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115 Cards in this Set
- Front
- Back
the bodys ability to acquire, convert, store, and utilize energy |
bioenergetics
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the immediate source of energy for all cellular activities is
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ATP
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ATP is broken down into _____
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ADP and Pi |
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this energy pathway is composed of ATP and phosphocreatine stored in muscle fibers
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phosphagen system
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an enzyme active in the phosphogen system
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creatine kinase
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stored ATP and PCr can sustain activity no more than
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30 seconds
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this system is sometimes referred to as the anaerobic pathway because oxygen isnt required for it to produce ATP; in this system only carbs can produce ATP.
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nonoxidative system
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the breakdown of carbs yields _____ which can contribute to muscle fatigue
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lactic acid
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the main provider of energy to the working muscle in athletic events lasting from 30 seconds to 3 minutes
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nonoxidative system
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also called the aerobic system because oxygen is required for it to proceed; both carbs and fat can synthesize ATP here
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oxidative system
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the metabolic by-products that result from oxidative phosphorylation are ____ and _____
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water and carbon dioxide
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the main provider of energy in events lasting over 3 minutes
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oxidative system
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the energy intensity at the oxidative system is referred to as the
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anaerobic threshold or the lactic threshold
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has been shown to increase the capacity of the oxidative system to produce ATP and is contributed to mitochondrial density in muscle from this
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endurance training
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the most abundant muscle in the body which has been specialized to enable mobility or mvmt and accounts for 50% of the human bodys mass. it is composed of individual cells termed myocytes or myofibers
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skeletal muscle
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a layer of connective tissue wrapped around each myofiber
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endomysium
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150 myofibers bundled together form the _____ which is encased in a layer of tissue called the perimysium
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fasciculus
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the layer of connective tissue that surrounds the entire muscle
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epimysium
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an individual myofiber may posess _____ nuclei/mm of fiber length
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200-300
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richly developed in the myofiber as the calcium it stores is needed to stimulate muscle contraction
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sarcoplasmic reticulum
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the plasma membrane of the myofiber
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sarcolemma
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electrical stimulation of the myofiber is through the
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action potentials
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these filaments account for approx 60% of the protein content in myofiber
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actin and myosin
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the larger protein sometimes referred to as the "thick filament"
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myosin
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the smaller protein termed "thin filament"
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actin
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regulatory filaments that are essential in triggering the contractile event
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troponin and tropomyosin
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have slow twitch properties but high oxidative capacity
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type 1 fibers
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have fast twitch properties but low oxidative potential
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type 2b
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have intermediate properties both in twitch velocity and oxidative capacity
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type 2a
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exercise of high intensity and short duration is principally powered by
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type 2 myofibers
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exercise of low intensity and long duration is principally powered by
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type 1 myofibers
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are both essential to the generation of the myofiber twitch
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regulatory and contractile filaments
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explains how protein filaments interact to produce a twitch of the fiber
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sliding filament theory
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the nervous system excites the ____ and _____
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myofibers sarcolemma and its t-tubules
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when a shift in the shape of tropomyosin occurs ____ on the actin filament are exposed
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active sites
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bind to the exposed sites of actin
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cross bridge heads
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cleaves ATP which results in the power stroke that pulls actin toward the center of myosin molecule which results in the fiber shortening and force generation
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ATPase
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responsible for delivering cytosolic calcium back into the sarcoplasmic reticulum thus returning the myofiber to a relaxed state
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calcium pump
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a single motor neuron and all the myofibers it innervates
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motor unit
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allows the body to breathe by exchanging gases with the environment
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pulmonary system
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air is taken into the lungs
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inspiration
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air leaves the lungs and reenters the environment
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expiration
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passageways through the nose and mouth join at the
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pharynx
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inhaled air passes through the ____ then the cartilage lined ____
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larynx, trachea
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two bronchi lead into each of the two
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lungs
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the bronchi divide to form numerous
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bronchioles
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at the end of each bronchiole is a cluster of
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alveoli
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the inspiratory muscles contract to expand the volume of the thoracic cavity and the diaphragm moves toward the abs while the external intercostal muscles pull the rib cage up and down
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inspiration
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involves the relaxion of the inspiratory muscles and return lungs to their original dimensions
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expiration
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the volume of air either inspired or expired over the course of 1 minute; at rest this is about 6L per minute
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VE
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also called minute ventilation
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VE
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during max intensity exercise minute ventilation may be
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20 to 25 fold higher than typical 6L per minute
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the amount of air entering of leaving the lungs in a single breath
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tidal volume
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in untrained individuals anaerobic threshold occurs at ____ of a persons maximal aerobic capacity
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55%
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in trained individuals anaerobic threshold occurs at ____ of their VO2 max
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80 to 85%
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the exercise intensity at which blood lactate levels rise and muscle fatigue sets in
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anaerobic threshold
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the anaerobic threshold is also referred to as the OBLA or
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onset of blood lactate accumulation
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composed of the heart and blood vessels
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cardiovascular system
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carry blood throughout the body
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blood vessels
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the hearts major muscle
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myocardium
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the four chambers of the heart
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2 upper atria and 2 lower ventricles
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receives blood from the lungs
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left atrium
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receives blood from all other parts of the body
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right atrium
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pump blood into ventricles and drive blood to the lungs and rest of the body
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atria
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the right and left sides of the heart are separated by the
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septum
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contract in unison
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2 atria; 2 ventricles
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when ___ is resting ventricles work, when ____ is resting atria work
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atria, ventricles
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the sequence of events during the hearts pumping action
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cardiac cycle
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the contractile phase of the myocardium
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systole
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the relaxation phase during contractions
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diastole
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the volume of blood ejected with each ventricular contraction
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stroke volume (70 mL at rest)
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the number of times the heart contracts per minute; about 72 bpm at rest
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heart rate
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the amount of blood pumped from the heart by each ventricle per minute
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cardiac output (at rest 5L per min)
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the amt of blood in each ventricle at the end of the resting phase or cardiac cycle; normal would be 125mL
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end diastolic volume
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end diastolic volume will significantly affect stroke volume because the greater volume of blood in the ventricle the greater the stretch on the myocardium
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frank starling law
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the volume of blood remaining in each ventricle following its contraction; normal would be 55mL
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end systolic volume
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the percentage of blood in the ventricle during diastole that is actually pumped during systole; sometimes defined as EF= SV/EDV; typically 60% but can range from 50 to 75%
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ejection fraction
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chronic aerobic training has no impact on max HR but ___ is significantly lowered
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resting HR
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stroke volume has greater intensity in a ____ position than a ____ position
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supine (swimming), upright (running, cycling)
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thick walled large diameter vessels that carry blood away from the heart
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arteries
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the largest artery, which directly receives blood from the left ventricle
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aorta
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blood pressure is highest in the
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arteries
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each artery branches off to form ___ which have lower blood pressure
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arterioles
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each arteriole has 3 to 5 ____ and each is barely smaller than a red blood cell; very thin walls allow for exchange of nutrients and gases
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capillaries
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several capillaries join to form a _____ and this begins the return of blood to the heart
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venules
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a number of venules form a larger ____ and these ultimately return blood to the heart
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veins
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ensure unidirectional blood flow through this network and allow for the circulation of blood within the entire body
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one way valves
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blood flow is greater with increased demand for blood in exercising muscle
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vasodilation
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blood flow is reduced to satisfy working muscle
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vasoconstriction
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because the heart pumps blood in a pulsatile blood pressure
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oscillates
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the resistance of vessels to blood flow
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afterload
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the amount of blood in the ventricle immediately before contraction
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preload
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healthy blood vessels demonstrate high ____ easing the burden of the heart
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compliance
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artherosclerosis decreases arterial _____ and increases blood pressure
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compliance
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the pressure exerted on the arterial walls during the contraction of the left ventricle; is about 120 mm Hg in resting individuals; above 140 leads to hypertension
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systolic
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the pressure exerted on arterial walls during resting between ventricular beats; in healthy adults the norm is 80mm Hg; above 90 leads to hypertension
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diastolic
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the difference between systolic and diastolic pressures
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pulse pressure
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the average pressure exerted through the entire cardiac cycle
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mean arterial pressure
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also called the double product and is a correlate of myocardial oxygen uptake and hence the workload of the left ventricle
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rate pressure product
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occurs via vasoconstriction and takes blood from the visceral organs to the active skeletal muscles; has a dramatic effect on the distribution of blood
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shunting
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a systolic pressure over ___ should lead to immediate cessation of exercise
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260 mm
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accounts for 8 percent of a persons body weight and is composed of plasma along with several types of cells
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blood
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comprises about 55% of blood volume in men and 58% in women; its main component is water and also has proteins, electrolytes, gases, nutrients, waste products, and various hormones
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plasma
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a protein that is found only in erythrocytes (red blood cells)
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hemoglobin
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the most abundant cell types in blood and account for 99% of the bloods cells
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erthrocytes (red blood cells)
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carries 30% of carbon dioxide transported by blood
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hemoglobin
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a measure of the percentage of the bloods volume that is composed of erthrocytes
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hematocrit
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the avg hematocrit in men
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45%
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the avg hematocrit in women
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42%
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also called white blood cellsand their primary function is to destroy potentially infectious agents that enter the body
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leukocytes
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fragments of much larger cells which accumulate and form a plug where damage has occured to the blood vessel wall and prevent loss of blood
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platelets
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an increase in the volume of blood delivered to the working muscles which allows a greater delivery of oxygen and nutrients and removal of carbon dioxide and waste by products
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hyperemia
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serves to prevent overheating of the body by having more water for sweating
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cardiovascular drift
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apparent in elevations in hematocrit and hemoglobin values
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hemoconcentration
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long term effects of training on blood
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increases erythrocytes, plasma volume increases, oxygen carrying capacity, higher SV and lower HR
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