillaries. At rest: atmos: 760mmHg,lung:760mmHg, Intrapleural:755mmhg=No air in or out. Inspiration: atmos: 760mmHg, lung:759mmHg, Intrapleural: 752mmhg =7mmHg pressure difference across lung wall, lung expands, air is sucked into lung. Expiration: atmos: 760mmHg, lung:761mmHg, Intrapleural: 758mmhg =3mmHg pressure difference across lung wall, lung contracts, air is forced out of lung.
what is dyspnea?: laboured breathing
Describe the nature of ventilatory changes before, during, and after exercise (during recovery).: Ventilation increases during exercise. The increase is proportional to increases in VO2 and VCO2 by the muscles. However, minute ventilation VE is more a function of CO2 removal than VO2, as we know that ventilation increases much more than VO2.
What are molecules that contribute H+ called?: acids
What are molecules that combine with H+ called?: bases. Neutralize.
Describe the relationship between partial pressure and concentration of gases in a gas mixture: partial pressure of a given gas is equal to its concentration within an overall gas mixture. Partial pressures of all gases in the mixture equal 100% of the total pressure of that gas.
discuss the partial pressure of a gas in a liquid: partial pressure of gas within a liquid is a function of the pressure of the gas above the liquid, plus the solubility of the gas in the liquid. Gases always move down a pressure gradient from high to low concentration, and will equalize their concentration, whether in liquid or solid form. There is a constant exchange of molecules therefore, between gas and liquid, to ensure a uniform gaseous concentration.
describe the partial pressures of oxygen and carbon dioxide in the alveloi versus the pulmonary capillary blood: Partial pressure of oxygen is highest in the alveoli, and lowest in the tissues, whereas the partial pressure of carbon dioxide is highest in the tissues and lowest in the lungs. Alveolar PO2 is 100mmHg, PO2 arterioles 100mmHg, Venous blood=40mmHg. Lung PCO2 = 40mmHg, Venous Blood PCO2=46mm Hg.
describe four factors that affect gas exchange in the lung: thickness of respiratory membrane, (affects length of diffusion path), number of RBCÂ’s or their hemoglobin concentration or both, surface area of the membrane available for diffusion, whether restrictuve lung diseases are present which inhibit oxygen availability.
define Â“diffusion capacityÂ”: volume of oxygen that passes the alveolar capillary membrane per minute per mmHg pressure difference beween alveolar air and pulmonary capillary blood.
how and why does diffusion capacity change during exercise?: 3x more. increased lung volumes during exercise as additional muscles working open up lungs more, more forceful breathing brings more air in (incr. Â“ventilationÂ”), surface area in lungs ins increased due to opening up of more capillaries in lungs, greater volume of blood flowing through lungs.
describe how oxygen is transported in the blood: attaches to Â“hemeÂ” particles of hemoglobin present in red blood cells. 98% of it travels this way, while the other 2% travels in solution in the plasma itself.
what is meant by the oxygen carrying capacity of hemoglobin, and the percent saturation of hemoglobin: percent saturation of hemoglobin (SO2). 02 carrying capacity relates to how much oxygen may actually be transported by the blood, which is a function of the number of red blood cells, and the hemoglobin concentration of those cells, or both. Percent saturation of the hemoglobin refers to how much of the hemoglobin that is actually available is carrying oxygen. Max saturation is 4 o2 molecules per hemoglobin, as each hemoglobin has 4 hemes, each capable of carrying one o2 molecule.
what is the maximum possible oxygen saturation of blood?: 20.1 ml 02/100 ml blood.
what is the normal pH of human blood?: 7.4
what happens to the pH of blood during exercise?: becomes acidic (as low as 6.8)
what are the two largest contributors to the increased acidity of blood during exercise?: CO2 produced through aerobic metabolism, (carbonic acid H2CO3), and lactic aid from anaerobic glycolysis.
How does the body work to make blood less acidic?: Removes H+ molecules. arterial and spinal chemoreceptors sense the additional H+, autonomic nervous system reacts Â– facilitates removal of CO2 by increasing breathing rate, which Â“blows offÂ” CO2, which reduces H+ concentration, making blood less acidic.
explain the significance of oxyhemoglobin dissociation curve with respect to gas exchange and transport: gases always diffuse passively down the oxyhemoglobin curve, which facilitates transfer of gases. this is because tissues have used their oxygen, making the o2 concentration there lower. The percent o2 in the capillaries is higher as theyÂ’ve recÂ’d o2 from the lungs. o2 dissociates from the hemoglobin and is therefore transferred to the tissues as a result of the gradient. Neediest tissues get the 02 first. temperature and acidity affect the curve Â– o2 dissociates faster with higher acidity and temp (i.e. during exercise).
during exercise there are changes in blood acidity, temperature and CO2. How do these factors affect the oxyhemoglobin dissociation curve and what is the significance of these effects?: acidity and temp reduces the effectiveness of o2 binding to hemoglobin, so causes dissociation. inc. temp + acidity facilitates o2--> tissue transfer. Curve moves down and to the right. Acid+temp reducing o2 binding: Bohr effect.
describe the conduction system of the heart: inherent contractile rhythm. depolarizing impules that originates in SA node, generating wave of depolarization that activates the heart muscle, due to structure of heart cells that makes them Â‘leakyÂ’ to sodium ions, thus tranferring the electrical signals.
how does the heart muscle receive its blood supply?: coronary circulation system-left main coronary artery- two branches- circumflex to left lateral and posterior wall, and anterior descending branch Â– and right coronary artery to right ventricle and posterior heart.
What is an ECG and how is it recorded?: electocardiogram, recorded using electrodes placed on the body which record changes in electrical activity across the myocardium, graphically displayed as a function of time. used to clinically detect abnormalities in heart rhythm or contractile properties.
describe the major changes in the distribution of blood flow that occur during exercise.: Blood flow to the skeletal muscles changes from approximately 15 Â– 20% of system blood flow to using about 85% of the blood flow during maximal exercise - because of: increased blood pressure, changes in the diameter of certain arterioles in the body, as follows. arterioles surrounding visceral organs (especially in the abdomen, i.e. liver, stomach, kidneys, etc.) constrict, so less blood flow to the visceral organs, thus allowing more of the blood to go to the arterioles of the muscles. To allow the increased bloodflow, the skeletal muscle arterioles dilate. These changes are regulated by the sympathetic nervous system, which also controls the increased heart rate and stroke volume that occurs during exercise.
functional syncytium: important to ensure that heart works effectively as a pump. anatomical interconnection of all of the cells of the myocardium, making it function as a single unit with coordinated contractions.
Pwave: atrial depolarization at beginning of atrial contraction.
QRS complex: ventricular depolarization at beginning of ventricular contraction.
Twave: later, more rapid ventricular repolarization.
cardiac arrhythmia: indicate conduction problems in atria, ventricles, nodal tissue, bundle of his or purkinje fibres. abnormal cardiac rhythm Â– too fast (tachycardia), too slow (bradycardia) or variable.
muscle pump: mechanical action of rhythmical muscle contractions that aids venous return by compressing veins, squeezing blood back through venous system and valves, back to heart.
respiratory pump: veins of thorax and abdomen are emptied during respiration and refilled during expiration. happens both because of respiratory muscles squeezing on veins near thorax, and as a result of the same pressure gradients which facilitate breathing.
plasma: non cellular part of blood which communicates continuously with interstitial fluid through pores of capillary membranes. makes up 50-60% of the blood by volume.
erythrocyte: red blood cell. small biconcave disc. canÂ’t replicate. 7Mm in diametre, 120 day lifespan. 5-6 million in the body. have an important role in transporting o2 and co2 in body in the hemoglobin of their cell walls.
hemoglobin: o2 and co2 carrying molecules within erythrocytes. each hemoglobin can carry 4 o2 in hemes, and co2 in globin.
oxygen hemoglobin dissociation curve: graph which shows the relationship between the partial oxygen pressure of blood and how much of that blood dissociates from its hemoglobin, tranferring the o2 to the tissues under various conditions Â– rest, exercise.
bohr effect: increase in temp and acidity which decreases effectiveness of binding of o2 --> hemoglobin. o2 dissociation curve moves down and to right with bohr effect.
systole: contractile phase of cardiac cycle Â– top number in blood pressure. 1/3 of total cardiac cycle.
diastole: relaxation phase of cardiac cycle Â– no electrical or mechanical activity. 2/3 of time. bottom number in bp.
cardiac output: amt of blood pumped by either left or right ventricle per minute. L and R must have same output to maintain equality within pulmonary and systemic circuits. output equals heart rate times stroke volume, or:Q=HRxSV.
stroke volume: amount of blood pumped by either left or right ventricle per minute
describe the changes in heart rate and stroke volume that occur during exercise: heart rate increases linearly with increased workload until max. heart rate is reached. stroke volume increases to its highest values during 40% submaximum effort, and remains constant through to maximal effort.
how does stroke volume increase during exercise: during prolonged exercise, stroke volume eventually reduces slightly, while heart rate increases. (after 1 hr.plus of exercise.)
how is the redistribution of blood flow related to the arterio-venous oxygen difference?: reduced o2 at muscles works in concert with other chemical changes to result in vasodilatin (through release of vasodilators) which redistributes blood to active skeletal
describe how and why systolic and diastolic blood pressure change during exercise: systolic increases due to the increase in cardiac output (stroke volume and heart rate) and increase4d resistance in the less active tissues. diastolic doesnÂ’t change very much because of decreased periphera resistance due to arteriole dilation at skeletal muscles.
what is resistance to blood flow, and how is it related to hypertension?: resistance to flow is additional friction between blood and the walls of the blood vessels caused by the viscosity of blood, length of the blood vessels, diametre of blood vessels Â– smaler diametre means that more blood is in contact with the walls Â– hypertension constricts vessels, therefore increases resistance.
what is the equation for vessel diametre to blood flow resistance?: resistance is inversly proportional to the diameter to the fourth power. (So ¼ less diametre would be equal to sixteen times more resistance.)
describe three mechanisms that play a role in aiding the return of venous blood from the legs to the heart.: muscle pump, respiratory pump, valves of venous system (pressure of arterial flow tooÂ…)
why does the average male have a higher maximum oxygen uptake than the average female: larger with more muscle fibres, more o2 reqÂ’d.
ergometer: adjustable piece of laboratory equipment which can present different work rates to an exercising subject. (can be bicycle, rowing,treadmill etc.)
VO2 max: maximum amount of oxygen that can be used by an individual per minute.
MET: metabolic equivalent.amount of oxygen required per minute under quiet resting conditions = 3.5ml/kgm body mass/min
Discuss the factors effecting maximum aerobic power: mode of exercise (because local capillarization and enzyme production are muscle and sport Â–i.e. training specific), heredity, age, gender.
whatÂ’s the difference between heat conduction in air versus water?: 25% greater in water
what are the advantages and disadvantages of using a bicycle ergometer compared to a treadmill for exercise testing?: adv:cheap, portable, non-electrical, subject is stable on it. disadv-canÂ’t obtain as high a VO2 max, cycling also not as common an exercise as walking/treadmill.
discuss the assumptions used in the prediction of maximum aerobic power from submaximum exercise.: assumes that there is a relationship between heartrate, o2 uptake and workload, assumes that maximal heartrate for a given agegroup is predictable and fairly constant, assumes that the biomechanical efficiency of the activity is the same for all groupsÂ… (varies greatly between individuals, body types, and trainingÂ…)
what is a soma?: cell body of a neuron, which resembles other cell types, contains the nucleus, cytoplasm, and other organelles (mitochondria, golgi apparatus, endoplasmic reticulum etc). It also contains chromatophylic substances called nissl bodies. The soma is responsible for metabolic role.
what is a spatial summation?: additive effect of many small stimuli from different pre-synaptic terminals that add together to form a nerve summation.
what is a temporal summation?: summation that occurs because of multiple discharges from the same pre-synaptic terminal.
what is GTO?: golgi tendon organ. proprioception sensor located in the tendon fibres at the musculo-tendinous junction. senses stretch, and when activated during a strong stretch cause the contracted muscle to relax when there is potential for injury.
what is an alphamotoneuron?: larger motor nerves which innervate regular Â“extrafusalÂ” muscle fibres (i.e. non-muscle spindle muscle fibres)
what is a gamma motoneuron?: thin motor nerves which innervate the special stretch receptor Â“intrafusalÂ” muscle fibres.
explain how information is relayed through the nervous system: nerve Â–>nerve, nerve Â–>muscle, via chemical transmitter substances released at ends of the nerve in response to stimuli. Happens because of selective ion permeability of nerve membrane.
what three functions do muscle spindles play in the activation of skeletal muscle?: relay information to the CNS about length of muscle being tonically stretched. respond to velocity of change in length (orphasic stretch), co-activate alpha and gamma motoneurons dynamically to keep muscle at its peak operating length during operation.
nerve impulse: because of selective permeability of nerve membrane to+ and Â– ions, potential (voltage) exists between inside and outside (across membrane), high concentration of positive sodium ions OUTSIDE nerve membrane makes outside positive, inside negative. When action potential generated by stimuli, sodium ions rush into nerve via chemically gated channels, which causes a depolarization of the neuron, sending a signal called an action potential all the way along the length of the nerve fibre.
desribe the monosynaptic (knee jerk) reflex: tapping the patellar tendon stretches the quadriceps and muscle spindle in the quadriceps, sensory impulses are sent to the spinal cord (CNS) via afferent neuron. signal passes to the motor neuron, which sends an impulse to the muscle, causing the muscle to contract, and extending the lower leg in the Â‘knee jerkÂ’ reflex.
distinguish between ability and skill in the performance of a specific task: ability is a general enduring trait that is effected both by learning and genetics, i.e. balance. skill is specific to a given task, and is gained through experience Â– i.e. performing balance beam in gymnastics using balancing ability.
how would you distinguish between a skilled and an unskilled athlete?: skilled performer is able to anticipate variations and reduce the time that it takes to make a choice of responses once a given signal is sensed.
distinguish between gross motor skills and fine motor skills and use examples of specific motor tasks in your answer.: gross motor skills involve large musculature as the primary basis of movement. precision is usually not important Â– walking, running, jumping. Fine motor skills use smaller muscles to achieve successful execution of tasks which usually require a higher degree of precision and involve hand-eye coordination: drawing, writing, etc.
what are the three stages of skill acquisition?: cognitive, associative, and autonomous. These tend to happen as a continuum in learning skills.
explain the three stages of skill acquisition. give an example of how an athlete would progress through these stages.: COGNITIVE-understands *which* movements need to be done, NOT HOW. Errors frequently made, usually large. ASSOCIATIVE-can reproduce reasonable approximation and refine movements.errors smaller. concerned with HOW to do movements Â– uses proprioceptive rather than visual info. more is becoming automatic. AUTONOMOUS- performs movements automatically, while able to think about other things.
list three functions that knowledge of the results provides in learning: guide error correction, reinforce correct performance, motivate individual.
describe how different types of knowledge of results would be useful to an unskilled player, and a skilled player.: concurrent Â– during activity Â– not good for novices. better for experts who can think while doing, and donÂ’t have to concentrate on each part of the activity. terminal (after activity) Â– better for novices Â– less sensory overload during the activity.
Explain how and when videotape feedback could be useful to an athlete.: for beginners, need instructors to point out information, and use for at least five weeks. give them a chance to see visually Â– different learning method than proprioception.
What is an EPSP: Excitatory Post Synaptic Potential.
give examples of the three different forms of transfer of learning: Positive transfer Â– one skill easily transfers to another because skills required are very similar in the two tasks Â– rollerblading and iceskating. Negative transfer Â– when knowing one skill interferes with ability to learn new skill (usually a temporary state) Â– badminton player trying to learn tennis. bilateral transfer Â– transfer learning of a skill from one side of the body to the other Â– learning scales with one hand on a piano, then learning them on the other.
explain how bilateral transfer could assist a piano player.: learning scales with one hand will facilitate ease of learning on other hand. Only with motor skills. Learning motor skills is not associated with a specific limb, so learning on one side will help other side.
how does intrinsic motivation affect the rate of learning of a skill?: performance is a result of skill times motivation, so motivation is required to learn new skills, and can speed the rate of learning of new skills.
what factors affect motivation?: individual knows theyÂ’re being evaluated, outcome is success or failure, individual alone is responsible for the outcome, is there risk or uncertainty? immediate knowledge of outcome.
what factors in motor learning influence a childs decision to participate in a sport?: large psychological component as well as skills and abilities, and perception of skills and abilities, motivation, Â‘role modelÂ’
discuss how you would use goal setting as a motivational tool to improve performance: set goals with clear objectives, meaningful to performer, obtainable goals, short and longterm goals, personal to performer.
distinguish between motor learning and motor development: motor learning is a permanent change in performance levels due to practice while motor development occurs because of growth and maturation of nervous system and motor system.
define motor learning: practicing motor skills until a permanent change comes about within the motor cortex to cause the skill to be Â‘rememberedÂ’ as an Â‘engramÂ’
what is an engram?: permanent trace left in neural tissue by repeated stimulation during practice
define kinesthesis: sense of the position of the body in space, and its different parts relative to one another.
knowledge of results: knowing the results (either inherently or by specifically receiving feedback) is key to motor learning Â–without knowledge of how weÂ’re doing Â– we canÂ’t learn.
transfer of learning: when the learning of one skill has transferable applications in other skills.
what is the scientific method?: use of experimentation to disprove a theory
distinguish between basic and applied research.: basic research seeks to find answers to questions and disprove theories whereas applied research is a way of taking what is known, and using facts to design elements of the real world based on knowledge.
state boyles law and explain why it is important at altitude or underneath the surface of the water: at a constant temperature, the given mass of a gas is inversely proportional to its volume. Gas volume in the body decreases with descent to depths during diving, whereas at altitude, expansion of gas due to altitude means that the gas is less dense, meaning that there is less oxygen available for physiological processes.
using the principle of charles law, explain how body temperature influences ventilatory volumeNOT SURE IF THIS ANSWER IS CORRECT!!: at a constant pressure, volume of gas is proportional to temperature, so if temperature increases, gas volume increases. At sea level, a temperature increase would mean that in order to achieve the same level of alveolar ventilation as an earlier temperature, larger volumes of gas would have to be consumed to achieve the same 02 level ??? Ventilatory volumes are usually measured at ambient temperature, so will need to be converted to body temperature.
why does it seem that exercise is more tiring at altitude than at sea level?: lowered partial pressure of oxygen in the air due to reduced air density at altitude. This makes physical work more difficult because less air is available for energy.
how is the physical environment changed at altitude?: Reduced atmospheric pressure and lower partial pressure of oxygen means that less oxygen is available in a given volume. Also colder, and more radiation exposure.
describe the immediate and longterm adjustments that occur following exposure to reduced oxygen pressure (hypoxia). What mechanisms allow the peripheral tissues to extract more oxygen following acclimation to altitude?: immediate: HYPERVENTILATION Â– stabilizes after about a week. Increases alveolar 02, blows off CO2, decreasing H+ concentration in blood. CARDIAC OUTPUT Â– UP- stroke volume stays the same, but heart rate rises Â– PULMONARY VASCULAR RESISTANCE RISES = higher blood pressure in pulmonary circulation (can lead to pulmonary edema) Â– after a few weeks: INCREASED RBCÂ’S Â– and hemoglobin concentration Â– increased o2 in arterial blood Â– ELIMINATION OF HCO3- in urine (bicarbonate) causes decrease in pH of blood Â– makes it easier for body to use what little o2 there is Â– TISSUE CHANGES Â– increased muscle and tissue capillarization and increased mitochondral density and myoglobin concentration, plus enzyme enhancements to increase oxidative capacity. CHANGES REVERT AFTER 2-3 WEEKS AT SEA LEVEL.
why is maximal exercise performance reduced at altitude? how would you expect an individuals performances in sprint events, endurance events, and throwing events to change at altitude?: hypoxia limits O2 availability = lover VO2 max, less o2 to heart. In shorter duration activities, effect is less because activities donÂ’t depend as much on aerobic metabolism. throwing and jumping events favored (?) at altitude as force of gravity is less. (sounds like bs to meÂ…)
how does a person adapt to altitude over a period of time?: The longer at altitude, the better that persons aerobic performance becomes at altitude, though it is seldom as good as it is at sea level standards. Performance increases due to the physiological changes that allow more O2 to be extracted and used.
how does training at altitude benefit performance at altitude and on returning to sea level?: For work that is to be done at altitude, training at altitude can produce rapid and greater changes than training at sea level when the event is to be performed at altitude, however these changes are not very much greater, and they quickly disappear upon return to lower altitudes.
describe the measures that can be used to reduce the onset and severity of altitude sickness.: Climbing slowly, increasing carbohydrates in the diet, Â“work high, sleep low,Â” however if altitude sickness does come on Â– administer o2, and move to lower level, avoid pulmonary edema! consult physician!!
describe in detail how the body loses heat: radiation, conduction, and evaporation. Body gives off electromagnetic waves which dissipate heat, conducts heat through other surfaces that it is in contact with if they are colder (applies to water, especially), and through sweating or respiratory evaporation, it loses heat, and the evaporation causes a cooling at the surface where the moisture is lost from.
how does the thermoregulatory system maintain a relatively constant temperature?: Hypothalamus senses changes in the temperature via three major thermoreceptor areas: skin, anterior hypothalamus, and deep body receptors (spinal cord, viscera, veins), and compares it to a set point (body temp 37C). If this varies, it sends signals automatically to effectors (muscles Â– shivering, sweat glands Â– sweating) that work to correct the temperature fluctuation. when fixed, the hypothalamus senses this and Â‘turns offÂ’ the effectors.
what is wind chill and why is it important to understand it?: Convective cooling power of the wind, which increases the cooling effects of wind with increased velocity. It provides a means for us to quantify heat loss from a body. Flesh can freeze due to windchill, it can happen very quickly, and can lead to far more serious problems (frostbite, hypothermia, death.)
Purpose of functional residual air?: acts as a buffer so that incoming breaths have only small effect on alveolar air composition Â– stability.
discuss the factors that may effect the human response to cold: Skinfold thickness Â– more subcutaneous fat= more insulation Â– better able to deal with cold. Gender Â– women lose heat more rapidly. Though they have more fat, they generally have more surface area through which to lose heat (also why they float better) age Â– children and aged arenÂ’t as adequately equipped to deal with heat loss, as effectors, hypothalamus, and neural connections are not yet developed in kids, and may be damaged by aging in elderly. clothing Â– layers best in cold Â– need an air layer by skin, and air trapped between thicker insulation layers for warmth, stay dry.
What other factors come into play at altitude other than strictly hypoxia and altitude sickness?: solar radiation: snow blindness, sunburn - dehydration, increased risk of hypothermia, higher level of perceived exertion (mental factors)
describe the advice that you would give to someone to avoid hypothermia: stay dry, insulated, eat carbs, remain hydrated, wear a hat, stay active, stay out of the wind and wet
explain the effect of cold exposure on the energy cost of work: Glycogen is used at a faster rate during anaerobic metabolism, so fatigue occurs earlier. During cold exposure, o2 dissociation curve moves to the left, meaning that it doesnÂ’t dissociate as readily from hemoglobin, so there is less o2 available for the tissues. Tissues become more anaerobic, which burns off energy more quickly, causes metabolic acidosis, and cn reduce both brain function and cardiac output. Bad positive feedback loop.
What is the weight of one atmosphere?: 760mmHg, or 14.7 psi at sea level.
At 10 metres below the surface of the water, the weight of water above the diver is equal to one atmosphere. Why is this true?: At sea level, the weight of one atmosphere of air is 14.7 psi. Salt water weighs 64 pounds per cubic foot, which can also be converted to psi. When converted, we find that at 10m, the psi of water is equal to 14.7 psi, or one atmosphere. Water is not compressible, so that means that its density remains the same, meaning that the total pressure on a diver increases proportionately with increased depth.
Discuss the effects of increasing and decreasing pressure while holding temperature constant on a given volume of water and a given volume of gas: gas compresses with increasing pressure, meaning that it will become more dense, and will expand, becoming less dense with decreased pressure. Water is not compressible, so increasing and decreasing the pressure will not effect the volume
describe how a diver may suffer air embolism: En embolus is any object which enters and becomes lodged in a body vessel. Air embolism occurs when a diver breaths from a SCUBA tank while at depth underwater (doesnÂ’t have to be a great depth Â– anything beyond 5 feet) then holds their breath while ascending. The gas within the lungs expands during ascent, causing rupture of the alveoli. Embolism occurs because the expanding gas in the lungs then enters the ruptured arteries of the lungs, and travels through the vessels where it Â‘plugsÂ’ vessels (especially to the heart and brain.) This can cause death.
what is spontaneous pneumothorax, and how is it treated?: Spontaneous pneumothorax is spontaneous lung collapse. Following lung rupture, air moves from the ruptured lung into the pleural cavity, where it continues to expand upon ascent. This increasing pressure in the pleural cavity forces the lng to collapse, and it may be severe enough to push the heart and lungs to the opposite side of the thoracic cage.Surgery is required to remove the air bubble via a needle and syringe. Death may result from pneumothorax.
what is the effect of nitrogen narcosis on a diver??: Nitrogen narcosis effects divers in a way similar to alcohol, impairing judgement, slowing mental capacity, fixating ideas. It effects the CNS.
how may one avoid developing the bends during a dive?: bends occur because gases (nitrogen) is absorbed (forced, by pressure actually) into the tissue and body fluids when placed under pressure during diving. If this pressure is released too quickly upon ascent from the depths, the gases release quickly, bubbling out of the tissues, which is what we call the bends. The only way to avoid the bends is by carefully controlling ascent from the depths, (by carefully following the prescribed wait and ascent patterns for given depths.)
what are the physiological principles underlying oxygen poisoning while diving?: Using 100% oxygen while at depths, in a closed circuit diving system causes more oxygen to be forced into solution, due to the increased pressure, coupled with the increased oxygen concentration. When there is plentiful o2 available in solution, the tissues use this first, which leaves 02 in the Hg, also with no room to remove CO2. o2 and co2 then build up in the tissues. If it exceeds 1520mmHg for more than half an hour to an hour, it can disturbs cerebral blood flow, causing irritation, muscle twitching, nausea, confusion, and can lead to pneumonia.
what is the importance of the eustachian tube for someone who descends below the surface of the sea or ascends to altitude?: connects the middle ear to the back of the throat, and is the main structure that equilibriates the middle ear with the outside environment, by transferring air from lungs. If blocked, pressure can build up, so that on descent, it can even rupture eardrum. Occurs both when diving, and if descending from altitude in an aircraft (usually fine when hiking/mountaineering as descent is slower).
how does an individual prevent squeeze while diving?: squeeze occurs during descent and is the result of pressure differentials between the inside of the mask, and the water outside. To avoid squeeze, a mask is worn over the eyes and nose, and air is blown out through the nose to equalize the mask pressure. Otherwise, a vacuum forms which can rupture vessels around the eyes.
what limits the size of a snorkel?: Pressure effects, and the effect of Â‘dead spaceÂ’ within the lungs limit snorkel size. The volume within a snorkel effectively becomes additional Â‘dead spaceÂ’ of the lungs, meaning that in order to achieve the same alveolar ventilation, the tidal volume must increase by the volume of the snorkel.
why is it dangerous to hyperventilate prior to breathhold diving? what is paradoxical drowning and how may it be avoided?: hyperventilating prior to breathhold diving overrides the bodyÂ’s natural instinct to breathe, by fooling the body into thinking that more o2 is available (because CO2 is blown off during hyperventilation). This means that if the diver waits too long to come up for air, there wonÂ’t be enough available. This is coupled with the fact that upon ascent, the partial oxygen pressure drops even further because of gas expansion, which can cause the diver to lose consciousness and drown. This is called Â‘paradoxical drowningÂ’ because it can happen to very skilled swimmers and athletes also. It can be avoided by NOT HYPERVENTILATING in or around water!
define ergonomics: study of application of biology and engineering to workers and their environments Â– user centred approach to design.
what training does an ergonomist need?: anatomy, anthropometry, biomechanics, design, engineering
briefly explain how the study of kinesiology relates to the field of ergonomics.: kinesiology is the study of human movement, structure, function, and relation to human performance. Ergonomics can be seen as a practical application of kinesiological studies, combined with design, to create structures that humans are meant to interact with in the environment.
you have been asked to design a new chair for a classroom at SFU. What information do you need to complete this task? what features of the chair design do you have to address for a standard lecture chair?: Length of time people will be sitting in it, design of room, task, if writing desk to be incorporated, if to sit under table, if part of a workstation, what size range of people, sitting height, stature, buttock to knee length, how chairs are to be arranged, yadda yadda.
Draw the largest of the kitchen appliances in your home or apartment. Analyze the work triangle. How would you relocate the fridge, stove and sink to improve kitchen efficiency?
from the ergonomists point of view, list the major factors which need to be incorporated in the design of a pair of scissors (age, gender, handedness): direction that the force is going to be applied, shape of hands, including age, grip (left or right) surface quality, gender Â– womens hands smaller Â– smooth running Â– eliminate strain, design so that hand and wrist are in natural position.
back injuries lead to a significant amount of lost work time. briefly explain the factors which need to be considered to reduce the number of back injuries at a job site where heavy boxes have to be unloaded from trucks and stored in a warehouse.: worker characteristics Â– training, age, physical health, strength, material characteristics Â– what is being lifted, task characteristics Â– frequency of task, workplace arrangement, pace, temperature, vibration, work practicesÂ… may recommend training program, redesign work practices or tasks
Describe how to measure lung volumes and capacities: Collens 9L respirometer Â– slow speed first Â– 32mm/minquiet breathing first Â– check equipment 2. at end of normal expiration, forcefully expire all air Â– ERV, 3. quiet rest, record temperature, 4. end of normal respiration, have subject inhale forcefully as much as possible IC, 5. quiet breathing, forceful maximal inhalation and forcrul maximal exhalation = VC 6. decrease flow, remove soda lime canister, turn machine to Â‘highÂ’ speed, breath out as fast and as far as possible Â– timed forced expiratory volume. 7. subject rest, machine to slow again. reconnect. breath as fast and as deeply as possible. (maximum breathing capacity) 9. read barometric pressure 10. do calculations
Why is it important to have the bell filled with oxygen rather than room air when measuring a subjects minute ventilation on the Collens 9litre respirometer?: This is a closed circuit system, so the subject will use up all of the oxygen during these breathing exercises. Oxygen must be replenished, or they could pass out.
Explain the difference between gas volumes at ATPS, STPD, and BTPS: ATPS= ambient and temperature pressure, saturated Â– this is how the machine measures the volumes at ambient air temperature and pressure, with moisture in the air (saturated), BTPS Â– body pressure and temperature, saturated Â– what we correct to via a conversion by figuring out the amount of moisture in the air at a given ambient barometric and temperature, STPD Â– standard temperature and pressure, dry Â– this is a standard that can be used for comparing results as it is a more Â‘absoluteÂ’ value Â– uses 0celcius (273 Kelvin) at 760mmHg.
Describe various factors that effect vital capacity: age, sex, overall health, height (length of lungs)
when measuring blood pressure you must listen for the korotkoff sounds at the brachial artery using a stethoscope. Why canÂ’t you hear these sounds before the cuff is inflated?: The sounds are the result of turbulence that happens when the vessel is constricted. Can make them even louder by inflating the cuff quickly, or by raising the arm. CanÂ’t hear them before cuff is inflated because artery is not occluded, so blood is filling the artery, flowing normally.
If blood pressure was measured at the level of the subjects calf rather than at the level of the upper arm, would you expect the systolic and diastolic pressure readings to be different?: Pressure readings would be different, as there is more peripheral resistance at the leg due to the longer length of the vessels, and more blood in the vascular bed there. They should not be very much different, however.
explain how blood returns to the heart Â– why should one cool down after vigorous exercise rather than stop abruptly?: venous return system. Returns via heart pump, venous valves, muscular pump, respiratory pump Â– cool down avoids lactic acid buildup, plus pumps blood back to heart allowing venous and arterial to equalize while heart is returning to normal cardiac output.
What does this mean? standard error of prediction of VO2 max by this test is 15% in moderately tested individuals. see page 260 LEHSF: Acceptable range of +/- 15% in results.
VO2 max procedures: medical history form, informed consent form, heart rate monitor, respiratory valve, ergometer. warm up period. increasing exercise intensity every two minutes. discontinue test if any problems. measure gas every two minutes to start, then every one minute once into test. Gas is analyzed, temp and pressure are noted. heart rate taken every minute.
the following data were obtainedÂ… (given data on the exam) calculate this subjects VO2 max . show your calculations.: go over what calculations mean.
How would the predicted VO2 max of a 40 yr old subject be affected if the age correction factor was not used?: VO2 max peaks at about age 25, then goes down afterwards. If the age correction factor is not used, the 40 yr olds results would seem very poor when compared to the expected results of a younger fit, peak VO2 max individual.
do you think that the astrand bicycle ergometer test for predicting vo2 max is a good physical fitness test? explain.: Yes Â– it is economical, reproducible, has standards for comparison, is valid for what it is measuring for, and can be reliably administered.
you have been asked to set up a lab for testing maximum oxygen consumption. itemize the equipment you need.: ergometer, metronome, stopwatch, two way breathing valve with mouthpiece and head support, ventilation meter, plastic hose with connection to connect to respiratory valve and meter, nose clip, large bags for collecting gas, heart monitor, gas analyzer, thermometre, barometer, weighscale
in the maximum oxygen uptake test, what is the purpose of measuring barometric pressure and gas temperature?: respired saturated gas and volume are measured at ambient temperature and will need to be corrected to body temperature and pressure saturated in order to be correct. To apply correction factor, we must first know the actual ambient temperature and pressure which we measure with a thermometer and barometer.
what is the partial pressure of a gas, what is vapour pressure?: partial pressure exerted by the vapour phase of a liquid
list two criteria which an be used to determine whether or not a subject has really run to exhaustion and reached VO2 max, in a maximum oxygen uptake test performed on a treadmill.: heart rate close to age-predicted max,o2 consumption ceases to increase linearly with increased workload,
give a physiological explanation for the shape of a typical graph of VO2 versus workload.: VO2 max consumption continues to a peak, then ceases to increase linearly with increased workload. The lungs reach a point where they are taking in, and the circulatory system is distributing the maximum amount of o2, and the body can simply not output any more o2 despite the increasing workloads, because the hemoglobin is fully saturated, arterioles in skeletal muscle are fully dilated, and max temp has been reached Â– max o2 is already being taken from blood by tissues, - not physically possible to uptake any more o2, thus vo2 max.
is it more appropriate to express VO2 max in litres per minute or in milliliters per kilogram of bodyweight per minute? explain: heavier people tend to consume more o2 due to larger tissue mass. converting o2 per unit of body weight equalizes differences between different sizes of subject.
outline the chain of steps in the movement of oxygen from room air to its ultimate utilization in skeletal muscle. Which link in the chain usually limits oxygen transport and uptake during maximum exercise in healthy individuals?: 02 Â– nasal passages-pharynx-larynx-trachea-bronchi-bronchioles-alveolar passages-alveoli-RBC/hemoglobin-alveolar capillaries-pulmonary veins-left atria-mitral valve-left ventricle-aortic valve-aorta-systemic arteries-arterioles-capillaries-tissues-dissociates to tissues-used by tissues in aerobic metabolism. Limiting factor is the ability of the person to use the oxygen present in the blood.
draw the reflex arc for the patellar tendon tap. what role does the muscle spindle play in the knee jerk reflex?
distinguish between the direct light reflex and the consensual light reflex.: direct light reflex is where the pupil of the eye has light shone directly into it. consensual reflex is where the pupil of the other eye also contracts during this.
a subject was asked to perform a juggling task. she carried out ten trials. in the first and last trials she used her left hand. in trials two to nine she used her right hand. She attempted 50 tosses in each trial. A correct response was achieved when a: bilateral transfer, hand-eye coordination, speed, control.
what evidence is there that neither a negative transfer or a bilateral transfer took place during the course of your mirror trace experiment?: no bilateral transfer as learning with one hand didnÂ’t help other hand- mirror image, plus non preferred hand. didnÂ’t impinge on learning either, so no negative transfer.
where does the greater linear velocity exist in a lever: distal end of a longer lever
why do changes in momentum occur?: changes in velocity rather than mass
where is approximate CofG in men?: 57% of height
where is approximate CofG in women?: 55% of height
what happens when the H+ concentration of blood goes up: pH goes down
what is autorhythmicity?: ability to self-generate electrical impulses
what causes redistribution of blood flow due to vasoconstriction of arterioles supplying inactive areas & vasodilation to active areas during exercise (i.e. to skeletal muscle)?: increased temp, increased CO2lactic acid increaseo2 decrease
best measure of cardiorespiratory function?: ability to transport and utilize o2 (stroke volume, heart rate, o2 content, difference between arterial and venous blood)
study of laws of blood flow: hemodynamics
which is the better buffer? hemoglobin or oxyhemoglobin: hemoglobin
summarize the conduction of signals through the heart: originates SA node (right superior atrium) Â– spreads through RA and L atria (some via internodal tracts-specialized conducting pathways) Â– activates AV node (right atrium near AV junction)-short delay while atria finish filling ventricles Â– AV node depolarizes interventricular septum via bundle of HIS conducting cells (R&L branches Â– one to each ventricle) Bundle of HIS branches to purkinje system throughout ventricles Â– coordinated ventricular contraction (functional synctium)
heart murmurs caused by: when a valve doesnÂ’t close properly Â– causes blood to regurgitate back through valve, causing murmur sound.
heart muscle name and type: myocardium Â– cardiac
describe cardiac muscle: functional synctium Â– works as one unit Â– anatomically interconnected cells via intercalated discs
what is ventricular fibrillation: ventricles contracting without atrial contraction
how do blood vessels vary: presence of smooth muscle, thickness of vessel wall, amount of smooth muscle.
aorta diametre?: 25mm
arteriole diameter: usually less than .5mm
smooth muscle around arterioles?: extensive
size of capillaries?: 10micrometers, SINGLE layer of epithelial cells, LARGE surface area (site of gaseous exch)
order of blood vessels: aorta-arteries-arterioles-capillaries-venuoles-veins-vena cava
pressure differential between left ventricle versus right atrium: 117 mmHg difference, 120mmHg-LV, 3mmHG RA.
Normal healthy adult hemoglobin: males 15.5 gms/100ml blood, females 13.5 gms/100ml blood
what two factors are diffusing capacity in the body a function of?: volume of o2 crossing alveolar capillary membrane per minute, and the Hg pressure difference between alveolar air and pulmonary capillaries.
Is heart rate higher when exercise performed with arms or legs?: arms
how much blood makes up the functional residual volume of the heart?: 50-80 ml Â– or about 40-50%. Only 50-60% pumped out at rest.
what is the intima?: innermost layer of arterial blood vessels which release vasodilators
Why measure o2 consumption?: 1. canÂ’t directly measure energy consumption used for cellular processes, 2. o2 consumption provides indirect energy measurement Â– can translate into calories.
what is the respiratory quotient?: RQ = ratio of CO2 production to o2 consumption at cellular level. tells us the proportion of fuel components being used.
what does exercising at 5 met level mean?: five times the resting metabolic rate
what are five main physiological determinants of VO2 max?: ability to take in oxygen Â– ventilate lungs and blood passing through lungs, ability of blood to carry o2 (RBC number, and Hg concentration), ability of heart to pump blood, ability of working musc. to accept alrge blood supply, ability of musc. to extract o2 from capillary blood to use it for energy production, (fibre type, mitochondrion density, oxidative enzyme concentration)
VO2 max limitation?: persons ability to utilize o2 present in blood
three major proprioceptors: muscle spindles, golgi tendon organs, and pacinian corpuscles.
what do joint receptors do (pacinian corpuscles): relay information that contribute to sense of body awareness and limb position.
what does the somatic division of the efferent system of the PNS innervate: skeletal muscle
what does the autonomic division of innervate: smooth muscle, cardiac muscle, glands
what percent of neurons are interneurons?: 99%
where are interneurons located?: CNS only.
How are nerves classified?: diameter, conduction velocity, function
Summarize nerve impulse: membrane potential exists across nerve membrane, which is selectively permeable. inside nerve is negative, outside more sodium, so positive. stimulus causes chemically gated channels to open, sodium rushes into nerve, polarity reverses. action potential speeds along fibre via electrically gated channels.
what does inhibition of a nerve fibre cause?: hyperpolarization (makes it more difficult for an action potential to occur)
what does excitation of a nerve fibre cause?: polarization.
what is the main neurotransmitter?: acetylcholine.
What is a type two Â“aÂ” fibre: fast twitch, slow fatigue
what is a type two Â“bÂ” fibre: fast twitch, fast fatigue
what is the extrapyramidal tract concerned with?: posture and coordination of large muscle groups
what area of the cns is concerned with the acquisition of specialized motor skills?: premotor area
what area of the cns is concerned with the acquisition of specialized motor skills: premotor area

Start Studying!

Deck Info

Number of cards 251