KNES 360 week 4
KNES 360 week 4 KNES 360
Popular in Physiology of Exercise
Popular in Kinesiology
This 5 page Class Notes was uploaded by Lindsay Burns on Tuesday September 29, 2015. The Class Notes belongs to KNES 360 at University of Maryland taught by Dr. Rogers in Fall 2015. Since its upload, it has received 116 views. For similar materials see Physiology of Exercise in Kinesiology at University of Maryland.
Reviews for KNES 360 week 4
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/29/15
KNES 360 Lecture Week 4 92115 The composition of Total blood Volume TBV gt Men 56 Lmin gt Women 45 Lmin o Differ due to mass 0 Does not change much from rest exercise 0 Higher in endurance trained athletes gt Hematocrit 0 Norm 4045 Women 38 42 If exceeds 60 blood is too viscous and cannot ow readHy 0 Blood Contains Plasma 55 0 90 water 0 7 plasma proteins 0 3 other Formed elements 45 0 gt99 RBC 0 lt1 WBCplatelets o Hematocrit 45 formed elements 100 TBV 0 Men have higher oxygen carrying capacity and larger pump 0 Increases in response to greater endurance training and higher altitude gt RBC ReInfusion 0 Freeze blood so when reinfuse the blood one has greater amount of RBC s Increases TBV 10 gt EPO o Hormone produced by the kidneys During exercise training and high altitude gt Cardiac performance 0 Stroke volume SV amp Cardiac output Q increase 0 V02max gt Pressure changes across the systemic circulation 0 Resistance nL Poiseille s Law rquot4 n Viscosity of uid 0 Increases resistance L length of tube r radius o Relatively small changes in r make huge changes in resistance 0 Blood ow B Change in Pressure Resistance As pressure increases blood ow increases As resistance increases blood ow decreases 0 Need mechanisms to return blood to right side of heart How is blood ow back to the heart increasing during exercise 0 1 Ventilatory pump 0 2 Muscle pump 0 1 amp 2 increase venous return 0 3 Valves in large veins l Prevent BF from going backwards 4 Vasoconstriction increase SNS 0 Signi cant increase SNS activity rest exercise 0 Increase HR amp contractility 92315 Hemodynamics gt Stroke Volume SV Difference between enddiastolic EDV and end systolic volume ESV 0 After exercise diastolic is greater and systolic less and SV increases gt Ejection fraction EF 0 Fraction of blood ejected when the heart contracts I SV x 100 EDV o Increases with exercise in normal person 0 Greater ejection of blood to aorta 0 Heart disease decreases EF Congestive heart failure CHF 0 Less capacity to contract vigorously Cardiac bers stretched Coronary artery disease CAD Heart attack patients gt Cardiovascular quotBig Picturequot 0 Intrinsic and extrinsic control mechanisms 0 Systolic and diastolic phases of cardiac cycle shorten when one goes from rest exercise 0 All 4 cardiovascular tubes are important for redistribution during exercise 0 Capacity to vasodialate from arterioles in active skeletal muscle critical aerobic exercise o 4 major hemodynamic variables change from rest exercise Module 2 gt Cardiac Output Q 0 Q HR x SV Q Lbeatmin HR bpm SV mLbeat How is Q measured 0 1 Cardiac catheterization At rest 0 2 Doppler Ultrasound method Noninvasive o 3 C02 Rebreathing Directly related to blood ow Most common method 92515 Rebreathing o Anesthesia bag N2 02 Exchanged in lungs Breath out in bag Content samples in machine Non invasive way to measure cardiac output Resting Q values for endurance athletes and sedentary control subjects are the same 0 Depends on size of individual Larger the person larger the heart larger blood volume the gt cardiac output Q If HR is slower there is more time for the ventricle to ll with blood 0 Greater diastolic 0 Greater SV 0 Greater period of diastole gt Distribution of Q at rest and exercise Blood Flow at rest Blood Flow during exercise Visceral Organs 45 10 Heart 5 no change rate 34x 5 Bone 5 1 Brain 15 dec Absolute inc 4 lntegumentary 5 520 Muscles active 20 7085 o Vasoconstriction to visceral organs 0 Vasodilation in active skeletal muscle gt Fick Principle 0 Q V02 av 02 dif a arterial v mixed venous gt Frank Starling mechanism important response to exercise 0 Greater stretch greater contraction gt Most basic relationship in cardiovascular exercise physiology 0 Relationship between HR and work rate gt Maximum heart rate has little effect from endurance training but from age gt Stroke Volume 0 Noninvasive way of accessing SV 0 Echocardiogram Measure end diastolic blood volume Systolic volume Size of chambers Thickness of walls Volumes in end diastole Just after contraction systolic o SV EDV ESV o SV increases signi cantly during exercise 50 V02max then SV levels off Linear then levels off 0 Q linear 0 HR linear gt Well trained endurance athletes o Bigger heart 0 Larger left ventricle Size of chamber Thickness of walls 0 Greater TBV o SV may not level off until about 8590 V02max gt 4 factors affect SV 0 1 Venous return Enhanced by 0 Ventilartory pump 0 Muscle pump Unidirectional valve Vasoconstriction o 2 Ventricular distensibility o 3 Ventricular contractility o 4 Aortic pressure Inhibiting factor Resist ventricular uptake Aortic pressure increases as SV decreases