KIN 100 1st Edition Lecture 7Circulation and Exercise○ Provides■ energy substrates■ O2○ Removes Metabolic end products■ H+■ CO2System Components● Heart○ Left Ventricle (LV)■ most important part in terms of exercise■ pumps blood from heart out to body● What determines how much blood is pumped? Is circulation limiting?○ Limiting Factors■ Heart Rate (HR)- beats/ min● resting heat rate○ HR when at rest○ decreases with training○ increases with increase in altitude and at temp extremes● HR increases with exerted effort● Maximal HR○ fastest a heart can beat○ HR max= 220-age■ Stroke volume (SV)● amount of blood pumped per heart beat● depends on LV size○ Left Ventricle■ Size matters■ Clarence de Mar● Famous marathoner● autopsy revealed he had a very large left ventricle and heart in general○ started research into if increase in LV size couldbe beneficialHeart Size for Various Groups■ Heart size needs to be normed to body mass● heart mass/body weight● Summary○ Cardiac Output (Q)■ (Q) = HR x SV■ limiting factor in exerciseHeart Rate Variability○ variety in time between heartbeats○ heart rate is average time● too much variability- arrhythmia● too little variability also bad○ more prone to cardiac incidents● variability increases with aerobic exerciseBlood Pressure (BP)■ peripheral resistance to blood flow■ measured with a sphygmomanometer○ 2 components■ systolic● highest blood pressure■ diastolic● lowest blood pressure○ variability ~7 mmHg● Measuring BP○ inflatable cuff placed around arm and inflated until blood flow stops■ can’t hear tapping in stethoscope■ exceeds systolic pressure○ decrease pressure slowly○ pressure when tapping stops= systolic pressure○ pressure when no sound= diastolic pressure● BP changes with exercise○ systolic BP increases greatly○ diastolic BP increases slightly● BP= cardiac output x total peripheral resistance○ can algebraically solve for peripheral resistance● Can study peripheral resistance with an ultrasound○ uses sound and electronic energy○ transduction: conversion of energy from one form to another○ Ultrasound■ produces high frequency pulses which produce sound waves■ reflected sound waves are reduced by objects■ machine displays distances and intensities of echosBlood Distribution● During rest● During
View Full Document
Unlocking...